73 electric gauge in 71 dash cluster
 

Edit: It's actually a 78-79 electric oil gauge in a 1971 K10. I think I have the wiring correct now but perhaps the ADO-D8034 sending unit is the wrong sending unit.

Hi. I've put an electric gauge in my 67-72 dash cluster. I assume 1 post in negative, one is positive, and the other is for the sending unit. I thought about trying random setups but felt I should get advice first.

Re: 73 electric gauge in 71 dash cluster
 

Temp gauge I presume.
Look up the 1973 wiring diagrams. The cluster layout is on the first page of diagrams.

Re: 73 electric gauge in 71 dash cluster
 

Sorry, it's the oil gauge. Thanks for the link. It looks like based on the manual, the ground is in the middle.

Re: 73 electric gauge in 71 dash cluster
 

I found this picture in another thread. Someone trying to work out the same question.

Re: 73 electric gauge in 71 dash cluster
 

Here's my current setup. The brown is ground. Pink is 12v. I don't see colors very well so I'm guessing that's pink. My blue is the sending unit wire. The oil is showing running high. I bet that's not accurate. If I flip the 12v and sending wire it sends the needle all the way to high past 60.

Re: 73 electric gauge in 71 dash cluster
 

I'm using an ACDelco Oil Pressure Sending Unit that I realized today doesn't list 78-79 c10 as a fit. It does list 1977 https://www.summitracing.com/parts/A...4/applications

I am using a gauge for 78-79 c10 https://www.lmctruck.com/1973-91-che...pressure-gauge

Is it reading high because I bought the wrong sending unit?

This one shows a 78-79 c10 as a fit https://www.summitracing.com/parts/s.../c10/year/1978

So maybe the make and model of the vehicle doesn't matter in relation to the engine dictating what sending unit to use but instead, the make and model of the vehicle dictating what sending unit to use per the gauge that was in that make and model?

Re: 73 electric gauge in 71 dash cluster
 

That oil pressure is a near match for what my 75 with a stock 350 shows when at speed. OEM mechanical gauge. Disclaimers - sample size of 1 and ~48 year old gauge.

Re: 73 electric gauge in 71 dash cluster
 

My value was at idle 3 minutes after starting it. So it might be accurate?

Re: 73 electric gauge in 71 dash cluster
 

Mine is the same cold. Once hot, the at idle pressure is lower but goes back to that when I rev it a bit. The motor has about 110k miles on it.