16 volt charging rate too high?
 

my charging system quit working, so i then put a rebuilt alternator in and that dint fix it. then come to find out the voltage regulator on my truck is built into the pcm...(stupid)...so i bypassed the pcm by wiring up a new mopar external voltage regulator, now its charging rate is around 15.5 to 16 volts and is not steady. the gauge and running lights bounce up and down. what is the problem?

16 volt charging rate too high?
 

Sounds like a bad ground somewhere. Kinda doing the same thing a sulfated battery would cause. The regulator increases alternator voltage trying to push the current through a bad connection. Should charge around 13.7-14 sumthing. Shouldn't be higher than 14.6 tho.


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Usually comes down to 2 possibilities. The first is bad connections, usually grounds. There are a lot of both in the circuit. The second is how the external regulator was wired in. You need to completely disconnect the 2 wires from the pcm. Best place is at the pcm. Then use the 2 wires to the external. MAKE SURE THE EXTERNAL HAS A GOOD GROUND. Sand the pant off around the screw holes so it gets a solid contact.

I had a 93 once that done the same thing 15.5 to 16 will not hurt anything I drove mine for a year like that and then I got rid of it and it never bothered anything but the lights do get kind of anoying.On my 92 I had the same problem a few months ago with the bouncing charge but my regulater was fine but it wound up being a bad fuseable link not making good connection after I changed it I havent had anymore problems I also replaced grounds and it didnt help.I dont know if this will help or not but I hope it does good luck.

i've ran into a bad regulator causing these issues too. if i remember correctly i ordered a mopar performance one from summit racing and it solved the advance auto parts brand issues.

You have a GOOD ground at the regulator?

I'm gonna try the ground at the regulator and ill get to ya thanks everyone

Any update?

I tried a ground from the regulator to the engine block and still had the same results. I dont know what to do:argh:

Did u check the fuseable link its the little white one that is by its self.

i had the same trouble i end up hiring some one to fix it for me and come to find out it was a bad ground. double check all you wiring that you did.

Would a 89 have a fuseable link??? Cause my truck has had brand new alternators and voltage regulators all the time over the last year and a half. Now about a week and a half ago the battery was dead so I jumped the truck and drove it for about fourty five minutes and it started chargin at 15.3 to 15.6 volts and boiled over the brand new battery. But now the battery wont charge and at the back of the alternator its only putting out less than ten volts:argh:

I'm real glad u guys on here that r so smart can help a guy out when its asked

So the ground on these voltage regulators is established where the regulator is bolted to? or do yo have to run a wire for the ground?????

Regulator is bad, very bad, it is likely the alternator is out too now. :(

solve your problems and get an alternator with a regulator built in

X2, I should have listened to my engineer friend and done this as well. :)

Hook up your external Regulator just like the old mopar cars, and disconnect the 2 wires as you were told running to the PCM. I had to track this down about 2 years ago.
The only weak link on these trucks are the electrical system.
I took all those fusible links outta the system on the drivers side fender, put in 2 heavy duty fuse blocks.
I balanced the electrical load between those 2 fuse blocks, as I'm running a 15,000# Winch, 8 Hi Output lights pointing forward, 6 pointed rearward, low profile Emergency lite bar up top between all those floodlights, battery isolater with 2- 1000 amp Interstates under the flatbed powering a 6000 watt Power Inverter....
The cops hate the flickering lights too....they will give you a ticket for that, or try to.

I Drove from Shreveport, La. to Ca. without my alternator charging, I couldn't turn off my motor cause my battery was dead, I'd just change out one of my fully charger batterys outta the back.
I have my truck now set up so if I loose my charging system, My fuel cutoff solenoid is removed, I now shutdown with a cable, I can flip a cpuple of switches on my dash and my elect. system can run off my rear batterys, if needed.

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Oh, by-the-way, ALWAYS carry a extra regulator on ya....