thanks!!! I will hopefully get to it on my next 2 days off. We're in the middle of a snowstorm right now....and i got no garage.....thats my luck though...if i cant find the problem could i just toggle switch a wire from the battery and get it to charge constantly? i need this car to get me to and from work.

 

Or just disconnect the wire - after verifying WHICH wire it is from the wiring drawings.

When that wire is open-circuit, the alternator should charge - IF that's the actual problem causing your alternator to not charge.

 

k guys thanks you's all so much for all the imput. You's have no clue how much i appreciate it. I tried cutting the C wire wich is wht/grn didnt work....and at the same time also found out i'm only getting 4.98v comming into the wht/rd wire.......now the ? is does anyone think its the ELD or ECU?

 

Voltage regulator is #19 in this picture. Brush holder is #3. Check whether the brushes are simply worn out & only intermittently touching the contacts on the rotor.

Look for burned-looking components on anything in there. Diode rectifier is #8 but they seem sorta robust - don't seem like a real common failure.

Since you cut the C wire, check it with a multi-meter set to measure resistance to ground. The C wire should NOT have any continuity to ground.

I'm not real sure how to test the other wires at the alternator. There has to be an excitation supply but that might be completely inside the alternator (created by the regulator).

 

If it was the ELD or ECU, I think you'd throw a check-engine light.

Measuring resistance to ground will test if that C wire is pinched or cut & grounded somewhere between alternator & ECU.

I guess having thought about it a few seconds, most people would not test for a burned-out rectifier. They'd hand the alternator to the guy at the parts counter who would test the whole alternator. A bad rectifier would cause the alternator to test bad. Worn-out brushes would cause the alternator to test bad. etc...

 

Hey Umm well its a brand new alternator thats been bench tested. everything is 100% with the alt. It's not an alternator problem and well i am throwing a CEL. I took the code and got the p0141 for my O2. and to be honest i only got the CEL after this problem arose.

 

Sorry about the brand-new alternator. After reading 100 threads, I don't always go back to the beginning of each one. No other CEL codes like P1297 or P1298 (those are for ELD)?

Kinda stumped...

 

nope no other codes at all...i have a black and decker odb2 reader. I keep checking after everytime it relights. i too am stumped.....i'm leaning towards ECU though. All my grounds in the engine bay are brand new. so its not a ground issue. Changed the alt.....put a new battery.....
I thank you for you input so far though Jim

 

You cut the wht/grn wire, so the wht/red must be the L wire for the charge light and on to battery. Voltage on this would show a drop across the Alternator light, so voltage could be OK.

The blk/yel wire should have 12V directly from battery. What is voltage at the alternator for the blk/yel wire? It's call the IG wire on my wiring diagram.

Have you check continuity of the heavy (wht or blk) wire from the alternator to the underhood fuse box (battery bus)? This should also have 12V at the alternator.

good luck

 

Was wondering if anyone had an ECU layin around that they would sell
I need one of the following models
Ident: 37820 P0B A70
Ident: 37820 P0J 305
Ident: 37820 P0J L51
Ident: 37820 P0J L60