Oil Pressure Gauge Mystery

[340gordy]

I have been playing "Whack-A-Mole" with the gauges on my Duster 340 for longer than I will admit. Started with some erratic operation on Temp and Oil pressure, pulled out the instrument panel, decided to replace all with new from Charger Spec. More erratic behavier, pulled out the inst. panel again
Note: (this does not get easier, the more times you do it) some of the needles were dragging, fixed that, tested all gauges with a 6 volt Lantern battery, all worked . acually this went on a couple of more times, but you get the picture, by this time my new dash paint has several new scratches.
This last time I replaced the sender for the oil pressure, plumbed in a tee, added an after-market mech. gauge. I ran the oil pressure up to 70#, still nothing on stock gauge! If I ground the wire to the sender, it pegs at the top. I put it back together and still same.
I'm not expecting solutions, just want you to share in my frustration.
Thanks, 340Gordy:banghead:

 

[67Dart273]

My first thought would be "bad sender" BUT when you ground a sender wire like that you are applying a LOT more "oompgh" to the gauge than normal. You might still have a sticking gauge and when you do that, you are causing the gauge to "unstick"

A "true" test would be to fire up the engine with sender wire unhooked, and test sender for resistance. If gauge sender reads low resistance, down around 10-15 ohms, at "full pressure" (engine running) consider the sender to be "good."

 

[RedFish]

If this is a rally panel.. I've said countless times, " DO NOT TAP ON GLASS ".
To do so will only breaks the melt stakes holding the bezel together. The lens and mating frame falls on the instruments. Their needle movement is extremely tender.
Sounds like you learned the hard way.
I can renew the OEM gauges and guarantee they'll work. I wouldn't want to play with those reproductions though. Those could have VDO parts or most anything inside.
Good luck with it.