Precarious ground / starter relay

[sam z]

Ok, it's never simple or straightforward.

By-passed the relay, car fired. Easy fix. New relay from the far east and
start it, right? Of course not.

Same crap, it will start by passing the relay, but not without. Ran some tests
on relay spade terminals. When regular ground (the spade on the right, facing
the firewall) was hooked up, nothing. We ran our own ground from battery to that
terminal and the car fired. So...must be a crap ground wire or connection somewhere.

So, please read this part:

We put a new ground on from the spade terminal on the relay to the negative post. Car fires
no issue. This isn't obviously OEM, but it works, good nonetheless. Can this be
left as is -OR- Should I take the time to find the problem with the OEM ground
and rewire it? Thanks in advance.

 

[Big John]

OK... The terminal you speak of... Is that the one for the neutral switch? That could be the switch or bad ground to the engine/trans.

If your car is a 4 speed, I believe that terminal is grounded to the case. In that case, the ground from the firewall isn't good. The usual cause is dirt or more likely, paint.

 

[sam z]

John, first thing is thanks for responding. Now:

Yes, it's to the neutral safety (auto). When we tested it (at the spade terminal) we had voltage, but it was REAL low. When we
re-grounded it elsewhere, the car fired no problem, indicating that is was a poor ground for some reason.

Incidentally, I just got off the phone with the guy that helped trouble shoot it. He went home and researched it
and made me aware where the original ground runs to (safety switch).

Ended it this way: Leave it wired as is to get back and forth to show for this coming saturday. Then, completely replace
that ground wire properly in a week or so from N.S. switch up to the relay.

Any issues with this approach? My assistant says we should be ok.

 

[sam z]

Oh yeah...I've had hit and miss back up lights for a while too.

 

[Big John]

Oh yeah...I've had hit and miss back up lights for a while too.

Ah Ha!!

The neutral switch and the back up light switch is one in the same!

So... there is a "harness" with three wires ending in a plug in terminal at the switch. Either the switch is bad or (more likely) the plug is bad... OR just loose, dirty or unplugged!

Take the plug off, spray it and the switch with some contact cleaner. Plug it back on and see what happens.

 

[4spd69RR]

Is the ground wire original? If so it is a copper wire and has corrosion throughout the cable, replace it.

 

[A31PKG]

When running the ground terminal straight to battery ground - and the engine fires - you are by-passing the neutral safety switch circuit. This means that either A): the harness or connector is bad, or B): the switch is bad. As Big mentioned check this harness, the female connector terminals at the end of it, and the switch. If you can work a pair of needle nose pliers into the rubber switch molding, give the female terminals a little squeeze so they bite the male switch terminals better.

 

[sam z]

Ok guys - got it on all. The wire and the switch will be replaced. Can't hurt seeing that they are
both 43 years old.

 

[mac]

if the weather holds out, get that car ready for the show saturday.

 

[sam z]

Was on it ALLLLL day today believe me Mac.