ian_s

Hi,
Could anybody tell me if the third gen starter motor uses a negative or a positive feed?

Thanks

Ian

911GT2

I don't know the difference. What makes it a negative versus a positive feed?

FormerPorscheGuy

Positive, but don't hold me to that.

PVerdieck

Positive, I think. One of the tricks in some battery relocations is to run the positive to the starter.

spurvo

Definately positive feed. The plate that the battery post mounts to has a big damn wire crimped into it. That's the starter power feed. It is unfused.

DamonB

Any car with a negative grounding system is going to feed positive power to the starter motor.

Hyperite

Damon = Smart. I = dumb for finding out the easy way when I was taking it off that it is positive feed (read: SPARKS!)

ian_s

Thanks for the reply's. I was sold a reconditioned starter motor, and it had been rebuilt with a negative feed. Managed to bump start the car and it ran like crap untill it eventually conked out. Anybody know what running with a negative feed to your starter motor can do to your car to cause that?

Hyperite

Well, you should've noticed some really really big sparks when you tried to install it, since basically the whole starter would've been a positive lead. If not, and it's a negative ground and negative feed, well...the rebuilder wasn't very smart huh. You'd be as effective trying to start it by saying "c'mon baby! show me the money!" as turning the key to the starter position.

InsaneGideon

Haha... That brings back memories.

My dad & I were replacing the starter on my first car, years ago. I said "Dad, shouldn't we disconnect the battery first?" He says something to the effect of "Nah what could happen?" After just connecting the positive lead to the starter, a WOT switch's ground wire slipped through several obsticles (intake/hoses), and the INSULATED female spade plug hit the positive bolt on the starter at just the right angle. Smoke suddenly appeared everywhere around the engine bay. It fried nearly the whole damn engine harness, which I had to fix myself.

Needless to say, I learned a lot about automotive electrical that month.

Sparkey

I have an aftermarket starter that I dont need if you want it its been cranked maybe a dozen times. Yours if you want it just make an offer.

ian_s

thanks for the offer but I have a new one now and car is running sweet again. Just want to know if having the wrong type of starter motor can cause your car to run crap like that?

DamonB

It's always funny when it happens to someone else, right?

Automotive Electrics Rule #1: Never let the smoke out of the electrical system

InsaneGideon

Yea, it is pretty funny! :P: My HS electronics teacher used to laugh his *** off at some fairly serious explosions & fires in class. We laughed too. I loved that class. Luckily, no body was maimed that year.


Sad part was, I was well aware of Rule #1 at the time. The learning experience was accrued through fixing the aftermath. A new wire harness cost as much as the entire car.