Oil Pressure Switch? Extra wires - The 1947 - Present Chevrolet & GMC Truck Message Board Network

demian5 · 05-29-2019, 11:45 AM

So I have the engine and trans out and want to clean up the engine compartment. I have some extra wires i would like to clean up.
The truck had two temp senders, one in each head (both green wires), I don't know why. Both were hooked up.
There is a larger wire with a rubber spade plug type connector.
There is a 2-prong connector with 3 wires going to it.

And should my truck have a generator and oil pressure idiot light along with the gauges? If yes, where would the oil pressure switch be installed? I have the gauges.

I did some searching but didn't find anything, and none of the wiring diagrams had anything.

Could this be an AC harness?

Thanks.

rpmerf · 05-29-2019, 02:25 PM

Trucks with gauges have an oil line going to the gauge. It taps in around the distributor. I think you have lights for brake and generator.

Not sure on the AC harness, I can see what I have on my truck.

68 P.O.S. · 05-29-2019, 04:09 PM

The temp switch in the passenger side head is likely for the TCS system (transmission controlled spark). If so, you don't need it.

saxart · 05-29-2019, 04:14 PM

Quote:

Originally Posted by 68 P.O.S.

The temp switch in the passenger side head is likely for the TCS system (transmission controlled spark). If so, you don't need it.

My '70 had this crap system on it. Looked like a horn relay mounted to the firewall, and some extra wires. Ripped it out when the engine was out.

**HO455** · 05-29-2019, 04:17 PM

A PO has done some wiring which may be good or bad. These trucks only came with one temperature sensor. A temperature switch for an idiot light or a temperature sender (resistance style). If the PO just spliced a 2nd wire into the original it will have to be removed as the gauge will never work that way.
The PO may have added a switch and wiring to the idiot light to supplement the guages. This could have been done with the oil pressure to. If so the easiest place to attach a oil pressure switch would be to tee into the block where the factory guage line hooks up near the distributor or possibly at the back of the gauge.

demian5 · 06-03-2019, 07:13 PM

Quote:

Originally Posted by 68 P.O.S.

The temp switch in the passenger side head is likely for the TCS system (transmission controlled spark). If so, you don't need it.

Another question, will my temp switch in my head get a good ground with the aluminum heads? I have good grounds between the heads and cab, cab and frame, battery and block, batter and clip, frame and bed, block and frame.

**LockDoc** · 06-03-2019, 07:32 PM

Quote:

Originally Posted by demian5

Another question, will my temp switch in my head get a good ground with the aluminum heads? I have good grounds between the heads and cab, cab and frame, battery and block, batter and clip, frame and bed, block and frame.

Yes it will.

LockDoc

05-29-2019, 11:45 AM	#1
demian5 Registered User Join Date: Aug 2016 Location: Lake Forest, CA Posts: 2,177	Oil Pressure Switch? Extra wires So I have the engine and trans out and want to clean up the engine compartment. I have some extra wires i would like to clean up. The truck had two temp senders, one in each head (both green wires), I don't know why. Both were hooked up. There is a larger wire with a rubber spade plug type connector. There is a 2-prong connector with 3 wires going to it. And should my truck have a generator and oil pressure idiot light along with the gauges? If yes, where would the oil pressure switch be installed? I have the gauges. I did some searching but didn't find anything, and none of the wiring diagrams had anything. Could this be an AC harness? Thanks. __________________ "Work hard, use your vacation days." 1970 C15 GMC Long Bed 1986 C20 Scottsdale 1983 K2500 Sierra Classic Suburban 6.2 Instagram: C10sofOC

05-29-2019, 02:25 PM	#2
rpmerf Registered User Join Date: Feb 2011 Location: Parkville, MD Posts: 1,024	Re: Oil Pressure Switch? Extra wires Trucks with gauges have an oil line going to the gauge. It taps in around the distributor. I think you have lights for brake and generator. Not sure on the AC harness, I can see what I have on my truck. __________________ 1970 C20 Custom Camper - 350, TH350 1997 GMC Suburban 1994 Acura Integra GSR 1987 Dodge Daytona Shelby Z

05-29-2019, 04:09 PM	#3
68 P.O.S. Registered User Join Date: Jan 2007 Location: Puyallup, WA Posts: 1,662	Re: Oil Pressure Switch? Extra wires The temp switch in the passenger side head is likely for the TCS system (transmission controlled spark). If so, you don't need it. __________________ 72 C10 lwb fleetside -stock 350/350 combo

05-29-2019, 04:17 PM	#5
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 11,393	Re: Oil Pressure Switch? Extra wires A PO has done some wiring which may be good or bad. These trucks only came with one temperature sensor. A temperature switch for an idiot light or a temperature sender (resistance style). If the PO just spliced a 2nd wire into the original it will have to be removed as the gauge will never work that way. The PO may have added a switch and wiring to the idiot light to supplement the guages. This could have been done with the oil pressure to. If so the easiest place to attach a oil pressure switch would be to tee into the block where the factory guage line hooks up near the distributor or possibly at the back of the gauge. __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377



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