Can't find my temperature wire - LS Swap

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

ih8vols

Junior Member
Joined
Aug 31, 2019
Posts
18
Reaction score
10
Location
TN
First Name
SC
Truck Year
1979
Truck Model
C10
Engine Size
2002 LS1 4.8
I just completed an LS swap on my 79 C10 stepside. Even though I'm only the 2nd owner of the truck, it's obvious the old owner tried various wiring changes because some of the wiring makes zero sense.

The new engine is firing up and running great. The only thing not working yet is my temperature gauge. My new engine has a 3 wire pigtail at the temp sensor coming out of the core - 2 wires that run to the ECU and one (green) that should run to the dash gauge.

The temp sensor worked on the old engine. I just can't find the wire for the gauge. I did not remove any of the old wiring during the swap. All the wires that aren't being used are zip tied under the hood.

Does anyone have a picture of the connector that is plugged into the motor on the original engine? I think that might help me locate the wire.

The only wire that looks like it might be the one I need is in the pictures below. It's dark green and runs into the block head on the driver's side of the truck. This this is it?

Appreciate your help!


https://drive.google.com/open?id=0B0PZQ2m9_AniZXRyNWo1RFZFaXJGVWV1X3Fvbkw5MDI3T1I4

https://drive.google.com/open?id=0B0PZQ2m9_AniLWJzd25jTTV0QXR6RkNVaHpHd3F4YmpWc3JN
 

Charlie

Mopar by Birth. Chevy by Choice.
Joined
Aug 2, 2017
Posts
1,837
Reaction score
912
Location
Euless, Texas
First Name
Don
Truck Year
1974
Truck Model
Cheyenne 10 LWB
Engine Size
350/TH350/AC/4 BBL Quadrajet
:welcome:
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
30,446
Reaction score
28,349
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
Its normally a spade type of connector that slides onto a round post on the sender. But that is the right color wire. Was the truck a 6cyl?

Does the gauge move if you ground out the wire?
 

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,266
Reaction score
2,210
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
The wire in your picture does not look like my '75's temp wire or any other wire on my truck. Its similar to the plug on the A/C low pressure switch, but that has two connectors inside.

The temp sending unit wire is green, and has one of two types of connections. My '75 has a button or "nail head" on the end of the temp sending unit like this one. https://www.repairconnector.com/products/GM-Single-Wire-Coolant-Temperature-Sender-Connector.html The wire has a plastic connector with a slot in the end, and it slides on at a right angle to the button. When you slip it on the button this makes the wire point straight up from the sending unit screwed into the head. The last 6-8 inches of the original wire has a black fabric heat protector around the wire to protect it from exhaust manifold heat. Some GM sending units have a standard spade connector on the end instead of the button.

Bruce
 

C10MixMaster

Full Access Member
Joined
Dec 6, 2016
Posts
756
Reaction score
1,424
Location
Kingman AZ
First Name
Ben
Truck Year
1977
Truck Model
C10 BIG10
Engine Size
ZZ4 350
I just completed an LS swap on my 79 C10 stepside. Even though I'm only the 2nd owner of the truck, it's obvious the old owner tried various wiring changes because some of the wiring makes zero sense.

The new engine is firing up and running great. The only thing not working yet is my temperature gauge. My new engine has a 3 wire pigtail at the temp sensor coming out of the core - 2 wires that run to the ECU and one (green) that should run to the dash gauge.

The temp sensor worked on the old engine. I just can't find the wire for the gauge. I did not remove any of the old wiring during the swap. All the wires that aren't being used are zip tied under the hood.

Does anyone have a picture of the connector that is plugged into the motor on the original engine? I think that might help me locate the wire.

The only wire that looks like it might be the one I need is in the pictures below. It's dark green and runs into the block head on the driver's side of the truck. This this is it?

Appreciate your help!


https://drive.google.com/open?id=0B0PZQ2m9_AniZXRyNWo1RFZFaXJGVWV1X3Fvbkw5MDI3T1I4

https://drive.google.com/open?id=0B0PZQ2m9_AniLWJzd25jTTV0QXR6RkNVaHpHd3F4YmpWc3JN


green should be the correct color. the wire end your showing looks like a oil pressure sender connector

You must be registered for see images attach


this is the typical sensor and connector
 

Forum statistics

Threads
44,173
Posts
950,829
Members
36,287
Latest member
goodwrenchca
Top