Problem With Vehicle

Ok ok, so maybe it isn't a Tacoma, or a even a Toyota. My wife has an Isuzu Rodeo pushing 200,000 Miles and today she said she was letting it warm up this morning and all of a sudden the lights dimmed and the car slowly died. But she was able to start it right back up. So whats the issue?

 

alternator?

 

Battery? Does it crank?

 

^ my best guess. Second would be the battery but definitely sounds like an alternator to me

 

I'm not so sure there, guys.

If it's just the alternator, the car will run off the battery until the battery is dead, right?

Yet it started right up. So it's an intermittent problem.

I think I might start my search sply looking for a loose and/or badly corroded cable or connection.

 

Yea, I've had a bad alternator before on a car and it wouldn't start back up after it died. I just don't know what it is. I want to make this car last another year then we will buy her a new car. This car is a 2002 V6 Isuzu Rodeo LS.

 

I'm thinking the lights dimming might be a symptom of the RPMS dropping to under 500 as the engine's dying - not a symptom of the underlying problem.

That would only happen if the battery was marginal - but that's certainly a possibility on a 2002.

Did it throw a code?

Good luck man - intermittent gremlins are the worst. Last two times I've gotten rid of a car it was because of intermittent problems that couldn't be reproduced regularly enough to successfully fix them.

 

After rebuilding quite a few alternators and building 300amp ones, there in 3 things that can cause the problem. If the voltage regulator is going bad you will see this problem, take a volt meter and watch it, should read 12.6 befor start up, while running 13.6 (+.3 - .4) If you notice the voltage jumping form 12.5 to 13.6 then the voltage reg is bad. If you rev the motor and the voltage jumps back to 13.6 then the winding or the brushes are bad. if it is reading above 14V then the diodes in the rectifier is bad. dont check any of this at the BATT, check on the stud at the back of the alternator. you can also unplug the 3 wire pulg the goes into the voltage reg and if nothing changes the alternator is bad.

 

Sounds more to me like a loose terminal somewhere. If the alternator was bad, surely you would have had a completely dead battery for the car to die on the road, but you started it right back up. Thats not to say though, that something could be shorting out internally, but I've never seen it.

Look over everything you can, look for loose connections, check your battery posts, follow the wires from the battery to the fuse box and to the chassis.

 

that is the obvious, and i would figure that OP would check that before posting. If there is no lose connections, and everything is good with the ALT, there is a fuseable connection between the ALT and starter (ford) some are between ALT and BATT, check that. i had an issued when i built my 300 amp ALT last year on my ranger, when i used the winch and 10 lights, i cooked the link and built a 2/0 gauge wire fuse with 285 amp block. that truck made me gain the experence with electural gremlens.

A good multipy meter with have a conanuity tester. use that all over the place.

 

Before I left this morning I started up the car to let it idle for a bit and it actually ran down real low in the RPMs and the lights dimmed. It didnt die though and eventually the RPMs came back up. It only does this when it is first started and the auto shop tested the battery, starter, and alternator yesterday and they said it's all working good.

 

Maybe an issue with the idle air motor if it has one. I had a Dakota that did that when it was cold. Sometimes it would stall, sometimes just idle real low. Changed the IAC and it went away.

 

What RPMs? V6 should idle around 700rpm iirc

 

this...the IAC went bad on my dakota and i would see it rpms jump all over the place. plus/minus 700 rpm