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Post by gitrdun on Jul 15, 2012 13:29:53 GMT -5
My oil pressure gauge is not working properly and hasnt since ive had the car. When i turn the key on the gauge pegs out. Even if i unhook the wire from the sending unit the gauge pegs out. The gauge and the sending unit both have VDO on them as the mfg so i assume they are a match set. Do i have a ground problem, or a bad sender? I dont know how these electric gauges work, should i have voltage on the gauge wire or is it a ground?
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Eric A
Full Member
It's an obsession not an investment!
Posts: 223
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Post by Eric A on Jul 15, 2012 15:22:49 GMT -5
It really sounds like a ground problem. You should have a power, ground, and sending unit. Either you have a bad gauge or you have a bad ground.
Eric
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Post by jspbtown on Jul 15, 2012 16:33:47 GMT -5
The sending unit uses a variable ground signal. A meter will tell you if you have power where you should have power, whether you have a ground where you should have a ground, and then continuity with the sending wire. Lots of good things here: www.egauges.comI would check for proper wiring and make sure you have no sealant on the sending unit. |
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Post by Dan MacMillan on Jul 15, 2012 21:14:02 GMT -5
Disconnect the sending unit wore at the gauge. If it still pegs it is the gauge. Odds are it will stay at zero, indicating a grounded sending unir wire. If it drops to zero trace the sender wire it locate the short to ground, or run a new wire.
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Post by gitrdun on Jul 17, 2012 19:57:27 GMT -5
I disconnected the yellow signal wire on the back of the gauge and it still pegs out. I didnt think to check to make sure if it has good ground or not. Its 102* out today and i had to give up before my body gave up.
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Post by quentin on Sept 18, 2021 20:38:37 GMT -5
Did you ever correct your VDO gauge problem? Some answers here (and a similar question in a 914 forum) are not quite correct. Yes, you need a ground wire, especially in a fiberglass car with plastic panel for gauges. BUT... your SENDER wire in a way is operated when the sender is fully grounded internally by NO oil pressure. Partial grounded to read various pressures thru a wound wire like a gas tank sender. But to have it work the metal bracket of the gauge (U shaped with 2 nuts) MUST be grounded to the chassis. Make secure ground wires for everything that would normally be grounded to the metal body in a more conventional car.
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