1997 850 T5 Alternator dying soon!

Megaromania · Post by **Megaromania** » 28 Jan 2015, 07:11

Hey guys
I am having a problem with my car its dying on my on idle from time to time and i dunno what to do !
i changed the pcv last month and fuel filter because i suspected its clogged
and if i want to change the alternator what brand should i go with?
is the autozone brand ok or should i stick with Bosch ?

Thanks!

hanzbe420 · Post by **hanzbe420** » 28 Jan 2015, 07:17

you sure its not the battery? did you have it checked?

Post by **erikv11** » 28 Jan 2015, 07:53

Agreed. As part of that check: clean up as many of the electrical connections as you can: cables where they connect to the battery, grounds where they connect to the frame. Do the cables get hot at the battery? That is a sign of a corroded/failing cable.

Herb Goltz · Post by **Herb Goltz** » 28 Jan 2015, 08:04

I think you need to make some measurements first before throwing parts at this. Get the battery load tested at AutoZone. Get a voltmeter and measure the voltage across the battery terminals at idle, then repeat it with the defrost, seat heaters and high beams on. Measure at the thick red wire on the alternator (ground on the intake manifold). As erikv11 said, check the battery cables for heat. Make voltage drop measurements on the pos, neg and B+ cables (search this site for good instructions). Cleaning connections is good too. Make sure your battery terminals are clean and tight.

If your alternator is implicated, consider replacing the voltage regulator/brush assembly (~$40) if the only problem is low output voltage (<13.7 VDC) at the thick red wire on the back of the alternator. Many rebuilts aren't that great.

Report back with your measurements and people here will help!

Post by **BEJinFbk** » 28 Jan 2015, 08:24

I agree with Herb - In fact, it may not be a low voltage problem at all.
There are a number of things that could cause the problem you describe.
Are you seeing a CEL? Is the car throwing any codes?

Post by **tryingbe** » 28 Jan 2015, 15:12

Buy a multimeter and measure the voltage, it's like $8 at harbor freight.

Post by **BEJinFbk** » 28 Jan 2015, 23:36

tryingbe wrote:Buy a multimeter and measure the voltage, it's like $8 at harbor freight.

This!
But again, keep an open mind.

Post by **cn90** » 29 Jan 2015, 08:31

Actually the multi-meter is free this week at Harbor Freight. See their weekly ad flyer.

Back to the original poster, check the "B" cable for corrosion.