Temperature and oil gauge

[84stepside]

Good morning. I have an 84 Chevy Silverado Stepside with a 305/ TH350, electric choke that is having difficulty getting a reading at the gauges.

Things I’ve done
- changed temperature sending unit single spade connector
- changed fuse idle/gauge 20 amp
- tested wire for temperature sending unit to ground and gauge goes to full hot
- I have the oil pressure sending unit (single spade) connector but haven’t changed yet.
Traced wiring which is interesting in comparison to all the threads I have read here.

Pictures of what the wiring looks like.
Pic 1 - blue and green wire that come from inside the cab but green isn’t connected to anything. These 2 wires are connected to these 2 brown wires and one is free and the other connects to oil pressure sending unit next to distributor.
Pic 2 - location of where blue/green wire goes through firewall
Pic 3 - bulkhead wires wondering if I can just run the gauges/ sending units directly from here with more success?
Pic 4 - looks like I have oil sensor 3 wire.
Pic 5 - orange connector in middle is the open end of the green wire in the cab. Blue wire goes up behind dash..haven’t gone up to see what it goes to yet.

Thank you for any assistance. I know this topic has been covered and I have read a ton of threads but this seems to me slightly different than any other thread read so far.

 

[Chuckd84]

Ive had issues with oil pressure readings caused by the circuit board behind the dash cluster. The bulbs for lighting the guages caused some heat damage over the years. Have you checked in there yet?

 

[84stepside]

Actually just took the cluster out to put LED lights for the cluster. I didn’t see any burning or shorting of the circuit board. All the lights light up too. It’s a possibility but think it’s more wiring from the bulkhead then anything but I’ll check that tomorrow and update.

 

[bucket]

The oil pressure switch down by the oil filter is just for the electric choke circuitry and the choke light in the cluster. Is that system not working?

The oil pressure sender by the distributor is for the gauge. You can test the circuit the same way you did with the temp circuit.

As for your temp gauge issue, you either got a dud sender, or possibly you inadvertently bought a temp switch and not a sender. I suppose it's also possible that you are missing an engine-body ground.

 

[84stepside]

ultimate face palm…looked up the senders and found out both were lights and not gauges. Changed to sending units for gauges and now it all works.

 

[84stepside]

Thank you everyone for the feedback. Great info.