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Freeing my 2000XJ from the external regulator life

R

robsjeepxj

NAXJA Forum User
Location
North Jersey
Ok so I'm building a high wattage stereo system and will be running dual batteries and high output alternator. I'll be doing this to not only feed the amps all the power they can get but also to keep the headlights from dimming when the subs hit. In the course of the build ive noticed that no matter what I do I can't get my voltage above 13.8 volts with any consistency which sucks since the higher the voltage the more power I can get out of the amps. In the spirit of feeding the amps all I can how can I go about fixing this? I know right now the maximum voltage is controlled by the computer. Is there any way to run an internal regulated alternator to feed the batteries that won't cause any issues with the computer and is there an alternator out there that will actually fit/bolt up that will achieve this??? Sorry for the long post but I wanted to lay it all out and get all the question out in a way that makes sense lol. Let me know what u think and if possible towards any threads that might help. Not just looking for a Durango swap thread, that will not fix it. Thx.
 
Most alternators int/ext regulated still maintain about the same voltage to the batteries themselves! I would consider a high out alt along with a dedicated battery!
 
That's not true. With an internally regulated alternator voltages run anywhere btw 14.4-15v depending on how it's setup internally. I'm looking to get my voltage up to at least 14.4. That's if I can get this figured out. I already have an H0 alt and 2 batteries.
 
You might 'fool' the ECM into thinking the alternator's output voltage is low by adding a resistor to the ECM's sense wire.
This should cause the ECM to increase the field wire voltage, resulting in a higher alternator output.
The other choice is to run an external, adjustable regulator.

As someone who has worked around heavy equipment and jet aircraft his whole carrier, hearing loss is a not a lot of fun.
With a stereo that needs this much power, you are well on your way.
The good news is hearing aids are much smaller today. The bad news is that they still suck.
 
Why put this much effort into being a public nuisance?
 
Ok so alternator with external regulator. What are the chances of finding one that actually bolts up to the jeep bracketry or would I use the stock/HO alternator and add a separate regulator to control it? And would that send the computer haywire? And second inline resistor. How would I go about finding the correct resistor to get the right voltage tho? Can someone tag 5-90?
 
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If you don't understand Ohm's Law, you are about to fry some expensive equipment...

Ohm's Law will answer most of your questions.
 
You are flirting with disaster. Anything from burnt components, blown fuses, burnt alternaors to overheating wires/fire and blown batteries.

Watts = voltage X Amps.

If you get up to around 15 volts (or excessive amp draw) the battery is likely to overheat. One reason they put a battery temperature sensor in there is to prevent this.

Amplifiers are designed to up the power, pumping more volts/amps to them is a poor way to substitute for one with good finals.

Jeep does make a 124 amp alternator for your year, my guess is this is about max with a safety margin.

Cleaning up after a blown battery is no fun at all, been there done that.

A dedicated heavy gauge wire and inline fuse directly from your battery to your amp and a matching dedicated ground wire, is about the best you are going to do.

http://www.pirate4x4.com/forum/jeep-non-hardcore/1105904-bypass-battery-temp-sensor.html

I haven't done the battery temp. sensor mod, after having a run away regulator (Delco) and my battery exploding, I've been happy to live with voltages within limits and trust the Jeep engineers ideas of the limits. In later model XJ's, the wiring is kind of anemic anyway.
 
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Here is what you're looking for I think. Keep the alternator that fits in your rig. just use this regulator. The complete kit comes with a resistor to keep the ECU thinking everything is ok. I don't have personal experience with the kit, but as soon as I have a few extra bucks to blow I'll be ordering one. It comes set to 14.3vdc I believe and it is adjustable. I wouldn't recommend going higher than 14.5 though. it'll probably get expensive replacing all your electronics.

https://alternatorparts.com/external-voltage-regulator-high-output-alternator-kit.html

I have to agree with BurntKat though...
burntkat said:
Why put this much effort into being a public nuisance?
Click to expand...
 
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LJRockstar said:
Here is what you're looking for I think. Keep the alternator that fits in your rig. just use this regulator. The complete kit comes with a resistor to keep the ECU thinking everything is ok. I don't have personal experience with the kit, but as soon as I have a few extra bucks to blow I'll be ordering one. It comes set to 14.3vdc I believe and it is adjustable. I wouldn't recommend going higher than 14.5 though. it'll probably get expensive replacing all your electronics.

https://alternatorparts.com/external-voltage-regulator-high-output-alternator-kit.html

I have to agree with BurntKat though...
Click to expand...

I have used that kit mentioned in this post fore some months then removed it because I did not like it.

With that POS battery temperature sensor, I could not get more than 13.5 volts first thing in the morning which gradually reduce itself the longer I drive. Later in the day it could be as low as 13.2 volts with a 165 AMP alternator that putout in the excess of 100 AMP at idle. The external regulator is adjustable and I was able to get a consistent 14.2 volts at all times. However, thee transition times of the regulator was not o t my liking. i.e. at idle, the lights would pulsate (for lack of a better term) high to low as if the regulator go on and off too slow.

8mud is onto something there. The battery temperature sensor at 80* (80 degrees) ambient temperature should read between 9 and 11 OHMs. I am yet to find one that is better than 9 OHM. Bear in mind the cooler the temperature the higher the OHM reading should be which in turn would cause the voltage to be higher. I have considered adding resistors to or across the sensor wires but am yet to do anything to it.

Keep in mind I live in Florida where we have seen a number of triple digit days every year. Add to that the power hungry dual cooling fans that love 14+ volts and the need to run the AC at full blast which together add a bit of anxiety looking at the dash volt meter. However, the alternator is more than capable of keeping everything running and the battery charger.

Some day I will try to get that 11 OHMs on the battery temperature sensor.
 
LJRockstar said:
Here is what you're looking for I think. Keep the alternator that fits in your rig. just use this regulator. The complete kit comes with a resistor to keep the ECU thinking everything is ok. I don't have personal experience with the kit, but as soon as I have a few extra bucks to blow I'll be ordering one. It comes set to 14.3vdc I believe and it is adjustable. I wouldn't recommend going higher than 14.5 though. it'll probably get expensive replacing all your electronics.

https://alternatorparts.com/external-voltage-regulator-high-output-alternator-kit.html

Thank you! I'm hoping this is what I'm looking for. I'm running 2 agm batteries specifically designed for this application so heat should not be an issue, they will run up to 16 bolts all day but I'm just looking to get 14.4 volts like most regular cars except my shitty externally regulated jeep. I'm also running a 250 amp alternator already as mentioned with no issues, except the computer is not letting me get more than 13.8 amps out of it. I also have upgraded all the primary power wires and grounds with 4 gauge wire with the exception of the amplifier feed wire and grounds and the alternator to battery feed and ground with 1/0 as per amplifier manufacturer recommendation. Thanks again for the help and not giving me a hard time lol. .
Click to expand...
 
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techno1154 said:
The battery temperature sensor at 80* (80 degrees) ambient temperature should read between 9 and 11 OHMs. I am yet to find one that is better than 9 OHM. Bear in mind the cooler the temperature the higher the OHM reading should be which in turn would cause the voltage to be higher.
...

Some day I will try to get that 11 OHMs on the battery temperature sensor.
Click to expand...

I bet that is what was going on here:


BatteryTempSens3OPT.jpg



The P.O. seemed to think a stereo was top priority. I have gotten rid of all that dead weight.
 
The difference between 13.8 volts and 14.4 volts is less than 5 percent. The only reason to use more volts is to push more amps.

On my 96 I had 600 watts of lighting (around 50 amps) with a 117 amp alternator. I was doing game counts (census) back in the days before LED and affordable thermal scopes. My issue was low engine speed and the alternator not putting out anywhere near advertised amps at lower RPM's. My solution was to swap to a smaller alternator pulley, which gave me a 15% boost.

What I'm saying here is advertised amp output may be RPM dependent. And 5% more voltage is unlikely to help a lot.
 
250 amp alternator comes with a smaller pulley. It's a good 25% smaller if not more. But again I can't get full use of that because of the computer essentially **** blocking me lol. I'm definitely gonna look into that adjustable external regulator in the morning, I'll call them n get the real scoop and report back. If it looks like a good deal and it'll do what I need it to I'm gonna go for it and try it out.
 
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The issue with voltage when it comes to car audio is every time the bass hits it drains the battery a little bit at a time. I have a digital voltage meter that plugs into the cigarette lighter to monitor voltage level so the higher I can get it to begin with(within reason) the longer I can play it at competition level before I have to stop and let the batteries recover so every little bit helps, you know what I'm saying? Even if it is just 5%.
 
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robsjeepxj said:
The issue with voltage when it comes to car audio is every time the bass hits it drains the battery a little bit at a time. I have a digital voltage meter that plugs into the cigarette lighter to monitor voltage level so the higher I can get it to begin with(within reason) the longer I can play it at competition level before I have to stop and let the batteries recover so every little bit helps, you know what I'm saying? Even if it is just 5%.
Click to expand...

Much bigger alternator, high idle speed, more batteries, ear plugs.
 
The alternator case was actually a little bigger lol. I had to grind the bracket a decent amount to get it to bolt up per instructions. I think it started out as a Durango 160 amp then they put the smaller pulley on it to bump it up to 250 but that's just my guess. When I'm running it at high volume I stand outside the jeep and control it via Bluetooth on my phone ;)
 
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That's another issue you can only bolt so big an alternator to the stock bracketry and it's not very generous to start with. Someone may make a custom bracket to do so but I'm not aware of any at this point.
 
I have just noticed your profile picture. My jeep is silver too lol. Just got it repainted today actually. She's looking all pretty and shiny as new I'm loving it. Soon as I get all the parts cleaned up and painted I'm gonna put the 6.5" lift and 35s from my old cherokee that unfortunately died a rusty death :(. Her spirit will rise again tho with this new jeep, can't wait to be riding high in the saddle again.
 
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