78 k10 temp and oil sender mess.

[mufwapo]

I saw the post about the 87 tbi and I thought perhaps someone would have more info on my problem. I have a 78 k10 with the original 350, but the PO installed aftermarket mechanical gauges that don't work and I'm trying to hook up the factory gauges instead. I bought both senders from advance auto a few days ago but I can't find the factory wires to hook them up to. Does anyone know where these would come out of the firewall at? Also about center in the drivers side of the block is where the mechanical temp sender is located but it's too small of a hole the thread my sending unit into, is there some other place the factory sending unit was installed? Any help would be appreciated as I'd like to get these hooked up before something bad happens. thank you!

[Prong]

The temp sender goes in the head on the driver's side. That should be a green wire. The oil wire should be a beige/tan color. They both should come out of the square junction block below the wipers.

[motornut]

i just changed from idiots to factory tach & gauges in my 78 jimmy below might help sort it out

[raws67]

check out the tech tips on the main page. There is some good info on wiring. As for the temp sender keep in mind there is 2 different sizes that were used. I ran in to this problem before. I ended up buying a sending unit for an 84 and my truck is a 78. The 84 sending unit was the smaller diameter. As far as I know all of these temp gauges use the same resistance sending units. I will have to check on exactly where the wires are routed through the firewall. Good luck

[mufwapo]

Originally Posted by raws67

check out the tech tips on the main page. There is some good info on wiring. As for the temp sender keep in mind there is 2 different sizes that were used. I ran in to this problem before. I ended up buying a sending unit for an 84 and my truck is a 78. The 84 sending unit was the smaller diameter. As far as I know all of these temp gauges use the same resistance sending units. I will have to check on exactly where the wires are routed through the firewall. Good luck

I think I found the wires, there's only one spot for a sending unit on the drivers side head that I found but it is the smaller diameter so I'll pick up a sending unit for an 84 tonight. It's right between the #1 and #3 cylinder exhaust ports. Thank you all very much for this info!