crossed +/- starter wires, oh S#!% now I did it...

[Rufusbird]

I need some help... does anyone know of a similar "issue" ?

I screwed up trying to replace the starter. Managed to switched the starter +/- wires. (yeah, that was brilliant) Big sparks when I tried to reattach the neg. terminal to the battery also the starter started whirring (backwards I assume.)

So I switched the starter terminal wires around (and prayed) it started! cool, I'm thinking, it starts and runs. BUT lots of lights on... - SRS, alternator light dim, brake lining, check oil, etc.

Bentley manual states: "...a high, soft whistling sound may be produced by an alternator that is overcharging because of a faulty regulator diode." Yup that's me too.

(So a new alt. w/ regulator right? or ? < really hoping I don't have to $)

I turn off the engine and start it again, starts up and most lights go out. Thinking the computer needed to reset I drive off for a test. No power brakes; SRS light still on and alternator light very dim, idle was slowly moving between 500-900.

Stopped the car and tried to restart- nothing , car wound'nt take a jump either. I'm thinking at this point;
A) alternator and/or voltage regulator fried also?
B) starter solenoid is def dead now?
C) a relay shot?
D) ECU smoked
E) all of the above?
(NO fuse to the starter it's wired direct... nIce.)

can anyone help out? thanks,
Tim

[jlevie]

The brakes don't depend on the electrical system, so that's a different problem. I'd start checking fuses and have the battery tested. And you may have fried the alternator. The warning lights could be from low system voltage, which would be plausable if the batter and/or alternator are dead.

[Rufusbird]

jlevie,

I'm in agreement with the alternator being probably fried. also the battery may be weak and that's adding to this problem? I'll check the voltage. I'm just hoping the voltage regulator could be it, as it is much cheaper than an alternator.

good point, the brake is something else, I did remove a brake hose trying to get at the starter must have not hooked it up well.

this happened last night so my buddy is giving me a lift to check out the car in the day light. Maybe something is obviously fried upon inspection.

thanks for the response and input.
Tim

[jlevie]

If the vacuum line to booster isn't connected you'd have a sizable intake leak, which would explain the low idle as well as the loss of brake boost.

[Rufusbird]

FU starters on e30's ! Christ... and don't do it by yourself like I did

the old starter was dying, I was replacing it anyway, but I killed it completely by reattaching the wires wrong .

the alternator appears OK after a long test drive.

lack of brake boost was a poorly reattached hose and clamp. seems obvious now that you mentioned it. i was only thinking $ not logically

thanks for the input
peace

[ptownTSI]

wear a long sleeve shirt when you change the starter otherwise you get your arms scratched to hell trying to get wrenches in there. I did a complete tranny R&R on my back in the rain with jackstands once...

[Rocla]

Now I'not following you... what wires did you cross exactly? since starter hasn't separate ground cable or terminal.

Do you mean battery cables?

It sure sounds like burnt diode on alternator, even a heavy short wont usually harm alternator, but putting the battery wrong way around most certainly does.

[Wiglaf]

here's my theory:
that starter motor has a clamp diode to prevent a huge voltage spike when it turns off. if you hook the thing up backwards, you fry that diode. it was probably shorted out. when you put the wires back the right way, it remained as a huge load on the electrical system, probably draining the battery out and the alternator couldn't keep the voltage up to where it should be. but it tried, and bucked all that extra power to the engine which is why it idled slowly.
what i don't get is why it didn't just trip a breaker of fuse or something, that's the sort of stuff that starts fires.

[jajou318]

Shouldn't you have disconnected the battery first?

[Rufusbird]

Now I'not following you... what wires did you cross exactly? since starter hasn't separate ground cable or terminal.

Do you mean battery cables?

It sure sounds like burnt diode on alternator, even a heavy short wont usually harm alternator, but putting the battery wrong way around most certainly does.

the theory that I fried the starter diode and the alternator put out straight to the engine sounds right (I don't claim to be a pro at all here) as I did drive the car afterwards and did make it far enough (xmas lights on the dash etc.) to stop, return and nothing, not even a jump would help, hitting the solenoid, some faint clicking and whirring noises, not moving

So far the alternator appears well, no burnt diode as I can tell, but I haven't done any elec. checks- I'd have to read up on how. Made it to work and back no problems so far.

The starter is wired direct to the battery, NO fuse! to answer another ques.

The battery WAS disconnected, it was when I tried to reconnect it that I got the huge spark because the starter was wired wrong. The black and red starter wires were on seperate terminals (4 terminal type- red close to the engine, black the farther on) according to the electrical diagram in my now returned Bentley manual they go on the same post (I never would have guessed that) Plus I didn't remember which was which so my fault for not paying attention to wire placement or verifying before connecting.

(shorting caused slight melting of battery posts where contact occurred- off the subject but apparently you can emergency weld with 2 batteries hooked up and the right rod - never tried it but read it in a four wheeler mag. once and I believe it.)

what can I say? I don't claim to be a pro ha, ha, ha

thanks for the discussion

T