BOSSFC

iTrader: (2)

Idiot lights were coming on intermittently so I replaced the alternator that was still under lifetime warranty and when it was checked at the shop it was low on power. This alternator was only put on this September. When I installed the new alternator today it started up and voltage went to 14 so I let it idle and went inside for about ten minutes, when I came out it was bogging down in idle and the idiot lights were all going on and off. They would stay on then when the idle would bog down go off. These idiot lights also went off when i pressed the brakes. The idiot lights do all come on with the key at ON. When the engine starts they go off and then come back on and behave as stated before. The voltage meter is inconsistent around 12 volts going up and down slowly. I am completely stumped can anyone help?

ericgrau

iTrader: (1)

If the voltage is changing rapidly such that you see the needle moving, you probably have a bad or weak battery. Slower is probably the alt. But since it started up fine I can't be sure, could be an intermittent problem or a short in the alternator. Or a bad replacement alternator could have fried your battery too. An auto parts shops will test both the alternator and battery for free, though intermittent problems might sometimes test as fine. It's not uncommon to get multiple bad reman alternators before getting a good one (or the first one might be fine, it's a gamble); all that lifetime warranty means is they have freedom to give you shoddy remans. Might as well make it two lifetimes since the problems always arise within the first few months (or weeks or days or minutes) anyway. Unfortunately if they did blow your battery the warranty only covers the alt. If you know a reputable alternator shop you could tell off the auto parts store until they give you a refund then go there (b/c technically you can't get a refund). Or upgrade to an alternator from an FD or another car. Otherwise your best bet is to keep retrying until you get something that lasts. Fortunately it's easy as pie to swap alts and batteries. Happy swapping.

BOSSFC

iTrader: (2)

Just tested the battery and alt both tested as fine at the shop, not in car. I am going to keep trying, but could anything else cause a problem like this instead of the actual battery or alternator?

satch

iTrader: (1)

Make sure the TPS is set properly as to 1 volt when the car has been completely warmed up and try to get the engine idle from fluctuating and see if this fixes the electrical problem.

BOSSFC

iTrader: (2)

I will do the TPS tomorrow but I took it for a drive today and have some more symptoms.

The idiot lights will go off at higher rpms for a moment then return.
At WOT it will appear to be fighting to charge, idiot lights going on then off then on.
When voltage is getting very low it will idle high ~1500 RPM.
When certain electricals are first triggered i.e. turn signals, idiot lights will go off and car will begin to charge.

BOSSFC

iTrader: (2)

only vehicle necessity bump

satch

iTrader: (1)

On the back of the alternator is a two wire plug. Check for battery voltage on the B/W wire w/key to off and the plug can be disconnected for testing purposes. With key to on, test the voltage on the W/B wire but the plug needs to be connected to the alternator so either back probe if possible and if not then ***** the W/B wire with a pin and check for voltage and it should read 1 to 3 volts. If you could get the car to act improperly when it is idling then test the voltage on the B/W wire and do the same for the W/B wire w/plug connected for both tests.

BOSSFC

iTrader: (2)

TPS did not help.

did the electrical tests:
While not running-
W/Key to on- WB read 1v to 1.1v
BW read same voltage as battery w/ key off

W/ car running and idiot lights showing problem
WB reads 1 to 1.1 v
BW reads same as battery

W/ car running and idiot lights not showing problem
WB reads 11 to 12v
BW same as battery

BOSSFC

iTrader: (2)

bump

satch

iTrader: (1)

This should not be occuring. There are only two possible causes for such a reading. Either the W/B wire is grounded out against something intermittently or there lies a problem within the alternator itself and the latter problem is more likely.

BOSSFC

iTrader: (2)

Got another alternator from the lifetime warranty and it has been running fine all weekend, another example of an alternator testing fine in store and not running in car. Thanks for the help.