Hi torque starter install: Short circuit?
 

Yesterday I installed a IMI 101 Hi Torque starter on my 1978 911 SC.

Installed it as follows:
Thick black cable from battery + red cable from alternator attached to the single clamp, 2 yellow wires via piggyback attached the the single spade connector on the starter.

However, when I reattached the negative clamp on the battery, lot's of sparks and I almost melted the clamp to the battery post!?! As I'm not an expert, no idea how this is possible ... Any thoughts?

FYI: I re-installed the old starter to be sure the connections were ok and car started just fine ...

heh, that battery cable to the starter always has full voltage running thru it, you should disconnect the negative battery terminal before working on the starter. You're lucky it didn't shock you while working on it and you'll be lucky if you didn't fry some other part of your cars electrical system too.

BTW, I just installed the high torque starter on my car too, works great.

Of course the negative terminal was disconnected while working on the starter ...
It happened when I reconnected the battery terminal after I finished the installation of the starter!

And I'm pretty sure I didn't fry anything else otherwise the car wouldn't have started with the old starter.

It sounds like the starter my well have a short. Use a OHM meter check the positive terminal on the solenoid to the starter case and see if you have continuity if you do it's toast.

Dang that's messed up! Never heard of one just frying like that. Can you even test the solenoid->starter wire on the hi torque starter? If I remember right its wrapped up in a plastic casing eh?

All connections to the "starter" should be on the starter solenoid. Confirm?

If so, and current flows immediately upon connecting the ground battery cable, there's a short circuit in the starter or solenoid (assume ignition switch is OK). Remove and bench test, diagnose/repair or sublet the above to an electric shop or rebuilder. Alternately, remove, alert seller and return for inspection/replacement.

Sherwood

Photo might help, maybe there is an insulating washer or something missing on the positive terminal of your new starter. With the starter solenoid not operated, ie the starter just sitting there, you should have a very high resistance from that battery connection stud to earth. Sounds like yours is a direct short.

I always flash the neg connection momentarily onto the battery terminal after doing work like this just to check for massive short circuits. You often get a brief spark but not molten bits. Must have caused a few grey hairs.

I benchtested the starter with jumper cables and everything seems fine ...

So now I'm even more confused about what could have caused the short while the starter was installed?

Can you upload a photo of your starter motor and your vehicle connections to it?

Your bench test connections to a battery should be identical with the vehicle. How did you energize the solenoid on the bench?

In addition, if you have a multimeter, test for source voltage at the yellow ign. switch wire, at the connector to the solenoid. Should be zero volts at rest and 12 volts with the ignition at the crank position.

take the starter to advance and let them test it for.....freeeeeee.

solenoid could be in backwords. cant remember if the starter just runs or if you get arcs and sparks.
if not, your solenoid is shorted.

photo could help

try it without the 2 yellows if it is back in.

Based on your latest description, it sounds most likely that you somehow grounded one of the power cables during the first installation. Are you absolutely certain that you don't have a questionable section of insulation along either the cable from the battery or to the alternator?

The act of disturbing the wires while installing/removing the starter might have caused it to come into contact with the body and caused a short unrelated to the starter itself.

I wonder if the starter would run backwards on a bench test if it was wired wrong internally, causing an immediate short to ground in the car.

PHOTO'S !!!!!!!!! I read two or three posts asking you for photos so we/ they can help. Post some photo's.

I will post pics this weekend.

I'm thinking in the same direction as Mr Project ... To be continued!