Is the starter relay the problem?

[rickseeman]

When you turn the key the oil light dims but the starter doesn't engage. You can jump it across the relay and it starts fine. Is that normally the starter relay? I guess the neutral safety switch would be another suspect? 1969 Road Runner, auto trans. Thanks

 

[dadsbee]

Pull the yellow wire off the firewall relay. Jump the BAT terminal to the spade you just took the wire off. If it cranks it's not the relay, if it doesn't that is your issue.

 

[rickseeman]

Thank you, I will give that a try.

 

[59pwrwgn]

Relay needs a good ground also.

 

[pnora]

Relay needs a good ground also.

That style relay does not need to be grounded in the automatic transmission application. Manual transmission yes.

 

[Unkle Krusty]

I have been working on the almost same problem. Thought is was the relay. Made decent grounds first. Removed the red wyre. Problem was volts dropping when key turned to crank.
It is the key switch on mine. New switch three years ago.
Have a push button starter button. Checked it, and it cranks okay. Will connect it tomorrow and check volts again while cranking.

 

[OneWheelPeel]

I’ve had the same problem, but it’s not consistent. I temporarily added a push button which always works that jumps the terminals on the relay, because I’m paranoid it will stall at the worst time and the key won’t work.

 

[451Mopar]

Make sure your in park or neutral with brake on when testing just in could the neutral safety switch is doing its job and the shifter is mis-adjusted.
I'd disconnect the neutral safety wire (I think it is brown with the "L" shaped plastic connector at the lower right of the relay for an automatic trans car), and use a jumper wire to connect that relay terminal to ground. Remove the yellow crank wire from the ignition key and use a jumper wire to connect it to the battery power (stud on the relay) and the engine should crank if the relay is good. If no crank the relay is likely bad, try jumping battery stud power to the relay output (I think Purple wire that has the screwed down connector) going to the starter solenoid. That should crank the engine according to previous testing and verify that it is the relay that is bad.
I just replaced that relay on the '69 Coronet 500 early this year because mine was bad too.

Might want to check the bulkhead connectors too. I disconnected mine and found a bunch of corrosion. Also cracked the wiper connector to the bulkhead.

 

[Cranky]

That style relay does not need to be grounded in the automatic transmission application. Manual transmission yes.

Used to ground the relay on my automatic cars....scared the snot out of a neighbor one day by getting in and matting the loud pedal. My exhaust wasn't real loud but loud enough plus the squalling tires didn't help matters much. From nearly a dead silence to a good roar with just the turn of the key. He let me know about it when I got home later.

 

[rickseeman]

I was looking at that bulkhead connector (and the others) and wanted to pull them apart and put them back together. There has to be corrosion after 55 years. We're going to fiddle with it this afternoon and try to find the problem.

 

[Cranky]

I’ve had the same problem, but it’s not consistent. I temporarily added a push button which always works that jumps the terminals on the relay, because I’m paranoid it will stall at the worst time and the key won’t work.

Had two different cars that did that.....kinda odd that both of them were 66 Belvederes. My first car would do it every few months. Get out and get under the hood and cross the relay and fired up and would be fine for several months or longer. My second 66 did it one day at work just as it started pouring rain. Crap....didn't feel like getting soaked. The car didn't have carpet but came with rubber floor mats and thought about slamming my work boot to the floor with the key in the start position. It worked! Got to thinking how weird that was with 2 different cars and 20 years apart.

 

[Fran Blacker]

The tab on relay that has the wire to NSS needs to be grounded. Be careful car isn't in gear!! when you hit the key.

 

[Unkle Krusty]

Top left on my relay goes to ground. Top right is the power, or hot wyre when the key is turned. Middle left is solenoid, a thicker wyre, but not heavy. Bottom is the battery red on the stud, along with the heavy wyre to the starter. Mine is an auto.

The connections thru the bulkhead can get fuzzy, and the original fuses too. Nothing in my original dash works, so I am replacing all. Next winter I will likely replace all the wyring.
Already use a boat style fuse panel.
Just made a list of everything that should work. Note above reminded me of the neutral safety switch.

I have the original battery cables, and they are not very heavy. Mine is a B200 van. Not too concerned about original with respect with wyring. More concerned with the Tukvan running reliably. But we are original outside with the ugly “ Harley “ stripes.

 

[pnora]

Top left on my relay goes to ground. Top right is the power, or hot wyre when the key is turned. Middle left is solenoid, a thicker wyre, but not heavy. Bottom is the battery red on the stud, along with the heavy wyre to the starter. Mine is an auto.

The connections thru the bulkhead can get fuzzy, and the original fuses too. Nothing in my original dash works, so I am replacing all. Next winter I will likely replace all the wyring.
Already use a boat style fuse panel.
Just made a list of everything that should work. Note above reminded me of the neutral safety switch.

I have the original battery cables, and they are not very heavy. Mine is a B200 van. Not too concerned about original with respect with wyring. More concerned with the Tukvan running reliably. But we are original outside with the ugly “ Harley “ stripes.

You should start your own post with your problem and questions.

 

[70bigblockdodge]

Had a less than a year old starter relay go bad on power tour last year. Apparently not made like they were.

 

[GTXDAN]

Had the same issue with my 70 GTX. Would crank with the relay when jumped but not with the key. Pulled the bulkhead connector apart and cleaned all the terminals. No visible corrosion or hot terminals and nothing melted. Sprayed them down with terminal cleaner and acid brush and brass brush. Applied some dielectric compound, reinstalled and worked great after that.

 

[Unkle Krusty]

You should start your own post with your problem and questions.

Fixed my problem with a starter button.
But the OP might have similar problems as I have alluded to. Some of the replacement parts are likely made in China, and subject to fail far too soon.

 

[rickseeman]

Pull the yellow wire off the firewall relay. Jump the BAT terminal to the spade you just took the wire off. If it cranks it's not the relay, if it doesn't that is your issue.

OK, I tried that, and it didn't crank, so we're going to get a new one in the morning. I'll report back.

 

[pnora]

OK, I tried that, and it didn't crank, so we're going to get a new one in the morning. I'll

You have to verify the other small terminal is grounded. If its not grounded jumping it will not prove anything. That other terminal is what your NSS is grounding.

 

[Black_Sheep]

That style relay does not need to be grounded in the automatic transmission application. Manual transmission yes.

The relay for an auto transmission grounds through the center pin of the neutral safety switch. I was having intermittent issues with the GTX that continued after replacing both the relay and NSS, it turned out to be an internal break in the harness near the NSS plug.