1st ever check engine light & electical fade

The value of “free advice” cannot be measured. Maybe sharing knowledge…showing someone “how to fish” and turning them in the direction towards self-sufficiency, is just what America used to be about…should still be about.

Happy New Year All!

Hope one of you has one more pearl of advice as I’ve gotten myself into a messier mess.

Since car could not be moved easily, my mechanic neighbor brought over his testing equipment and said I’d definitely need an alternator. I gave him cash for a rebuilt at AutoZone. He charged the battery off his car and so my battery is OK for a bit…but car has a short. He has asthma and the cold is too much for him now so he gave me back the key, I paid him for work so far and he told me not to start car because of short.

How long can this car sit, without being started at least, till I start my next job and can get it to a reputable shop? I hope it’s not curtains yet.

It’s not clear. Did your neighbor change the alternator?
Neighbor says that there is a short. I’m not so sure. Remember code 41, “Charging system has excess, or, no field current”. With either condition, the alternator will not send adequate (or, any) charge current, and voltage, to the battery.
My wiring diagram is undependable; but, this is what I see: the large black/gray wire goes from the battery positive post, through a fusible link, and connects to the alternator (probably by a nut). That wire, at the alternator (with the engine off), should be the same voltage as the battery. With the engine running, the voltage should be 13 1/2 to 14 1/2 volts at the battery terminal.
With the electrical connector disconnected from the alternator, the ignition switch ON, the wire (dark green/dark blue(?)) from the ASD Relay (Automatic Shut Down) should carry near the battery voltage (1/2 volt less permitted(?)). I think this is the “field current wire”.
The other wire (color(?)) should be the voltage output control wire from the ECM; IF the alternator does NOT have an internal regulator.
To recap the voltage checks: Turn the ignition switch ON. Measure the voltage at all the wires (connector disconnected from the alternator). The voltage on two wires should be same (near-same) as the battery. The black wire goes to ground. The voltage on the wire from the ECM, probably zero.
Reconnect wires to the alternator, run engine, measure the voltage at the battery. If it’s not at least 13 1/2 volts, the battery is not being charged.

As I said before, the power wire from the ASD relay may be the “field current” wire. The horn relay is probably identical to the ASD relay. Swap the two relays; then, check for charging voltage at the battery post (13 1/2 to 14 1/2 volts) with the engine running.Results?

commonosence i never new you could find a code.without a code reader.great advice.saves a trip to the mechanic and money. dominic

It sounds to me like the voltage regulator AKA Field Driver Circuit in the Powertrain Control module is defective, or has a broken, or bad wire/connector.

If swapping the ASD relay like hellokit suggested fails to fix the problem then it may be time to take it to a shop for diagnosis. The only other part to swap for diagnose is the PCM, and that is too costly of a part to be guessing at.

I would start checking around for a used/salvaged PCM if it turns out to be the problem.

Sundance93,
You gotta do some voltage checks on the alternator. There’s no other way. Remember that all the wires (except the black ground wire) are hot (have voltage). Disconnect the wires from the back of the alternator. Turn the ignition key to RUN. Measure the voltage on the black/gray wire. It should be the same as the battery. Measure the dark/blue wire. It should be 10 plus volts (from the ignition switch). Measure the dark green wire (from the ECM). With the factory scan tool (DRB II) you should see the voltage vary from 0 to 12+ in 1 to 4 seconds. With a hand held multimeter, I don’t know. Let us know the results. And, let us know if this is a 2.2L engine, or, a 440 c.i. six-pack. OK?

Hellokit,

I hope you are still out there for this late reply…forgive me…I didn’t mean to be two months rude. You went all out with your detailed info. Thank you. I’ve been overwheomed with my end of the economy, jobs, etc., I just left the car in the lot and have only now gotten back to the topic and will have $$$ in a week for the fix.

Truthfully, your knowledge is way over my head. My neighbor put in a newly rebuilt alternator and thinks I have a 2.2L. He told me not to start car and he would come back when the weather breaks. I don’t feel comfortable with continuing the repair with him (he hasn’t knocked on my door again to continue it either.)

I think the car needs an Auto Electric Guy with all the know how and equipment in one place.

I WILL write back.