Starter relay wiring diagnostics

[TTait]

Now that I've specifically named the issue In the thread title , something is bound to happen and my actual problem will be something else, let's hope I've diagnosed this right.

First, my starter was fine, but we think that in a 1 in 100 shot a dropped exhaust manifold washer found its way between the teeth, and jammed it. The solenoid would pull and the motor would draw current but not turn.

We pulled the oem starter loose, tapped a bit, reinstalled it, and it worked.

Then an intermittent issue came up where occasionally it seemed the relay would click, but no cranking. A day later it might work again.

Then a day turned into a week the next time it failed, and I assumed I'd burned up a brush on the starter, so I installed a Mitsubishi style unit.

I tested the Mitsubishi after installation by jumping power to the solenoid, and it works fine. When I turn the key, I thought I heard the relay click, but I was mistaken. I think what I'm hearing is the master relay. Not sure where it is, but it's odd to me that it's clicking when I turn the key to start, not accessory.

Turns out my starter relay is not pulling.

The relay is fine. I have 12 Volts coming in presumably from the brown wires and circuit breaker, a good ground from the transmission switch, continuity from the output pole to the starter, and when I apply 12 Volts to the output socket, the starter turns.

I do not however have the 12 Volts feeding from the ignition switch to the relay socket when I turn the key. I believe that if I did, the relay would close and the starter would work.

Additional Info:

I think the starter recall was performed, as I have 12 Volts at one pin in the relay socket, but not both.

My cabin fan works on speeds 1, 2, and 4, not 3. I presume the resistor needs to be checked, but the circuit breaker is fine. Further, I believe my issue is that the relay is not closing, not that the load current is not present.

I don't hear anything from the key chime, but I'm not sure when I should?

I do hear a clicking from the relay compartment when I turn the key to start/crank, but I don't think I should. This happens even when the starter relay is removed.

Because I do hear said clicking I presume the ignition switch is working properly. Maybe not though. You tell me.

I have Toby's alarm/ door poppers, fanzilla, lockzilla (Iirc) installed, so there is a lot going on in the wiring bay.

My question is next steps. Should I try to access the back side of the relay socket, and if so how? Next steps in troubleshooting? Warnings, anecdotes, or advice appreciated.

Tom

[DMC5180]

Hi Tom,

Regarding he intermittent starting, check the start inhibit relay socket too see if all terminals are present in the socket. Meaning one of them isn’t pushed out the bottom. 30,85,86 and 87 should be visible near the top of the slots. I believe 87a (N/C) is empty.

I have a buddy that had an intermittent starter issue. It turned the white/red wire terminal in the 87 slot had pushed back out of the housing and was just touching the relay spade terminal.

Regarding the 3rd speed fan, your blower resistor is good if you have 1-2 and 4. However, it is possible you could have a bad contact on the yellow/white wire terminal. Verify you have 12v too the 3rd speed relay with the fan switch in position 3. Also verify the ground side of the relay socket to ground.


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[TTait]

And now... It's working again.

I do not count this as a victory...

I suspect you are right, as the only thing that changed was plugging and unplugging the relay with and without extension jumpers.

[Bitsyncmaster]

Don't forget a relay needs a ground for the coil voltage to operate it. I've not seen a back side relay bank ground failure yet but have seen a few on the front bank. It something that looks like a good crimp but the double wire crimps seem to fail with age sometimes.

To pull up a relay bank, you need to remove two screws (one in two of the relay sockets).

[David T]

Because you have an automatic the start inhibit relay can prevent the starter from operating. That start relay is controlled by the shift computer and the neutral safety switch. You can have a bad connection, a mis-adjusted gearshift, a burned cable to the shift computer, a lot can go wrong. First step would be to bypass the inhibit relay and see if the problem goes away. Just be extra careful to ONLY start the motor in Park or Neutral. If the problem goes away you then must go through the circuit that controls the inhibit relay wire by wire, connection by connection. A good place to start is the relay itself to make sure none of the connectors "backed out" of the fuse block and is only touching, not gripping, the terminals of the relay. Next I would carefully inspect every inch of the wiring harness to the shift computer. If not secured away from the hot exhaust pipes they can get burned.