hi everyone, i have a 01 ram 1500 sport 2wd 5.9L and just last night it started to dim the headlights when im stopped at a light or stop sign. the voltmeter drops but as soon as i give it gas it jumps right back to normal levels. it dosnt sputter or back fire but i did notice a slight squeal coming from the motor when i give it gas and it charges back up. You think this might be the battery??? it is really cold over here right now to.



Thank you,

Mike

 

is the batt older tha three years? what is its voltage with the engine off? there are a couple threads about the regulator. it may be time for a external.

 

Alternator is going bad...once the truck is started, it runs off electrical power from the alternator. Our trucks are very sensitive to voltage changes so if your battery is bad or has been run dead, the truck will try to shut off the engine or will run terribly until the alternator (assuming it's good) has a chance to charge it back up. In your case, your alternator only charges when the engine's rpms increase...your battery is likely still ok, but you need to change the alternator.

 

+1 on the bad generator. Usually when the battery is shot the truck wont idle. You have to give it gas to keep it running. Id check the wiring first to make sure it isnt damage externally or internally (excessive resistence, cracked insulation, frayed or broken wires, ect. ect.)... You can probably find a rebuild kit for the generator, but im not sure if a rebuild would be cost effective. Might be cheaper to just get a new generator.

 

so i brought my alternator and had it tested and it tested good but the diode came up n/a on the machine. No clue what that means and the guy was stumped as well. Is this something that will continue to happen or will it just quit out on me one day. Every time it does it and i give it gas the voltmeter does jump right back up but as soon as i come to a stop it does dim again.

 

Im assuming that when the machine says diode its referring to the diode trio which is used to rectify the ac voltage output of the generator to dc voltage. I have no idea what it means with n/a... I've only used vat-40s to test charging systems. Did the engine have to be revved up for the test. generators can sometimes pass a regular charge test but not be able to produce the required voltage at heavy loads. Was the test a full field test? This still sounds like a charging problem to me. Did you check the wiring?

 

i brought it to my local parts store and they threw it on a machine that said everything was fine but when the ticket printed up it just said under the diode N/A. he ran it at least five times and came up with the same results. its really mind blowing to everyone ive asked. i think im gonna grab a used alternator from my parts guy and give it a whirl and have them test it to see if it comes up with the diode thing.

 

Sounds like my truck when my old battery went to crap, replace your battery is my suggestion