Author Topic: Temperature sensor and other wiring HELP  (Read 3264 times)

Offline 77chevystepside

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Temperature sensor and other wiring HELP
« on: June 21, 2009, 07:11:01 AM »
Just when I thought I knew what I was doing I get confused. On the 350 engine does it matter where the temp sensor is installed. Three plugs-one by thermostat housing and one on each side of the block. I could not remember where mine was so put it by thermostat housing thinking I have less risk of burning the wire there than in block holes by exhaust. Looking at the pictures I took before tear down, I did not have it in thermostat housing hole nor drivers side block so must have had it in pass side block hole. Does it matter?
Also, I have a brown wire coming out if the firewall by itself on the fender side and just below the brake booster. It is about a foot long with a factory connector. What does that wire go to?
I am planning to trace the brown wire into the cab and hope to learn what it goes to but would advice on the temp sensor as well as the brown wire. Thanks

Offline baddogg79

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Re: Temperature sensor and other wiring HELP
« Reply #1 on: June 21, 2009, 08:52:23 AM »
I dont think it matters. On my 73 its on the driverside of the engine. I also have one on the intake for my electric fan set up. I think as long as its in the water jacket, you will get about the same readings. As for the brown wire, ill take a peek at mine when I can.

Edit, thats what I get for wake and posting lol, wrong place :P
« Last Edit: June 21, 2009, 09:10:02 AM by baddogg79 »

Offline VileZambonie

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Re: Temperature sensor and other wiring HELP
« Reply #2 on: June 21, 2009, 09:21:24 AM »
Do you mean the coolant temp sending unit or do you have a coolant temp sensor for the computer? what year truck are we talking here? The ecm sensor is next to the t-stat. The coolant temp sending unit is in the drivers cylinder head.
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Offline 77chevystepside

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(SOLVEDTemperature sensor) Still need wiring HELP
« Reply #3 on: June 22, 2009, 06:38:49 AM »
Coolant temp sending unit on 77 350. I decided to move it to drivers side head because the top of the wire and sending unit were rubbing the thermostat radiator hose. 

I am pretty certain the brown wire coming from the cluster through the firewall is a ground wire that plugs into distributor. It was one of three wires in a plug that plugs into the cluster and it is labeled ground.