Starter Relay Wiring

[716PKRT]

Ok, I'm hoping someone on this forum can help me. I bought a 1972 Satellite Sebring to drive and "play" with. 318, console auto. This car looks nice (20 footer) and runs well, but has had a lot of "shadetree" work done, probably by some Chevy hack or someone who just fixed and flipped the car at some point. Anyway, I want to replace the starter relay, which appears to be from a 1991 Ford Pickup, with an original style Mopar one. Looks like all the correct wires are there and going to the correct places, at least to the correct firewall pin locations according to the factory wiring diagrams. But every time I hook up the Mopar relay correctly, it won't even turn over, so it's not getting a signal to the ignition terminal on the relay to spin the starter. Could the ignition switch in the column be bad? Before I pull the column and tear into it, I'd like to try everything else. Any suggestions would be appreciated. Thanks. Dan

 

[Crackedback]

test light?

check the signal wire, yellow iirc, when you turn key to start.

did it start with the ford relay before changing it?

 

[Don Frelier]

Try grounding the terminal to the neutral safety switch. It may have been the original problem.

 

[716PKRT]

test light?

check the signal wire, yellow iirc, when you turn key to start.

did it start with the ford relay before changing it?

Yes, it starts with the Ford one. I'll try putting a light on it. Somehow, it must get signal to the Ford relay so it makes me think the internals are different.

 

[716PKRT]

Try grounding the terminal to the neutral safety switch. It may have been the original problem.

It starts with the Ford relay. I grounded it before and it didn't make a difference. Thanks.

 

[Don Frelier]

Sure seems as though the relay is no good.

 

[1 Wild R/T]

Ford relay grounds through the mounting bracket... It has to be getting 12v from the ignition sw since the Ford relay works...

 

[716PKRT]

Ford relay grounds through the mounting bracket... It has to be getting 12v from the ignition sw since the Ford relay works...


View attachment 1338433

 

[716PKRT]

Yeah I figured since the paint was ground off where the relay is mounted.

 

[716PKRT]

Sure seems as though the relay is no good.

I tried two different ones and also the one from my Challenger that I know works and none of them will crank. It's frustrating because I think there must be something that has been changed in the wiring. I wanted to avoid time spent under the dash to trace wires since the ones in the engine compartment are right. At 64, contorting under a dash is not pleasant!

 

[1 Wild R/T]

If you apply 12v to the diagonal blade style terminal & ground the vertical blade style terminal the relay should click indicating the contacts have closed joining the battery stud to the start connection.... If there's no click the relay is defective... Which wouldn't surprise me since I've seen to many defective electrical components out of China lately...

 

[1 Wild R/T]

Yep, I get your under dash comment & total understand... And like you say, you should have what you need under the hood...

 

[Shorthorse]

Does the Mopar relay click when the key is in the start position but the starter does not turn over or is there absolutely nothing?
There's a big difference between the two starter relays.
Ford starter relays are designed to deliver high current to the starter motor and the solenoid at the same time. There is no constant power down at the main starter post.
Mopar starter relays are designed to deliver power to the solenoid only. The main starter post has constant power at all times.

 

[steve340]

Mopar relays have to be earthed through the clutch safety switch or park/neutral switch to operate.
If you have one spare terminal on the Mopar relay this may be what is missing.

 

[1 Wild R/T]

Does the Mopar relay click when the key is in the start position but the starter does not turn over or is there absolutely nothing?
There's a big difference between the two starter relays.
Ford starter relays are designed to deliver high current to the starter motor and the solenoid at the same time. There is no constant power down at the main starter post.
Mopar starter relays are designed to deliver power to the solenoid only. The main starter post has constant power at all times.

Good point... I/we made a mistake & assumed the battery cable was routed down to the starter...

The battery cable feeds power to the big post on the starter relay but it also feed the major current load directly to the big post of the starter...

The small screw connector on the starter relay should connect to the small solenoid connector on the starter...

 

[716PKRT]

I'll have to check tomorrow. I can't hear the relay click when I'm in the car trying the key. Will have to get someone to turn the key while I'm at the fender listening. I might just try it on the bench to see if it clicks, but it also didn't work with the relay from my Challenger that works fine on that. I get the comment about junk China parts. I have dealt with too many non-functional parts right out of the box to know you can't assume a new part actually works. I appreciate all the help. I'll post tomorrow when I try a few of these suggestions.

 

[716PKRT]

I think it's the neutral safety switch, even though I grounded the relay terminal before and it didn't make a difference. I tested for continuity at the switch and there was none. I also did what I never tried before, which is to start the car in gear, which it did. It's either the switch or the operating cam inside the transmission that is not making contact. Since I haven't owned this car that long and much previous work is "sketchy", I don't want to assume anything is right. The switch is hard to get to and I won't be able to see the cam position laying on the floor. I'll have to get it up on a lift somehow.

Thanks to everyone who replied on this. It really helped me narrow the problem down. I hope replacing the switch will straighten out the wiring issues.

 

[steve340]

The switch is probably OK.
Try a switch adjustment procedure.

 

[716PKRT]

The switch is probably OK.
Try a switch adjustment procedure.

Switch adjustment procedure? Do you mean the console shift linkage adjustment procedure? I have to factory manual and it doesn't mention a switch adjustment procedure for this.

 

[steve340]

It is in the transmission section page 21-48 of my 1968 FSM

Your switch is working because it can enable/disable the starter.
It is just doing it in the wrong place.