Author Topic: Temperature sending unit  (Read 174 times)

Offline Postess89

  • Newbie
  • Posts: 8
  • Newbie
Temperature sending unit
« on: May 24, 2020, 04:54:15 AM »
Hey guys. I'm having some trouble finding the information online so I'm hoping someone here can impart some knowledge. I have a 76 k10 with a 5.7L 350. When I had the engine rebuilt a few years ago the temperature gauge in the cluster didn't work so I had a cheapo aftermarket from autozone put in. The kind that isn't meant to go into the original cluster but rather mounted above or below the dash. Well since then I've replaced the broken gauge in the cluster but I can't figure out how to wire a temperature sensor to it. I understand where the sensor screws into the engine, but where does the wire go to? I'm a novice when it comes this so I appreciate any and all help. 

Offline bigben5054

  • Newbie
  • Posts: 95
  • Newbie
Re: Temperature sending unit
« Reply #1 on: May 24, 2020, 07:25:41 AM »
Someone may correct me, but...I think your factory water temp gauge would have been electric and I would guess your aftermarket gauge was mechanical.  For the original electric gauge, there would have been a wire connected to the sending unit that went into a wiring loom, through the firewall and eventually into the large connecter that plugs into the back of the gauge cluster.  Any idea what they did with the wire when they installed the aftermarket gauge?  Have any homeless wires laying around the engine compartment?

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 5652
Re: Temperature sending unit
« Reply #2 on: May 25, 2020, 12:52:44 AM »
The simplified diagram below illustrates where the factory coolant temp wire connects to the sender and the instrument cluster connector, as well as where it passes through the firewall bulkhead connector.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Postess89

  • Newbie
  • Posts: 8
  • Newbie
Re: Temperature sending unit
« Reply #3 on: May 25, 2020, 10:54:54 AM »
Thanks a bunch guys. I looked for a homeless wire but didnt see anything. That diagram just worked nicely! Thanks for walking me through it.

Offline jgcusmc

  • New Users
  • Posts: 1
  • Newbie
Re: Temperature sending unit
« Reply #4 on: May 28, 2020, 08:53:22 AM »
If the gauge is electric, there should be a block sending unit with brass adapters. There should be five wires, one for the sender, one for positive connection for power to the gauge, one negative for the gauge power, and two wires for the backlight.