Is my alternator going out?

[Sotarts]

After the car has been sitting undriven for a while (few hours, or overnight), after I start it, Check Engine, Radiator and Brake lights stay on for a while (dim) while the car idles. Power is being obviously drawn from the battery, since it stays at 12 volts. Basically, same symptoms of a dead alternator.

BUT, after the car has idled for 20, 30 seconds or a minute (lately), those lights completely shut off like nothing is wrong, car idles perfect, voltage goes up to normal 14+ and stays there for however long I drive, battery is being charged, etc... There are no drivability or any other issues otherwise whatsoever. If I don't drive the car for a while again, this happens again, every time. It's been happening for the past three weeks or so. Seems like it goes to normal function faster when weather is warmer.

ECU is fine. Does this with two different ECU's. There's no crazy wiring in my car. Everything else is peachy.

Is my alternator going out? Or some wire is loose/has dirty contacts and makes full contact after heating up???

Can someone WITH EXPERIENCE please reply? Thanks.

 

[luv2rallye]

Nearly worn out brushes in alternator will do that. After they heat up they start making better contact. Have them replaced.

 

[Defiant]

Yup, it's dying.

 

[evolvingGS-t]

It's going bad.

 

[Sotarts]

I guess it's time for a 90-amp alternator.

What would be a good source for a 90-amp (GVR4 spec, I guess. What other models from?) alternator besides dealership? I don't trust Murrays, PepBoys I don't trust either. I definitely don't trust some no-name shop, guy tried to screw me over with that last year...

 

[BUCK]

Make sure you have NO Power Steering Fluid leaks dripping on your Alt - that will kill the Voltage Regulator in a Heartbeat & can toast your ECU... If you haven't replace EVERY O Ring on your PS Pump you need to NOW.

I put it on Car Ramps & come from underneath so no need to remove Fan - It's still a PITA...

- I had my Bumper to Bumper guy look up the Highest Amp Mitsu Alternator that would fit a 1G:

- Max amperage 121 amps

- 100 amps at 3000rpm

- Max 1548 watts

- Manufacturer Ampere - Ampere P/N 21491

- Cost was about $150.00

- I run a 1 Farad Cap too with an El-Cheapo Battery that pushes a 500 Watt Sony Amp & head Unit no problems - no dimming, etc.

 

[JwUoNoG]

Question: If an alternator wasn't connected properly (loose belt, bad connection, etc), wouldn't it experience the same symptoms as a bad alternator?

 

[Sotarts]

Probably. Loose belt = no charge, but I guess it would have to slip the entire time until it warms up and everything catches spining again. Bad/dirty/corroded connections = definitely.

 

[luv2rallye]

And slipping the entire time normally would give a tell tale screech and wear out the belt (obvious signs when looked at). But definately check the tightness as a loose belt will tighten up as it gets hot. Bad/dirty/corroded connections look like a bad alt. but usually they stay there (don't go away with time or speed).

 

[lhhc]

So, this kinda has to relate to the alternator. Mine was going out, so I had to replace it. Inorder to get it out I had to remove the PS pump. When I put it all back together, the belt thats running the PS pump, won't spin, or move or whatever. the alternator belt is fine, but its the PS pump that won't.....go. When I took the PS and alternator belts off, they shouldn't have to be put back on exactally how it was taken off does it? I mean the pulleys on the motor don't have to be in the same exact spot do they? I let the car idle for a few minutes before I realized the belt wasn't moving, and it started to smoke a little bit where the pulleys are on the motor......any help would be appreciated...

Thanks,
Joe
AIM - lhhc30
[email protected]

 

[luv2rallye]

No the spot doesn't matter. For a 2g: The PS pump bracket and alt. arm must be put on properly. And the pulley on the water pump that drives the alt. belt must not be put on backwards or the pulleys will line up a little off.