[FJ70 3F] How do I install a relay for the starter? (1 Viewer)

[MalcolmY]

Hello

I really need to install a relay between the starter and the ignition switch. The circuit goes through the ignition switch itself, the OEM switch wires melted from the heat, the new aftermarket one got really hot today.

I would really like to bypass the switch itself, I know it can be done and I know others have done it I just don't know to do it. I'm mechanically inclined and can follow instructions. I would appreciate any help.



(original problem explained below for the curious)

So the original issue is intermittent, the starter doesn't turn for a while. I have to hold the key for a number of seconds (after a few tries) until it it sucks insane current that satisfies it.

I took the starter off and bench tested it. The motor itself spins each time no problem. But the solenoid doesn't, it works intermittently. I took apart the solenoid and didn't see any obvious issues.

Continuity test shows continuity between the terminals and the body, which I found weird. But I confirmed it with a known good solenoid, same thing.

I cleaned what I could, it worked for two weeks without any issues the few times I started the truck. But today it wasn't working. I tried banging on the started (both sides of motor and solenoid), didn't seem to help. It only started when I held the key on for a few seconds risking melting the ignition switch and it's wires.

Thank you all.

 

[roscoFJ73]

I would fix the problems and I would start by measuring the voltage at the starter when its cranking. Bypassing things is not really a good way to solve a problem.

 

[MalcolmY]

I would fix the problems and I would start by measuring the voltage at the starter when its cranking. Bypassing things is not really a good way to solve a problem.

Well the problem is sneaky* and difficult to diagnose for sure. I have narrowed it down to the the starter solenoid. I bought a used solenoid from another Toyota car that fits my starter but didn't install it yer because the problem suddenly went away! Whether this fixes my problem, or whether I need to buy a new starter, in all cases I will install a relay. I don't like having all that current going through the ignition switch.

I just need help with installing it.

* Example:
I was bench testing the starter, the motor works by itself every single time. The solenoid wouldn't. I gave up and took it to car electrician looking for a used solenoid, he did his bench test the same EXACT way I did, the F#%er worked immediately. He said: this starter is okay. Well, just an hour ago it wasn't.

 

[jblueridge]

You should read up on 4 pin relays. You will need to mount it in an accessible spot so you can replace it if necessary. You can get a relay with a 4 pin socket and bracket so it will be easy to service.

 

[roscoFJ73]

I was bench testing the starter, the motor works by itself every single time

Is i getting a better source of power when its bench tested? Try a jumper lead connected to the starter.

 

[jblueridge]

Much more difficult I am sure, but if you could get the whole vehicle to the electrical shop maybe they'd experience the same as you.