Another alternator question

Soooooo did this before on a 98 and it was pretty simple. This one not so much. Beefed up the grounds from the battery and was rewiring the power (positive cable) to the control unit (thing with the fuses and relays next to the battery) without a problem. I cut the bracket that connects to the two bolts and put it on the new battery cable.

Now I ran into an issue. Was tracing the main wire from the alternator and it doesnt go to the battery. It heads up into the wire loam. I pulled damn near everything out that I could and cant trace this wire. Can I just cut it and add an inline fuse going strait from the alternator to the battery?

Contact 5-90. He makes cables and such, and a guru about lots of this stuff. Others know too. But he is the one I know that can answer your question fully.

I tried but the email is no longer working

PM? http://www.kelleyswip.com/
I have a Renix, but IIRC the Alt pos cable goes the the junction area where the relays and stuff are on the pass side fender.

You can run a second cable from alt to battery leave stock one alone. Add second heavier cable from alt to fuse to battery.

The feed from the Alternator runs through what is rather amusingly called a "fusible link". What that really is, is a pice of wire undersized to take the current. If the Alternator starts pumping more current that the link is rated for, it burns out disconnecting the alternator until the wire is replaced.

When I installed my large Alternator, I also installed a proper fuse at the front of the Power Distribution Center (PDC). As it turns out, the mounts at the front of the PDC (late model) are perfectly spaced. Do a search against my screen name and you will find photos.

I then just used a properly sized wire from the Alternator to the Fuse.

Not being familiar with your year XJ, I have to assume that the connection from the Alternator (via the fusible link) is there. It will be a somewhat large wire as it has to carry 90 Amps.

I have a Nippondenso part #: DN13341NA200 200 Amp unit installed.

^^^Yup^^^ That is how it is done. The connection on the right is the input to the PDC, the left connection is from the Alternator.

Simple.

My power box doesn't have that type of connection. That's what I did when I upgraded another vehicle. This is what I did and its working so far

Main post from alternator to battery fused with 150amp
Battery to power distrib box fused with 150
Beefed up wire going from battery to starter

Now there is a stray red 12gauge looking red wire going into the loam from the battery that's no longer connected. The original wire harness thing connected to the alternator stayed put. Didnt change anything with those (little black box with 4 wires).

So far everything seems to be working. My voltage is staying just under 14v on the gauge. No fused blew and all my electrical is still working without combusting into flames. The connection you guys fused across on mine is an L bracket rounded at the top with two connection screws. I cut the bracket at the bend then secured it to the new cables.

Ok noticed an issue. The voltage gauge is showing just over 1/4 with the AC on and a little higher when it's off. I haven't got to test the connections with a voltmeter yet. Anyone know a good link on what should be reading what and where to test it? Ill google it of course but just in case someone had it bookmarked lol

RENIX used a 6AWG alternator output lead with a segment of 10AWG fusible link wire to protect the vehicle (fusible link wire is not only undersized, it's made of a low-melt alloy - similar to Wood's metal, I think - and uses a Hypalon insulation that makes heat damage quite obvious.)

OBD-I ran the alternator output lead up into the bottom of the PDC to a dedicated Buss bar, and there were a pair of MAXI50 or MAXI60 fuses between the secondary Buss and the main distribution Buss. OEM lead is 6AWG.

OBD-II went back to the 6AWG alternator output lead w/10AWG fusible link wire, as RENIX.

For OBD-I, there is a funky quick-connect under the PDC - this should be the other end of your alternator output lead. Disconnect this, and remove the two fuses labelled "Generator."

Then, run your new alternator lead to either the stud(s) on the front of the PDC, or run to the battery + post, via a fuse! (ANL, MEGA, or similar. Pick the rating that matches your alternator, or possibly the very next one higher.)

I do not, will not, and cannot recommend eliminating an OEM safety device without sourcing an equivalent replacement!

As far as the voltage drop with the aircon running - this is normal, and I've explained it. If you want to verify system voltage, do so with a decent DMM (Digital MultiMeter) and use the battery posts for the connection - they're easiest to access for a gross reading.

^^All of this is quite right. Under no circumstance do you eliminate the fusing. As for the voltage dropping when the A/C kicks in, some drop is to be expected. Just as the voltage will be lower in the summer months (provided the Jeep has a battery temperature sensor in it...).

How much of a drop is too much? Good question. A couple of volts should not cause any heartburn. As is always the case with XJs, all of the battery connections need to be cleaned. All of them. The connection most over looked is the negative post to engine block. Remove, clean and install all of the cabling from the battery. Every grounding point need to be cleaned as well.

Jeep, in their infinite wisdom, installed a 90 Amp Alternator. By the time you add up all of the current draw for the compressor clutch, the aux fan, ignition and the fuel requirements, most of the capacity is taken. With the Alternator running close to it's rated output, the voltage tends to drop.

Just one of the reasons to install a larger capacity Alternator. The ZJs came with a 136A unit as did some of the XJs. This Alternator bolts in without any need to modify the bracketry. My 200A (nominal...) Alternator required the brackets to be opened up to accept the larger case.

For instance:
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As you can see, it is of a size that does not fit into the stock brackets...

Sorry to take so long getting back. After I posted I ran a voltmeter and everything is showing fine under load and idle. I have a 150a ANL running between the battery and PDC and the alternator and battery just for precautions. My gauge in the cab just isn't accurate. So far the only things I'm seeing are brighter lights and faster start up.

5-90!!!!! You run the Kelly work in progress site right? I tried to email your yahoo and it got sent back saying the email address was no longer valid. I used one of the links on your page. Thought you sit down lol.

SBpunk said:

5-90!!!!! You run the Kelly work in progress site right? I tried to email your yahoo and it got sent back saying the email address was no longer valid. I used one of the links on your page. Thought you sit down lol.

Click to expand...

JeepI6Power AT yahoo DOT com? Got mail there this morning, and it's the addy I've always been using. I'm still around, as far as I know!

Your fuse setup - the fuse between the battery & vehicle isn't strictly necessary (if a battery provides too much current to a system under power, it's a fault of the system - the battery is a storage device, not a generator.) The fuse between the alternator and "everything else" is necessary - that's why the factory put it there.

What's yer question? You can PM me here as well, or try to email again using the address directly (but, AFAIK, it's still in service! Just finished answering a batch of messages that came in, in fact...)

It was just about where to put the fuse so I ender up over doing it a bit. I was going to grab some wires off you but I ended up using cheapo oreilly ones. Once I step it up to a 160 I'll be hitting you up for some 1 gauge.