Oil pressure gauge help needed

[JTL]

The gauge in my car is pegged at 5 bar. There is no change when wire is unplugged from the sender. How is the wire run directly from the sender to the gauge or is there a multiwire plug/connector somewhere in between?

Thanks, jt
-84 targa

[JTL]

I poked around the engine comp and found that the green wire with red stripe is wired to #4 pin on the multipin connector on left side of comp by the relays. My meter indicates conductivity from the sender to gauge yet the gauge pegs as soon as ignition is turned on. I'm now thinking there is something wrong with the gauge?! Opinions please.

jt

[Diesel_mp5]

Power runs from the gague to the sender and grounds there. You sound like you have a stuck sender... Smack it and see what happens.

[JTL]

The op gauge pegs when I turn the ignition on but drops back to 0 after turning the key off. Sometimes I have to tap the gauge for the needle to drop. So far I know there is no open loop from gauge to sender. I have to check the gauge ground and if that's good the gauge must have gone tu. All other gauges work ok.

jt

[jstobo]

I do not have my reference material with me and I do not remember which way the pressure gauge works. (Temperture gauge is usually opposite of pressure). But a pegged condition indicates either a grounded signal wire or an open connection. Pull the signal wire from the gauge to see if there is a change. If so then you have a bad connection. If no change ground the signal connection at the gauge, needle should move if the open position did not move the needle, if no movement gauge is probably faulty. If the p gauge zeros when you unplug the signal wire, do the ground test then it should peg. Which mean you have a gounded signal wire. I hope all this is clear as mud. As i said I forget which way the gauge shoiuld peg on open and grounded conditions. Good Luck

JIM

[rlane]

There have been recent threads on a full diagnostic for this, try a search for oil pressure gauge.

[JTL]

Thanks for the tips. I'll try trouble shooting the gauge tonite.

BTW Jim, I used to live in Wilmington! I went to grad school at uncw and after graduation in 2000 my wife got homesick. As a result we have been in 'beautiful' nw Indiana for the past 4 years. I would love to get back to the southeast!!

jt

[JTL]

The gauge pegs independent of the signal wire when ignition is switched on. That means the sender and wire are ok?

The gauge drops to 0 when signal input is grounded.

There are 3 posts back of the gauge. Looking at it from the top I have red/w black strip at 9 o'clock, green/w red strip (signal) at 3 and nothing on the bottom 6 o'clock position terminal.

Should there be a wire on the bottom terminal? So far I'm coming up with a gauge problem??

jt

[Diesel_mp5]

Hey this might help... Hope you can read it.

[jstobo]

Your gauge is fine. It pegs correctly for open and ground according to my references. The green/black is the oil temp signal the gr/rd is oil pressure. Now check wire continuity for your gr/rd signal wire. Disconnect from sender and check resistance to wire at back of gauge. Should be 0 ohms or very little. If wire is okay then the sender is bad. My guess is since your gauge pegged high you probably have an open circuit in your signal wire. Or maybe dirty 14 pin connections. The senders are pretty rugged. But it could be the sender so check that wire.

Spring is not quite here yet. Keep getting cold air from you northern types. But getting close. Fortunately I married a Southern Girl 26 years ago and will not have to worry about moving north. Good luck on your testing.


Jim

[JTL]

Wire from sender to gauge reads 0.5 Ohms. I cleaned the 14 pin contacts are gauge still pegs. I would not have though the sender is bad. It was replaced - - - hmmm, guess it's been a few years but I remember doing it during my 8 years of ownership. I can prolly borrow a sender from one of the p-car nuts around town for a check. Thanks Jim and guys.

Eventhough we are up here in the north the temp has been 70-80 for the last couple of days. The azaleas should be fixin' to bloom down there in ILM.

jt