Alternator Woes

[Fader]

Hello TDR.

I am experiencing what seems like an odd issue with the alternator on my '97 Ram.

Yesterday my 'gen' light illuminated on the dash & the factory voltage gauge read 16+ volts.

The light would go off & the gauge would return to 14 volts +/- as I stopped accelerating.

I got home, parked it, & got out my multimeter.

While running in neutral I was getting 13.7 volts at idle. I experienced a very minimal (.2 volts) increase as I moved the throttle linkage myself from under the hood.

I connected my power probe under the hood & routed the controller into the pickup with me so that I could monitor the voltage.
I can press the accelerator down in neutral & voltage doesn't seem to increase...but if I am in gear & accelerate the voltage does increase to 16+ volts...the same as is indicated on the factory gauge.

I was prepared to replace the alternator but now I'm wondering if there isn't something else at play?

Any guidance or helpful suggestions are appreciated.

 

[Iron Duke II]

Hello TDR.

I am experiencing what seems like an odd issue with the alternator on my '97 Ram.

Yesterday my 'gen' light illuminated on the dash & the factory voltage gauge read 16+ volts.

The light would go off & the gauge would return to 14 volts +/- as I stopped accelerating.

I got home, parked it, & got out my multimeter.

While running in neutral I was getting 13.7 volts at idle. I experienced a very minimal (.2 volts) increase as I moved the throttle linkage myself from under the hood.

I connected my power probe under the hood & routed the controller into the pickup with me so that I could monitor the voltage.
I can press the accelerator down in neutral & voltage doesn't seem to increase...but if I am in gear & accelerate the voltage does increase to 16+ volts...the same as is indicated on the factory gauge.

I was prepared to replace the alternator but now I'm wondering if there isn't something else at play?

Any guidance or helpful suggestions are appreciated.

I'm confident someone on the forum will have experienced this issue and come up with a solution.
My initial thought went to a voltage regulator.
Mr. Gould see below may be able to suggest a resolution over the phone.
GOULD GEAR & ELECTRIC INC.
MURPHY, NORTH CAROLINA
(828)644-1900
https://www.fixinrams.com/

 

[BigPapa]

Where are you checking voltage at?

 

[Fader]

Thank you Iron Duke..I will give him a shout.

Big Papa, I checked it at both of the batteries as well as the terminals on the alternator.

That reminds me that I wanted to research further the alternator setup... never had a vehicle with this setup of two terminals like this 97 has.

One of the two had the correct voltage while the other had a significantly lower voltage.

I'm going to look closer this evening & better document what readings I get where.

 

[GAmes]

Did you check the battery temp sensor that is under the left battery? Specs and a description of it's function are in the FSM.

If you didn't disconnect the positive cable that goes above the radiator you will get the same reading on both batteries.

 

[BigPapa]

If you didn't disconnect the positive cable that goes above the radiator you will get the same reading on both batteries.

This was what I was getting at. The crossover cable that ties the positive battery posts together has been getting a lot of attention here on TDR lately.

 

[Fader]

Thank you guys... I am still going to investigate that temp sensor but I began reading a few forum posts on that crossover cable.

I looked closer at mine & it had a relatively small amount of corrosion where it connected to the main positive terminal on the drivers side.

I cleaned it up some & the issue went away for today...I was able to haul my step daughters furniture for her & that was nice to get done.

The hydraboost just went out on my Cummins swapped c30 so it isn't going anywhere right now.

I hadn't looked really close at that terminal just yet since I has just pulled everything apart & thoroughly cleaned every terminal just a few months ago.

The crossover cable looked good externally but I am going to replace it as well.

I definitely appreciate the point in the right direction.

 

[Ozymandias]

Its not only that wire, the ground wires are also suspicious.

 

[Fader]

Its not only that wire, the ground wires are also suspicious.

Absolutely. They both appear really good on the battery side but I will inspect those further &/or replace them as well.