Transmission wiring

[paul mora]

I need help I am wiring the tranny and I was told i need to install a relay downstream of the neutral safety switch on the tranny. The photo shows the pins and where the wires connect to based on a,b,c,...... first question is do I need the relay and if anyone could simplify
A not used
B
C. Fused hot wire on or off when cranking
D. Ground
E to relay this trips relay
F back up or reverse light
G

If anyone can answer my relay question and fill in the blanks and tell me how to wire this I might get it running.

[prodjay10]

Why do you need a relay? Is it for tcc lockup?

[prodjay10]

Why do you need a relay? Is it for tcc lockup?

[ls1nova71]

You only need the relay if you are going to use the neutral safety switch on the side of the transmission for an actual neutral safety switch. Most people will just use the existing NSS on their column and not the trans one.

But if you want to use it, it is wired like this-

The wire from the ignition switch, the one that is hot when you turn the key to "crank", usually purple on older GM vehicles, will go to pin E, the pink wire. Then pin G the yellow wire will go to terminal 85 on the relay. Terminal 86 will be grounded. Terminal 30 will be a constant power, with about a 40A fuse and then terminal, 87 will go to the starter solenoid.

[paul mora]

Ls1nova71 Just curious what is B used for

[ls1nova71]

Pin B is for the shift interlock, its what makes you have to apply the brake to shift out of park. If you use that for a neutral safety switch, it will only start in park and not neutral.

[paul mora]

Thanks everyone for the help I talked with a Bill over at B&P and he said they no longer leave a wire in the harness for the trans nss. I dropped the relay and use the nss on the steering column cranks just fine