alternator compatability

[Dave]

Seems the alternator on my 90 325i may be going bad.

I have in my parts bin an unused Bosch rebuilt alternator for an early e engine car. It seems the main difference is the e alternator has a rubberized mount and a ground strap to the case. Otherwise, it looks like this might work.

Any reason I should NOT use this alternator in the I?

[MR 325]

I've never swapped an earlier alt on to a later engine but I "think" as long as you hook up that external ground everything should work. Sorry for the typical R3V response but a chance of help is better than none at all. ;)

[TG Goose]

it will work, but lower amperage.

[Dave]

it will work, but lower amperage.

thanks.

[Gregs///M]

Ya, you might find the lower amperage will cause interior and headlight dimming, less stable electronics. However, since you already have it, no hard in trying it.

[MR 325]

It seems to me that lower amperage shouldn't be that big of a deal considering the other alternator is still factory from an E30 M20 car.

[Mtriple]

Not an issue. I found out the hard way that you need to ground the case. I spent the better part of a friday two weeks ago trying to figure out why my car wouldnt start. Added the ground to the case on the alternator and viola, everything is peachy.

Can anyone explain why my alternator not being grounded would play into the car not starting? Battery was showing a solid 12.5 volts at rest.

[Denny]

it will work, but lower amperage.

I dont think this is true. I have the I and E versions at home and the i 70A and the E is 90A.

I was researching as I needed one with more A to drive my EPS (I found a manufacturer that rebuilds them to 130A for 150$ total no core :)

[TG Goose]

I was mistaken, eta and i alts should both be 90A, my 1984 M10 was 70 amp.

[Dave]

Made a strap out of 8 gauge wire - we are good to go!!!