[VetteVet]

Originally Posted by hdff

vettevet my nss is not hooked up either so i assume my purple wire off the ignition switch is hooked up direct, so i assume that if i cut it near the ignition switch and splice in a wire to go thru the nss that the nss would work properly???

That should work if the truck is starting in gear ,and if the purple wire is carrying current to the solenoid, and not some other wire. It would be best if you can find the purple wire in the harness and cut it next to the NSS, then you wouldn't have to run extra wire.
Also be sure that the NSS is adjusted so that the contacts are closed in park and neutral. My truck was a standard trans so there is no NSS with the automatic I have now. I'll have to install one.



also if i ran a hot thru the back up light connector and to the reverse lights that should fix that problem. i don't know where the harness connects going back to the reverse/tail lights is, i will research that, but hopefully the wire to the back for the back ups is there..... i hate it when someone butchers something up!!!!!!!!!!!!!!!!

Look on the firewall just behind the distributor and there should be a plug with wires in it. That is the connector for the rear lights from the cab. It should have the tails and brake/turns as well as the green backup wire. The dark green wire is the right turn signal/ brake light wire.

Originally Posted by tonyr0774

Ok, an update.

As previously mentioned with my initial post the PO of my 68 K20 butchered the engine wiring harness. He cut all of the wires at the firewall connector with the exception of the coil wire. He performed a shoddy HEI conversion where he spliced a 12 gauge wire into the factory wire coming out of the connector. I cleaned that up by re-pinning it with a fresh 12 gauge wire. I re-pinned the following. Oil pressure sensor=20 gauge, coolant temp sensor=20 gauge, starter wire=12 gauge, brake sensor=16 gauge.

That's the clean way to do it. Good for you.


The triple aftermarket gauge cluster has gauges for the temp, oil and amperage. The amperage was never hooked up but my dummy light has always worked.

I'm not sure how the ammeter is wired in those. The water temp sensor is usually plumbed into the block just above the starter, and the oil pressure has the mechanical gauge with the plastic tube connector.


The oil has always and is currently working and the temp used to work but has not worked for some time now. The temp gauge is the type that I have to replace it with a new on that is a sensor, wire, gauge kit. I plan to do this and therefore the original BOSS on the passenger side of the block is and will be occupied by the gauge sensor.

In order to restore the factory lights I decided to purchase a water neck with sensor housing in it. The water neck is aluminum I believe. I purchased a new dummy light sensor, installed it into the new water neck and installed the water neck onto my aluminum Edelbrock intake manifold. The problem is now my temp light in the factory gauge cluster is on and I don't know why. I am fairly certain that my motor is not overheated as it never had any issues prior to restoring the warning light. I am also fairly certain that the thermostat I recently purchased was the correct temp=185 degrees I think. Is the fact that the manifold and water neck both aluminum maybe the cause? I would certainly hate to do away with the warning light considering the time and money spent on fashioning a brand new engine wiring harness.

You should be able to run the temperature warning light off the original sensor in the drivers side head. If the light is on all the time with the key on, either the sensor has gone bad or the wire is grounded at some place. Take the wire off the sensor and see of the light goes off, Key on of course. If it does then the sensor is grounding and you'll need a new one.

The aluminum water neck is not a factor. The sensor might be for a gauge and not the light, they are different so that might also be the problem. Again if you take the temp wire off the sensor and the light goes out then something is wrong with the sensor.

You probably know that the key switch also grounds the temperature light and the brake warning light when the key is placed in the start position. This is a feature the factory used to test the bulbs. They should go out when the key is returned to IGN OFF or ACC.




Also, years ago I installed one of those aftermarket brass proportioning valve. I never concerned myself with the brake sensor given the fact that the wire had been cut by the PO. Now that I have re-wired the harness with the factory plug I have discovered that the plug does not fit the proportioning valve sensor. I will provide some pictures tomorrow to give a better depiction of what I am talking about.

The aftermarket valve may be a different type and possibly don't have the warning light feature.

Any help would be greatly appreciated.

Thanks