Ok this is going to be kinda long winded. If you wanna read the short version, scroll to the bottom.

I have a 92 SC400 for my daily driver, just small stuff done to her, cone filter (too lazy to do bfi), coilovers, wheels, and HIDS, so nothing major.

When I first got the car, I did the timing belt, water pump, and all that jazz, then my alternator went, so I just replaced that.

Now i'm having a starter issue, I've read about how to replace, and check the contacts and whatnot on the starter, but my issue is different.

I'm getting starter run on, at first it was random, I would drive and then it would do it, the car wouldn't run, everything would shut off. I went to inspect everything, and my negative battery cable was loose, I went ahead and tightened it and it went away for a few days.

As of today, I started driving her, and then bam starter run on. Shut the car off for a bit and it went away, drove it back to my shop, and it happened again.

So i'm trying to figure out what is going on. I turn the car back on, and it runs smooth as silk, turned the heater on, and BAM starter run on. I shut the car off and on, and switch the heater on and off, and everytime the heater was on, it would have starter run on.

After a few more tries, it went away, even turning the heater on and off, it would NOT have starter run on, I go gun it down the street, I turn around, and as i'm about to gun it again, I get starter run on, but for ONLY a quick SECOND, and it goes away.

I let the car sit all day (after going to austin for my niece's b-day), and I come to pick her up, and now every time I turn on the key, the starter automatically starts going, and it doesn't stop.

Here's the short version

Starter run on, goes away, comes back a few days later, sits for the entire day, try again and now the starter starts going with just the key in the 2nd position (after the ACC).

I'm wondering if anyone else has had this problem, I'm sure everyone is aware that the starter is ONE hell of a job. I'm also wondering if someone has the starter wiring diagram.

Thanks

 

If I'm understanding you correctly your starter randomly/ sometimes continuously starts engaging. The problem (if decently nominal) is going to be either the ignition switch going bad or the starter relay dying out on you. I would've offered a hand seeing as you sound fairly close to Houston but then I read you had the SC400 sooo.... its ALL you because that IS the dumbest location for a starter that I've seen. Start from there... even if someone posts the diagram you're still going to have to go through what I just mentioned. Start from the relay side as its easier.

Above was if it was nominal, it could of course be something more involved like fubered up ghetto wiring job previously performed or some form of heat damage (melted wires).

Kruso

 

Lol tell me about it...I'm dreading this too...Guess I'll be driving my s13 again with my beat up top...

You are correct, my starter engages on it's own, at first randomly, but now constantly.

I'm starting to think it's wires, considering it's a 92, and the woman that owned the SC4 prior, didn't take very good care of it.

The reason why it lead me to believe that it is the wires, is because that turning the heater applies some sort of load, and my motor mounts are going bad, caused it to shake enough to have the starter wire ground out.

Another thing is the fact that the last time I did drive her, she started the starter run on THEN stopped. She did not do that prior. It was either starter run on, or not at all.

 

Fixed it, after I talked to my old man about what was happening, he told me to go out to the car, and lift up on the key itself, and then crank it. I kinda shrugged him off, but then I tried it anyway. And guess what? It worked. I called him back and he gave me his "I told you so f--ker" voice, and he began to explain what had happened. Over time the actual ignition tends to sag, and if it does, then the car will do that.

Saved me a lot of time so I didn't have to replace the starter, if I did that, and still had the same problem, I'd be soo pissed. So now my lexus has some ghetto rig in it.

Got my starter on a switch

 

Called it

 

yeah yeah, but you didn't tell me to lift the key

 

Well I'm getting the problem again, but it's doing the original starter run on, while the heater is on....but the key on it's not doing it anymore...

DId some testing, and it seems like the heater control is the problem..

Does anyone know if they are different?