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tonyr0774 · 10-24-2014, 04:37 AM

Hey fellas,

Hoping a few of you can impart a little wisdom. I am in the process of cleaning up the butchery the PO of my 68 K20 inflicted on the wiring. While tracking down the problem with my reverse lights I replaced the NSS and discovered that the starter portion had been by passed. The PO had unplugged the dual green wire connector and jumped the starter wire directly into the hot wire. I have since attempted plugging the dual green wire connector into the proper prongs on the NSS while connecting the starter wire to the 12 gauge purple wire from the top connector on the firewall.

The result is a little perplexing in that the starter does not turn, however when placing a tester light on the connection while having someone turn the key the light turns on. When I wire it directly back into the dual green wire connector (after unplugging it from the NSS of course) the truck starts right up....in any gear of course! I cannot figure out why I would get a positive reading from the firewall connector but no start. The PO also cut all of the sensor wires from the firewall top connector meant for the temp, brake and oil warning lights and installed aftermarket gauges.

I am in the process of re-pinning the connector head but am again perplexed. With all of the corresponding sending unit warning light wires cut shouldn't the temp, brake and oil lights be on? They currently are not and have never been since I've owned the truck. I have already checked to see if they had removed the bulbs on the gauge cluster and all but one are intact....cant remember which one is not. Do all of the warning lights need to be in intact to complete the circuit for all to work when they are supposed to? (its funny, this possibility just came to me as I was typing this).

Finally, a two part question. What is the type of silicone used by the factory to seal the harness connectors or a good, safe equivalent. I'm thinking just RTV silicone. I want something that remains soft and pliable. Preferably something even more pliable than RTV silicone. And if I decide to replace my gauge cluster with the later model that has the gauges rather than dummy lights what all is entailed and how much of a PITA is changing the cluster harness if that is all that is needed besides the changing of the sending units?

Any help or feedback would be much appreciated

10-24-2014, 04:37 AM	#1
tonyr0774 Registered User Join Date: Oct 2014 Location: Granger Posts: 12	Wiring Help Hey fellas, Hoping a few of you can impart a little wisdom. I am in the process of cleaning up the butchery the PO of my 68 K20 inflicted on the wiring. While tracking down the problem with my reverse lights I replaced the NSS and discovered that the starter portion had been by passed. The PO had unplugged the dual green wire connector and jumped the starter wire directly into the hot wire. I have since attempted plugging the dual green wire connector into the proper prongs on the NSS while connecting the starter wire to the 12 gauge purple wire from the top connector on the firewall. The result is a little perplexing in that the starter does not turn, however when placing a tester light on the connection while having someone turn the key the light turns on. When I wire it directly back into the dual green wire connector (after unplugging it from the NSS of course) the truck starts right up....in any gear of course! I cannot figure out why I would get a positive reading from the firewall connector but no start. The PO also cut all of the sensor wires from the firewall top connector meant for the temp, brake and oil warning lights and installed aftermarket gauges. I am in the process of re-pinning the connector head but am again perplexed. With all of the corresponding sending unit warning light wires cut shouldn't the temp, brake and oil lights be on? They currently are not and have never been since I've owned the truck. I have already checked to see if they had removed the bulbs on the gauge cluster and all but one are intact....cant remember which one is not. Do all of the warning lights need to be in intact to complete the circuit for all to work when they are supposed to? (its funny, this possibility just came to me as I was typing this). Finally, a two part question. What is the type of silicone used by the factory to seal the harness connectors or a good, safe equivalent. I'm thinking just RTV silicone. I want something that remains soft and pliable. Preferably something even more pliable than RTV silicone. And if I decide to replace my gauge cluster with the later model that has the gauges rather than dummy lights what all is entailed and how much of a PITA is changing the cluster harness if that is all that is needed besides the changing of the sending units? Any help or feedback would be much appreciated