I have SW gauges and sending unit. I was running the stock Ford sending unit and it was reading high so I ordered a SW sending unit designed for the gauge and I get no reading. How can I test the sending unit to see if it's bad? Should it be putting out a certain voltage or ohms? What range should I be reading? Thanks.
How do I test an oil pressure sending unit?
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Your Ford sending unit was most likely not pressure sending unit but a idiot light switch. Apply power to the gauge(turn Ign. on)and ground the wire to the sending unit. You should get a full scale reading.If this happen you should check the ground on your sending unit or replace the sending unit.The sending unit should have the same range as your gauge .Most likely no power or no grounding somewhere.
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I grounded the gauge as described. I turned on power and verified 12 volts to the plus post on the gauge then touched a grounded wire to the sending post on the gauge. Nothing. It just sits there looking useless. 
Does that mean the gauge is bad? Or could I have some other problem.
I used teflon tape on the sending unit and in looking for answers noticed the instructions say not to because it needs to ground. I did a continuity check from the base of the sending unit to the intake manifold and it checked out so I'm sure I'm OK there but just wanted to give as much info as possible.
I bought these gauges from someone and they were still in the boxes but had been opened. So far I've had to replace the tach and as if that didn't make this already a really bad buy, now if I've got to replace another one.
Please tell me there is another answer! Pleeeease
Does that mean the gauge is bad? Or could I have some other problem. I used teflon tape on the sending unit and in looking for answers noticed the instructions say not to because it needs to ground. I did a continuity check from the base of the sending unit to the intake manifold and it checked out so I'm sure I'm OK there but just wanted to give as much info as possible.
I bought these gauges from someone and they were still in the boxes but had been opened. So far I've had to replace the tach and as if that didn't make this already a really bad buy, now if I've got to replace another one.
Please tell me there is another answer! Pleeeease
Sure sounds like a guage problem. I would do one last check before changing the guage out. Power up the guage as done before and use your ground jumper on the guage directly. this will show if the guage or the wiring to the guage is at fault.Mechanical guages are good choice's for oil/ water .See if you still have a warranty on your guage. Put a oil filter directly on the engine for safety while working on this problem. Remote oil filters can cause all kind's of strange problems.
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