'88 K5 guages

[kentuckyblazer]

So I recently traded my old truck for this 1988 k5, the gauges all had broken needles so I replaced the alternator gauge, temp gauge and oil pressure gauge with ones from LMC. The alternator works fine but oil is always maxed, temp is always minimum. Tried changing sensors, cleaning grounds the usual stuff.

At a loss currently for how to solve

 

[dyeager535]

So I recently traded my old truck for this 1988 k5, the gauges all had broken needles so I replaced the alternator gauge, temp gauge and oil pressure gauge with ones from LMC. The alternator works fine but oil is always maxed, temp is always minimum. Tried changing sensors, cleaning grounds the usual stuff.

At a loss currently for how to solve

Verify there is even a sender for the oil pressure on the engine. TBI uses both a two wire (switch for fuel pump) switch and single wire (sender for gauge) sender, if the sender isn't plugged in/present it will react that way.

After doing the visual inspection/confirmation...

If you've already had the cluster apart, take the gauges back out (leaving the cluster in place) and check for continuity on the sending unit wires all the way to the applicable sending unit. Oil pressure should be an open sending unit wire (not connected properly, broken wire, etc) and you'll need to check for proper voltage/ground on the appropriate "terminals" in the cluster housing for the coolant temp.

When you are in there, check that both gauges have good voltage and ground, as that is a common problem due to the flex circuit on the back of the cluster.

 

[kentuckyblazer]

Got everything all solved luckily, bad temp sensor on the driver head, checked with Ohms, and ground was disconnected on the back of the block by the trans dip stick tube which made oil pressure work