Starter relay clutch ground

[ek3]

No start unless I jump a ground wire to battery from clutch green wire.i assume the relay needs a ground to the body. I changed the brand new relay with one from Mancini and same issue. I have thoroughly cleaned the panel to bare metal behind the relay and I am satisfied its not the issue. Trying to keep it in original looking fashion however, I think I can just run a small ground wire behind the relay and tie it to something that is a good ground. Anyone else do this neatly? Any problem with just grounding the green wire and bypassing the relay?

[dodj]

The relay needs ground. If Automatic it is supplied by the NSS. If manual it is supplied by the clutch switch on the pedal. That clutch switch is pricey if you don't have one. On my car the relay ground terminal is grounded within the dash wiring because I'm too cheap to buy the switch.

[Katfish]

No problem just grounding it.
But you need to be careful.
I could never get my auto NSS to work, so it's grounded.
But I have scared the sh*t out of myself when car moved forward after starting it in gear.
It doesn't just lurch forward, car actually started and ran.

[moonshine_mike]

Just checked. Encountered sticker shock when finding out how pricey these have become. Thankfully I have all I need but if I had to do another 4 speed I would likely go straight ground as well.

[1970Cuda]

Definitely the clutch switch is pricey (around $500) and really hard to find. I cannot believe no one has reproduced these yet. And the 1970 is (of course) different from the '71 -'74s. Does anyone know of a source? Fortunately, the '70 can be rebuilt if a person can find one.

[pschlosser]

Definitely the clutch switch is pricey (around $500) and really hard to find.

If you must have an OEM one, they are indeed pricey. 

But the reproduction ones sell for less.  I've seen kits sold at swap meet for about $200.

[ek3]

The relay needs ground. If Automatic it is supplied by the NSS. If manual it is supplied by the clutch switch on the pedal. That clutch switch is pricey if you don't have one. On my car the relay ground terminal is grounded within the dash wiring because I'm too cheap to buy the switch.

so the relay is not the issue. It is the actual sending unit at the clutch pedal that is not grounding correct? If I ground the green wire to the battery, the clutch switch functions as it should. I'm having trouble understanding why when I connect the ground wire to the relay it will not work. I am certain that the relay is metal to metal and it's is bolted securely and tightly. It seems somehow internally the relay is not providing the ground. I was wondering if I could just go under the dash and add or splice in a ground wire from the Green we're going to the switch and just provide it with a ground. The switch would still operate as it should.

[1970Cuda]

Now that is good to know that someone does reproduce those switches! And $200 is around the price to have one's own original rebuilt. I do prefer the original parts, but unless someone is doing a points car, for me, the repop that works well is good enough.

[moonshine_mike]

Its the relay terminal (green wire from clutch pedal switch) that needs the ground during the start function. The relay assembly case is not connected internally to the terminal that the clutch pedal switch wires to. The clutch pedal switch under dash connects its mounting ground to the green wire when the pedal is depressed. Then the terminal gets the ground allowing the relay function to work leading to engine start. If somewhere in this path the ground does not get to the terminal of the relay, engine start is prevented from happening. Permanently grounding the terminal to any chassis point or battery negative should do the trick. This does not bypass the relay. It simply bypasses the clutch switch under dash.

[1970 cuda Joe]

My 70 'cuda had the 71-74 version & it had a small, sweet spot when you wanted to start it. I ended up just grounding a wire from the terminal to one of the screws on the starter. Since I'm in my late 60s my father & the driver trainer instructor always said, "Make sure a car is in neutral before you start it". Good words......Joe

[Chryco Psycho]

O n a couple of builds I just used a brake switch , it won't start unless the pedal is depressed but it will start with the pedal only down an couple of inches

[dodj]

I am certain that the relay is metal to metal and it's is bolted securely and tightly.

It's not like the VR where the case is the ground path. The starter relay case is isolated from the inner workings. So the wire attached to the G terminal is where it gets it's ground.

[dodj]

O n a couple of builds I just used a brake switch , it won't start unless the pedal is depressed but it will start with the pedal only down an couple of inches

I may do something like this over the winter.
How many years of no winters have you had now Neil?

[ek3]

Its the relay terminal (green wire from clutch pedal switch) that needs the ground during the start function. The relay assembly case is not connected internally to the terminal that the clutch pedal switch wires to. The clutch pedal switch under dash connects its mounting ground to the green wire when the pedal is depressed. Then the terminal gets the ground allowing the relay function to work leading to engine start. If somewhere in this path the ground does not get to the terminal of the relay, engine start is prevented from happening. Permanently grounding the terminal to any chassis point or battery negative should do the trick. This does not bypass the relay. It simply bypasses the clutch switch under dash.

got it. I was thinking the relay was the grounding point, but that terminal on the relay requires the ground. I understand completely. Now I wonder if anyone has a photograph of the internals of one of these switches taken apart I would be curious to know if it could be modified internally with a more simpler design. I'm sure getting one apart could be a challenge just as much as reassembly would, but on occasion I have good luck with doing these things.

[dodj]

Selectively providing the ground is what makes the starter not engage when the clutch pedal is not depressed or the auto trans not in neutral. Making it 'simpler' by internally grounding the 'G' terminal would defeat the relays safety purpose. If you want to do that in an unnoticeable way, just ground it away from the relay.