[Wedg3]

I put a water temp sensor of a FJ40 81 and the pressure sensor of a fj40 1975. I keep my factoyry 24 volts cluster... Did I do somethings wrong ? I try to find at toyodiy.com the part number to know if all if ok.. but I didn't find answer

[Tobugrynbak]

I've checked my Factory service manual regards the differences between 12/24volt instrumentation.

It seems they use the same senders and instruments. There is a dropping resistor on the back of the cluster which drops the voltage from 24 to 12 volts and is then fed to the instruments voltage regulator.

What problems are you having?

[Wedg3]

The problem that I have is my pressure sender unit that work but the pressure isn't good. The max pressure with a mec gage tell me 80 psi, the normal 60 and the max low pressure 35psi. So every LC guy know that the idle pressure is as low as 5psi... In a long run my pressure is 30psi. so I don't even see the needle on the gage.

For the water unit all is ok, but just want to know if the temp is good or not

[roscoFJ73]

How many miles has the engine done?

[Wedg3]

The engine is fresh rebuild. The pressure sensor is new and the water sensor to.

[Tobugrynbak]

Have you tried swapping in your old oil pressure sender?
When you put the thread tape on the sender, did you block the tiny hole?
Is your truck still 24 volts? If you've converted to 12 volts you will need to remove and bypass the dropping resistors on the back of the cluster.

You may also have a gauge issue, it happens on older vehicles. You may fix the big problem, but its all the extra little ones that get you.