battery voltage drop at idle

[88beater]

94 2.3L Manual Ranger...I've noticed that when I'm idling or coming to a stop...intermittently...the battery voltage will drop 2-3 volts it seems...give it some gas and it jumps back up to normal. I'm thinking there is a problem with the IAC solenoid or valve...I'm no expert when it comes to electrical problems. Anyone have a similar issue or know what the problem may be?

Thanks in advance guys!
-Josh

[freeclimber]

Are you basing your info on the voltage guage in the instrument panel?
Sounds like your truck is trying to stall when coming to a stop.
Is your engine light on?
A guess would be your EGR or EGR control sensor.

[88beater]

Yes, I am basing the voltage drop on the instument panel...it is a definite drop...not like the flicker when you turn the blower on high or anything. The needle goes from one side to the other!

Any way to check the EGR or EGR control sensor?

[package123]

have you checked the alternator there are usually three diodes in them and when one blows the output drops therefore when at idle (lower rpm) the needle will drop because you are put out less amperage and voltage and then when you give it some gas even though the alternator is putting out less it can keep up with the present load u can do a quick check by putting a volt meter on it and see how far it dips down or just take it out and take it to the auto parts store and let them load test it i have a buddy that owns a starter and alternator rebuild shop and he fixed my wifes on her jeep and this was the exact symptoms he said jumping cars, loud stereos etc are usually the cause of a alternator diode going bye bye he also said once one goes the remaining 2 will go faster for the load will be heavier hope this helps mike

[freeclimber]

If you don't give any gas, does it stall or does it continue to run with the guage reading low?
If the problem only happens sometimes, then I doubt it's a hard fault like a bad diode.
You need to do a wiggle test!

[88beater]

I have replaced the alternator...probably about a year or so ago--maybe not even that long. Do you think it would be the alternator if it happens very intermittently. It does happen a lot more in the rain in seems though.

In response to freeclimber, I've only had it stall on me once. The voltage will usually increase on its own back to normal, say when I come to a stop and have my foot on the brake and can't easily give it some gas. I most likely say that the meter drops down for a second or two before recovering. I guess I've never noticed it just stay at a low reading.

Any idea what I would wiggle? Thanks.