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Alternator/cable upgrades

Cottontail

Cottontail

Three-De Off-Road
NAXJA Member
Location
Nashville, TN
Ok...I'm going to pull the trigger on the ZJ alternator sometime in the very near future. Got a lot of searching done last night and bookmarked 3 pretty good write ups. However, here are my questions.

1. Anyone with a good write up on making and replacing upgraded cables? Lots of incomplete write ups with lots of technical jargon. I found this (http://www.bc4x4.com/tech/2004/jeepalt/) write up in about half a dozen threads, but it is a dead link. This seems to be the most intimidating part of the upgrade to me as I understand very little about the electronics under the hood...especially the parts about adding in fuses....and there just seems to be a mess of wires under my hood! I would prefer to follow a write up and make my own rather than buy them, just for the hands on learning experience.

2. Any way to determine if a junkyard if an alternator is good or crap?

3. There seems to be a small contingency of posters in the 10 or 12 threads I read through last night that beleive in a 2001 I don't need to upgrade the wiring if I am only using OEM items...meaning I am not powering extra lights, a winch, an amp or sub, etc. Thoughts?

4. There was also some talk about just going grande and getting the 160 from a Durango rather than stopping at the 136. I am guessing without the need to power a bunch of crap that is just over kill?
 
Get Jon's (5-90 on here) mains upgrade kit. www.geocities.com/JeepI6Power/electric.html

Even on a stock system, your starter and the rest of your electrical system will be improved. The cables are top notch and bolt right on. He carries two sizes of cables depending on the size of the alternator. If you go big, you will need his ANL upgrade as well.
 
Which jeep is it for? The XJ harness connector changed in 97, so the alternator options are different between your 96 and 01.

For the power supply wires, you would need to buy some 4ga fine-strand welding wire and some copper ends, solder the ends to the wire and cover them with heat shrink tubing. You will want positive (red) wires for alternator to battery, battery to ECU, and battery to starter. You will want ground (black) wires for battery to engine, battery to fender (body), and firewall (body) to engine block. You will need an inline fuse between the alternator and battery positive to protect the rest of the system from the alternator overcharging. The other option (and what I did) is go buy a pre-made set from 5-90

Only way to really test an alternator at the junkyard is to spin the pulley and listen/feel for any dirt in the bearings. If it's rough then it may need to be rebuilt, which will cost almost as much as buying a reman somewhere.
 
1. The way I did the cables was marked where they went and then pulled them. Took them to the auto parts store and got all the correct length ones to replace them and added a 150amp mega fuse (went with the 136amp ZJ alt).

2. Not sure if they make a portable alt tester, jy you are at might have one on site and they can test it for you. If you want peace of mind get a new or remaned one with a warranty.

3. I would think if you are increasing the amp output of the alt then you would need to upgrade the wiring no matter the year.

4. There is no such thing as over kill on a trail rig plus you may one day decide to add a winch, lights, etc and already have the bigger alt.
 
Danger Dave said:
Get Jon's (5-90 on here) mains upgrade kit. www.geocities.com/JeepI6Power/electric.html

Even on a stock system, your starter and the rest of your electrical system will be improved. The cables are top notch and bolt right on. He carries two sizes of cables depending on the size of the alternator. If you go big, you will need his ANL upgrade as well.
Click to expand...

Agreed. I made mine myself because I was pressed for time and didn't want to pay for shipping. The price difference was minima. I made mine out of zero gauge welding wire. I just removed the old cables and measured them. I also used a mega fuse from napa. I had my ends crimped for me at Napa, but ultimately bought a chinese crimping tool for $20. I have one ground wire left to finish.
 
Just to clarify, does the mega fuse inline with the alt to battery?

jeepman75 said:
1. The way I did the cables was marked where they went and then pulled them. Took them to the auto parts store and got all the correct length ones to replace them and added a 150amp mega fuse (went with the 136amp ZJ alt).

2. Not sure if they make a portable alt tester, jy you are at might have one on site and they can test it for you. If you want peace of mind get a new or remaned one with a warranty.

3. I would think if you are increasing the amp output of the alt then you would need to upgrade the wiring no matter the year.

4. There is no such thing as over kill on a trail rig plus you may one day decide to add a winch, lights, etc and already have the bigger alt.
Click to expand...
 
Last edited by a moderator:
praetorian said:
Just to clarify, does the mega fuse inline with the alt to battery?
Click to expand...

Correct. There is an OEM fuse device inline (probably a segment of fusible link wire, you're OBD-II, right?) which needs to be restored - and usually upgraded.

Selecting a rating of fuse is fairly easy - take the rated max output of your alternator (or the actual max output, if known) and select the fuse that matches that or the very next rating higher. (I say "actual if known" - actual can be 95-110% of rated, typically. However, you won't always get full output - you'll get whatever the regulator thinks you need. And, the greater the difference between "max rated" and "typical running" output, the longer the thing will last for you...) So, if you've got a 136A alternator, look for a 150A fuse. A 160? Look for a 175. 150? You can use either a 150A fuse or a 175A fuse.

Form factors of fuse that will likely have useful ratings for this include: ANL, Mini ANL (MANL,) MEGA, and AGU (although the AGU is a glass tube, and therefore relatively fragile.) The MEGA fuse started as an industrial part, but I understand NAPA now has them - probably because Ford has been using them OEM for the last couple of years now. ANL and MANL are typically found in autosound supply houses, as they're quite popular there. MEGA and ANL fuses are gaining ground in marine applications as well.

ANL fuses can be found in ratings of 60-600A (typical steps are 60, 80, 100, 120, 125, 130, 150, 175, 200A, and every 25 or 50A thereafter,) MEGA fuses have been seen from 100-1,000A (typically steps of 25-50A as well,) and I'm not sure where AGU fuses top out, but I've seen them up to 300A. Ratings I've seen for MANL fuses have run 50-200A, but I somehow think that isn't the gamut. No particular idea on steps (I have some MANL175 fuses I got by mistake, and I need to investigate that more fully. I'd thought that series topped out a bit lower...)

The fuse should be wired such that it would isolate the alternator if it blows - therefore, it goes between the alternator at the primary distribution point (in your case, the PDC input.) This is to help prevent damage in the case of an "alternator surge" - where the field coils get switched to full operating 12VDC. The resultant spike typically runs 90-100VAC @ 600-800A!

(No, I didn't edit your post. I hit the wrong button...)

("Praetorian." As in "Praetorian Guard," from the old Roman Empire? I feel like we may have talked about this before, but I'm drawing a blank...)
 
I pulled the cable out os a late model Taurus from my local JY and paid a buck for it. The ford had a 175Amp charging system in it... Just sayin that shortening the cable and putting on an end is a cheap solution.
 
if you want to upgrade all the wiring pm jon (5-90) he helped me out with my wires and it made life so much easier. really great guy to work with.

that's about all i can contribute here hahaha
 
o-gauge-steamer said:
I pulled the cable out os a late model Taurus from my local JY and paid a buck for it. The ford had a 175Amp charging system in it... Just sayin that shortening the cable and putting on an end is a cheap solution.
Click to expand...

Be careful - Ford is notoriously cheap on their wiring. I've wired up a few "emergency vehicles" for corporate campuses, and there was invariably TSBs on the lighting controllers and stuff to the effect of "Don't do this on a Ford - except one that is a dedicated LE vehicle from the factory - if you don't want to burn it down."

Specifically Ford.

Considering I've worked on a couple of Explorers that had MEGA175 main charging fuses and 8AWG charging leads, I'm a bit worried (OEM on the Jeep lead is 6AWG - works for the duty cycle they anticipate, but I consider it a little light if you want to get more use out of an upgraded alternator...)
 
Cottontail said:
Ok...I'm going to pull the trigger on the ZJ alternator sometime in the very near future. Got a lot of searching done last night and bookmarked 3 pretty good write ups. However, here are my questions.

1. Anyone with a good write up on making and replacing upgraded cables? Lots of incomplete write ups with lots of technical jargon. I found this (http://www.bc4x4.com/tech/2004/jeepalt/) write up in about half a dozen threads, but it is a dead link. This seems to be the most intimidating part of the upgrade to me as I understand very little about the electronics under the hood...especially the parts about adding in fuses....and there just seems to be a mess of wires under my hood! I would prefer to follow a write up and make my own rather than buy them, just for the hands on learning experience.

2. Any way to determine if a junkyard if an alternator is good or crap?

3. There seems to be a small contingency of posters in the 10 or 12 threads I read through last night that beleive in a 2001 I don't need to upgrade the wiring if I am only using OEM items...meaning I am not powering extra lights, a winch, an amp or sub, etc. Thoughts?

4. There was also some talk about just going grande and getting the 160 from a Durango rather than stopping at the 136. I am guessing without the need to power a bunch of crap that is just over kill?
Click to expand...


1.) What question do you have I did mine this weekend. The hardest part was finding a home for the new ANL. If you remove one wire at a time and replace with a new one it is easy.

[FONT=&quot]2.) If and when you get an alternator, take it to advance auto parts or Oreilly’s and have them test it. I bought mine off ebay for $35.00. Ebay jeeprockstar has tons of parts for cheap. Also if you keep your stock brackets you will have grind the alternator holder to allow the larger alternator to fit. I install a upper wrangler bracket and a lower ZJ bracket so I did not have to grind anything. Here is a link if you are going install a larger alternator.
[/FONT] [FONT=&quot] http://www.jeepforum.com/forum/f11/5-9-alternator-upgrade-642951/

[/FONT] 3.) It is absolutely necessary to upgrade your wires! Jeep did the bare minimal to get by. Ever look at your cheapo grounding strap? Ask Jon ( 5-90 ).


 4.) 160amp versus 136amp? From what I read tons of people are fine with 136amp. If you do 160amp you would have to run 1awg. “If you're sure you're not going to go past a 150A alternator, 4AWG will be just ducky. Past 150A, and you're going to want 1AWG (the farther past 150A you go, the more you're going to want the heavier wire.)” From 5-90 to me.

If you have any questions PM me. I broke my phone over the weekend so I am in the process of trying to recover all the pictures I took.
 
PRYAPSM said:
1.) What question do you have I did mine this weekend. The hardest part was finding a home for the new ANL. If you remove one wire at a time and replace with a new one it is easy.

[FONT=&quot]2.) If and when you get an alternator, take it to advance auto parts or Oreilly’s and have them test it. I bought mine off ebay for $35.00. Ebay jeeprockstar has tons of parts for cheap. Also if you keep your stock brackets you will have grind the alternator holder to allow the larger alternator to fit. I install a upper wrangler bracket and a lower ZJ bracket so I did not have to grind anything. Here is a link if you are going install a larger alternator.
[/FONT] [FONT=&quot] http://www.jeepforum.com/forum/f11/5-9-alternator-upgrade-642951/
Click to expand...


Testing a breaker's alt has merit, but I wouldn't bother with the benches at AZ or AAP. I used to use (and occasionally service) those benches, and they do two things wrong:

- The testing spindle speed of the alternator runs around 1000-1500rpm. That's not enough to get anything like full output - you usually need a spindle speed of about three times that to make full output happen.

- They only test output voltage. Useful, but the current they draw isn't enough to power a decent flashlight.

Granted, I'm cranky about electrical anyhow - but if you insist on going to the breaker's for a 'new' alternator (vice doing it right and going to a local shop to get a unit remanned on-site,) take the 'new' unit to that local shop and have them test it for you. Chances are very good they'll be able to tell you the actual max output of the alternator, and be able to discern any potential failures you may be facing (rectifier diode ripple is typical, and presages a full-on rectifier failure.)
PRYAPSM said:
[/FONT] 3.) It is absolutely necessary to upgrade your wires! Jeep did the bare minimal to get by. Ever look at your cheapo grounding strap? Ask Jon ( 5-90 ).
Click to expand...


Concur. OEMs select wire gage under "ideal conditions" and assume a duty cycle of around 30-40% at full output.

Again, I'm cranky about electrical. I assume that if you're going to install an uprated alternator, you're going to want to use it - which means that you're going to need larger wiring (my assumptions are 100% duty cycle at full output, elevated operating temperatures, unfavourable conditions, and a minimum safety margin of 10%. Pessimistic? Perhaps. But you're not going to have an electrical fire because of me...)
PRYAPSM said:
4.) 160amp versus 136amp? From what I read tons of people are fine with 136amp. If you do 160amp you would have to run 1awg. “If you're sure you're not going to go past a 150A alternator, 4AWG will be just ducky. Past 150A, and you're going to want 1AWG (the farther past 150A you go, the more you're going to want the heavier wire.)” From 5-90 to me.
Click to expand...


Correct - but in either case, the OEM 6AWG is generally lacking. We plan to use full capacity a lot more than the design engineers at AMC or ChryCo expected us to, so it needs to be accounted for in the assumptions.
PRYAPSM said:
If you have any questions PM me. I broke my phone over the weekend so I am in the process of trying to recover all the pictures I took.
Click to expand...

I'm also happy to answer any technical questions you might have - PM me.

(I'm also willing to answer technical questions "out in the open" - but as soon as it turns to talk of "how much" and things like that, we need to go backchannel...)
 
praetorian said:
Yeah, I've discussed this with someone, probably you! HAHA!
Click to expand...

Quite probably - I wish people would stop hittin' me on my head...

(Fortunately, I do a better job of holding on to medical or mechanical/engineering information - but I use it a lot more!)

Now that I think about it and feel some things sifting into place, isn't it from HvAvP? A screen name in a video game world? Stop me if I'm wrong...
 
Alien VS Predator is actually where I learned the correct spelling, but yes, I think we discussed that too. Is this considered a hijack?
 
Cottontail said:
Ok...I'm going to pull the trigger on the ZJ alternator sometime in the very near future. Got a lot of searching done last night and bookmarked 3 pretty good write ups. However, here are my questions.

1. Anyone with a good write up on making and replacing upgraded cables? Lots of incomplete write ups with lots of technical jargon. I found this (http://www.bc4x4.com/tech/2004/jeepalt/) write up in about half a dozen threads, but it is a dead link. This seems to be the most intimidating part of the upgrade to me as I understand very little about the electronics under the hood...especially the parts about adding in fuses....and there just seems to be a mess of wires under my hood! I would prefer to follow a write up and make my own rather than buy them, just for the hands on learning experience.

2. Any way to determine if a junkyard if an alternator is good or crap?

3. There seems to be a small contingency of posters in the 10 or 12 threads I read through last night that beleive in a 2001 I don't need to upgrade the wiring if I am only using OEM items...meaning I am not powering extra lights, a winch, an amp or sub, etc. Thoughts?

4. There was also some talk about just going grande and getting the 160 from a Durango rather than stopping at the 136. I am guessing without the need to power a bunch of crap that is just over kill?
Click to expand...

1. everybody will have different opinions on how to go about it & what parts to use... its great to be hands on & learn, but when it comes time to tackle the project, u gotta decide whats easier & most convenient to get things done for u... its not extremely complicated upgrading charging/electrical system... it'd be beneficial to understand the "technical jargon", to in turn understand why, how, & where... some good reading... lots of good info... one more (i think its a 4-5 part article), very good info... i'm sure u've read about having to grind the alternator brackets... it's real basic, honestly self explanatory, take off the brackets & keep trimming/grinding just enough till the alternator fits into the brackets with bolt holes lined up

2. best bet is with a dedicated alternator/automotive electrical shop... like 5-90 said, AA or AAP arent as reliable with accuracy... couple tips, if u get a JY alternator, make sure u get it from the V8, & get it tested at a dedicated shop, & double check amperage output with them... JY i got my 136A, didnt "allow" me at the time to pick parts myself, so they gave me a 90A from an I6 4.0 ZJ... it failed AA test, but passed at AAP, both said it was a 136, then found out it was operating fine & it was 90A at the dedicated shop

3. it never hurts to upgrade a vehicles factory mains... probably not necessary to increase alternator output... y do it, if u dont need it?

4. not positive, but durango alternator might plug up directly using the male/female plug... mounting might be different... regardless, yea, i think overkill for ur set up... u'd be good with 5-90's mains

5-90 said:
Correct. There is an OEM fuse device inline (probably a segment of fusible link wire, you're OBD-II, right?) which needs to be restored - and usually upgraded.

Selecting a rating of fuse is fairly easy - take the rated max output of your alternator (or the actual max output, if known) and select the fuse that matches that or the very next rating higher. (I say "actual if known" - actual can be 95-110% of rated, typically. However, you won't always get full output - you'll get whatever the regulator thinks you need. And, the greater the difference between "max rated" and "typical running" output, the longer the thing will last for you...) So, if you've got a 136A alternator, look for a 150A fuse. A 160? Look for a 175. 150? You can use either a 150A fuse or a 175A fuse.

Form factors of fuse that will likely have useful ratings for this include: ANL, Mini ANL (MANL,) MEGA, and AGU (although the AGU is a glass tube, and therefore relatively fragile.) The MEGA fuse started as an industrial part, but I understand NAPA now has them - probably because Ford has been using them OEM for the last couple of years now. ANL and MANL are typically found in autosound supply houses, as they're quite popular there. MEGA and ANL fuses are gaining ground in marine applications as well.

ANL fuses can be found in ratings of 60-600A (typical steps are 60, 80, 100, 120, 125, 130, 150, 175, 200A, and every 25 or 50A thereafter,) MEGA fuses have been seen from 100-1,000A (typically steps of 25-50A as well,) and I'm not sure where AGU fuses top out, but I've seen them up to 300A. Ratings I've seen for MANL fuses have run 50-200A, but I somehow think that isn't the gamut. No particular idea on steps (I have some MANL175 fuses I got by mistake, and I need to investigate that more fully. I'd thought that series topped out a bit lower...)

The fuse should be wired such that it would isolate the alternator if it blows - therefore, it goes between the alternator at the primary distribution point (in your case, the PDC input.) This is to help prevent damage in the case of an "alternator surge" - where the field coils get switched to full operating 12VDC. The resultant spike typically runs 90-100VAC @ 600-800A!

(No, I didn't edit your post. I hit the wrong button...)

("Praetorian." As in "Praetorian Guard," from the old Roman Empire? I feel like we may have talked about this before, but I'm drawing a blank...)
Click to expand...

5-90 said:
Testing a breaker's alt has merit, but I wouldn't bother with the benches at AZ or AAP. I used to use (and occasionally service) those benches, and they do two things wrong:

- The testing spindle speed of the alternator runs around 1000-1500rpm. That's not enough to get anything like full output - you usually need a spindle speed of about three times that to make full output happen.

- They only test output voltage. Useful, but the current they draw isn't enough to power a decent flashlight.

Granted, I'm cranky about electrical anyhow - but if you insist on going to the breaker's for a 'new' alternator (vice doing it right and going to a local shop to get a unit remanned on-site,) take the 'new' unit to that local shop and have them test it for you. Chances are very good they'll be able to tell you the actual max output of the alternator, and be able to discern any potential failures you may be facing (rectifier diode ripple is typical, and presages a full-on rectifier failure.)



Concur. OEMs select wire gage under "ideal conditions" and assume a duty cycle of around 30-40% at full output.

Again, I'm cranky about electrical. I assume that if you're going to install an uprated alternator, you're going to want to use it - which means that you're going to need larger wiring (my assumptions are 100% duty cycle at full output, elevated operating temperatures, unfavourable conditions, and a minimum safety margin of 10%. Pessimistic? Perhaps. But you're not going to have an electrical fire because of me...)




Correct - but in either case, the OEM 6AWG is generally lacking. We plan to use full capacity a lot more than the design engineers at AMC or ChryCo expected us to, so it needs to be accounted for in the assumptions.



I'm also happy to answer any technical questions you might have - PM me.

(I'm also willing to answer technical questions "out in the open" - but as soon as it turns to talk of "how much" and things like that, we need to go backchannel...)
Click to expand...

LISTEN TO THIS MAN! very highly knowledged... he's dropped some good info here, if u dont understand it, do more researching

i also have a set of mains for my rig, they're beef & very well put together kit... has a kit that upgrades all the wiring & if u'r up-amping, appropriate fuse & fuse holder
 
Well... I upgraded my battery/ground cables and I have issues. I haven't touched the alternator yet though. I go to fire it up for the first time and the starter only hammers. It doesn't turn the engine over at all. It sounds really strong and louder than if it was a bad battery. Weird thing though, the powered door locks cycle when I let off the key. It didn't do this before. I rechecked all my new wiring, new grounds, and all appear to be done right. I got rid of the plastic connector that bolted to 2 of the posts on the starter solenoid and now the battery cable and green wire bolt directly to the starter solenoid. I can post up pics later if that would help. Everything worked fine before I delved into this starting Friday. I have a 98 4.0 with manual trans.
 
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