Temp gauge posts? Which is which?

[7900_Blazer]

I need to direct wire this temp gauge, but need to know which post is ground, which is 12 volts, which is temp sensor…?

this issue standard’73 - ‘80 something temp gauge.

any direction much appreciated!

You must be registered for see images attach

 

[GMFORLIFE]

Try this

You must be registered for see images attach

 

[GMFORLIFE]

xc_hide_links_from_guests_guests_error_hide_media

 

[Allan Abley]

Got it..!!

 

[Tanked]

xc_hide_links_from_guests_guests_error_hide_media

 

[Tanked]

Great stuff but where is the sending unit on the Block I have it great stuff. But I have an 87 fuel injected can you show me where that sending unit is on the Block mine is not there?

 

[7900_Blazer]

Just wanted to give some feedback...

I was not able to make a new temp gauge work with direct wiring it... It seems it should be really simple... 12+, ground and temp sensor....

I tested the temp sensor against the one I have in my '71... and against the temp sensor that came in an aftermarket temp gauge - AND the temp sensor is brand new....

I could get the temp sensor to 'orient' correctly when turning on the key... but the gauge would not increase as the truck warmed up...

I tried pretty much every combination of wires-to-posts... nothing work... so I was forced to go back to my after-market temp gauge.

 

[GMFORLIFE]

Your gauge is bad then.
There are 2 types of sending units.
Idiot light just sends a signal to the hot light when temp gets above 220.
Gauge type sends different resistance to guage..so you get an actual reading.
If a second aftermarket gauge works but the other doesn't..the gauge is bad.

 

[Tanked]

I give up

 

[dsteelejr]

What year is that temp gauge supposed to fit? I’ve only seen stock and after market reproduction gauges with three posts.

 

[Tanked]

Never give up. Found the sending unit on a left side of the engine performed test found sending unit bad thanks everybody? still love this form

 

[7900_Blazer]

I've tested/used 3 different gauges... one brand new from LMC... so it has to be something else. The next thing I'm going to try is to double-check the sending unit... it's new too.... but maybe they gave me the 'idiot' light version of the sending unit... maybe it doesn't provide what an actual temp gauge requires.

 

[16927]

I had a similar issue with my temp gauge but it would go to hot when the key was turned on. Checked the sender wire for grounds, tried to pull wire off sender with key on tried another gauge, still no joy, so I spent some quality time with the wiring diagram and found that there were two sender wires, both the same color both with the same tip on that snap on to the sender. But in two different locations, And one was on the sender and other was plugged into the carb for some reason. Unplugged that and it was fixed.
So how long have you had this truck? And has the factory gauge ever worked? Does it have the factory oil and volt gauges and do they work?

study the wiring diagram and see if the wire you have connected is the right color wire that the diagram calls for, mine is a dark green.

Don’t know if this helps or not but sounds like you have to get back to the basics.