Strange Electrical Problem?

[hadley000]

Hey All,

I'm at my wit's end, again. I've been working on my 94 IDIT getting ready for Summer since I have some downtime waiting for the mud to dry up. So, I put in a new radiator core support, radiator, trans cooler, and condenser for the A/C.

Now my oil pressure gauge reads zero at idle but normal when on the accelerator, I have no heat but the fan works, the A/C clutch wants to stay on even when the heat is selected, the engine temp light comes on and the temp gauge is pegged. Everything else seems to work normally, and everything wrong now worked normally before doing any of this work. But, the A/C hadn't worked before fixing the condenser so it couldn't be used.

I've tracked down every connection I can find and inspect/clean it if need be, but nothing changes. I disconnected the low-pressure A/C switch to disable the A/C, but still no heat. All the grounds near the driver's side battery have been reconnected. The truck doesn't overheat, and the radiator hoses seem to be normal temps.

Any ideas on where to start looking?

 

[Thewespaul]

Disconect the wire on the oil pressure gauge and see if the gauge still bounces around. If it does then the trouble is in the wiring, if it doesn’t I would suspect a bad ground or bad sensor, since you have numerous issues going on electrically I’d lean towards a grounding issue. Considering what circuits you’re having issues with, I would check out ground G200 first. This will be a black wire with a white stripe going on the firewall inside the cab near the ac ducting area on your 94.