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+--- Thread: VDO Fuel Gauge Sending Unit resistance. (/showthread.php?tid=4904)
VDO Fuel Gauge Sending Unit resistance. - kayej@cox.net - 10-06-2017
The standard 30-230ohm sending unit does not work correctly. Gauge pegs when key is turned on. These units are in a 1984 Tiara Open express with gas engines. Bought the boat and both fuel gauges were either fixed (1/4 tank) or didn't work at all. Tried the Moeller (universal) units and they apparently do no work with the VDO gauges installed in the boat. The old sending units were Tempo R202 but I cannot find a replacement for them. Any suggestions would be greatly appreciated. Thanks
RE: VDO Fuel Gauge Sending Unit resistance. - jclark003 - 10-14-2017
VDO has a lot of different sending units that are matched to the gauge. Some of them are backward in relation to the standard US 240-33 ohm (example 10-184).
I would first check the sender resistance at the helm(disconnected from the gauge) to make sure the wire isn't shorted to ground. Then I would ground the sender terminal and see which direction the gauge moves. If it travels to full then it is probably 240-33 and you have a sender or wiring issue. If it travels to empty your gauge is probably matched to a different resistance range. If this is the case it might be easier to replace the gauge since you already have a new sender.
Good luck
RE: VDO Fuel Gauge Sending Unit resistance. - kayej@cox.net - 10-16-2017
Thanks for the tips. Will give it a try.