Fried_Rice

I've hooked my starter switch to my switch panel in my race-car which gives a 12v signal to the starter to crank. The wire worked for a while, but I realized it was grounding out last race and the car would not start.

Is the switched terminal for the starter ground instead of 12v? I've tested the starter 5/16" small prong and it's grounded.

Red text is how it was previously hooked up.

Thanks for your help in advance!

garys 68

iTrader: (1)

How exactly are you measuring "grounded out"?
Btw, +12V applied to the small post on the solenoid will engage it and the starter motor.

Fried_Rice

That's what I believed and it does start the starter when 12v is applied.

The weird thing is when I touch my volt meter from the small post/larger post going to the starter. It reads continuity, very low 1.5 ohms, to the engine ground/chassis ground. Volt meter has the audible beep function when I touch from the small post to any ground. Power wire from battery is not grounded out and shows no continuity to ground.

Also when I touch the starter button, the 12v switch wire immediately heats up and my battery loses voltages to 6-7 volts(grounding out). It melted the wire and my battery ground off the battery. I can hear arcing out as well. This is the second starter, my other one got completely fried.

I'm not comprehending how the two post that are supposed to engage the starter are grounded on both starters. I've ran no grounds to the starter.

This is a picture of the melted wire. That's melted wire loom.

garys 68

iTrader: (1)

What gauge wire was the melted one and what was it connected to?

Fried_Rice

12 gauge connected to my push button start. The panel came with that thickness. I can replace it with 8 gauge. My other engines never had a problem with the 12 gauge.

fastassls1maro

iTrader: (22)

a 10 or 12 gauge wire should be more then enough to power the solenoid on the starter. The reason you are getting a reading (1.5ohms) when checking the small post to ground or the larger post to ground is because you are essentially reading the resistance through the solenoid(small post) or the starter motor(large post). I would suspect the the power wire from your switch may have rubbed through somewhere and its grounding out. The solenoid on a starter requires only 20-30 amps and should not melt a good 10-12 gauge wire.
Hope this helps

Paul Bell

iTrader: (9)

Fried_Rice, the original way you had it wired was correct.

As it worked and then stopped working, the wiring was correct but something else went wrong.

The factory uses like a 16 gauge wire for this, I'm certain the amperage draw of the solenoid is pretty low-like 2~4 amps.

Fried_Rice

Thanks to everyone for posting. I replaced the wiring and it's not grounding out, nor was the previous wiring. The previous starter could have been bad, I will try again today. I didn't want to fry a brand new starter if the wiring was incorrect.

garys 68

iTrader: (1)

Well as others have pointed out, there should only be a few ohms resistance at the solenoid, that's normal.
Was the fried wire at the push button end or solenoid. A 12g. wire should be more than adequate for the solenoid connection. If it melted at the connector end I'm guessing it was a poor connection, crimp, broken wires.
Also be sure the solenoid extends and starter spins. Locked up will heat up fast.

Fried_Rice

Thanks everyone for posting. And here is an update and solution to my problem. The melted wire was at the starter end, and now that I think about it, could have even been caused by the heat from the header. But I doubt it.

Firstly I re-did the ground cable to the battery. Secondly I added another 4 gauge ground from the engine to the chassis. Car runs better than ever and starts up immediately without dropping voltage.