Oil pressure lamp stays on after installing restored instrument cluster

[440SportSatellite]

So I finally got my gauge cluster back from Auto Instruments a couple of weeks ago, and just got it installed this weekend. After getting everything back together and starting it up, everything seems to work fine, including the tach I had them install, which I wired up. The only problem is the oil light is coming on... I'm pretty sure it's a wiring issue, as when I disconnect the wire from the oil pressure switch behind the manifold and ground it out with the ignition on the light comes on as well. I tried to be careful and get all of the connections nice and tight on the circle connector at the back of the cluster... So I guess the question is, is it possible that it's an issue with the cluster itself and I'm going to need to send it back? Or is it more likely something I messed up when putting it in? The wiring harness in the car was replaced by a local shop when the 440 was dropped in, before I bought the car. I'm not really enthused about pulling the dash back apart to check all the connections behind the cluster, but I guess that's the next step. Any insight anyone here might have would be greatly appreciated.
Thanks!

 

[Pops1967GTX]

The oil light is turned on by an oil pressure sending unit. The sending unit provides the ground to the light when the oil pressure becomes too low. The sending unit is calibrated by the manufacturer but usually activates between 5-10 PSI. The oil light should come on with the key on and the engine off and go out shortly after the engine is started indicating proper oil pressure.

Check for a loose wire or ground on your gauge regulator........... Check Cluster not properly grounded to panel.

Trouble shooting Book...."To quickly test the voltage limiter in the vehicle, connect one lead of a voltmeter or test light to the temperature sending unit and the other lead to a good ground. Leave the sending unit lead wire attached to the sending unit. Turn the ignition switch to the "ON" position. A fluctuating voltmeter or a flashing light indicates the voltage limiter is operating."

http://www.allpar.com/history/mopar/electrical2.html


http://www.moparmusclemagazine.com/techarticles/interior/23241_instrument_gauges_repair/viewall.html

 

[bm02tj]

you answered your own question the light comes on when you ground it so check oil pressure with a manual gauge then replace sender

 

[440SportSatellite]

The info is much appreciated. The oil light has never lit up when turning the key on and starting the vehicle though... Not with the old cluster I took out, and not with the new restored one that I just put in. It doesn't light up until I start the engine.
I was under the impression that the fact it lit when I grounded the wire going to the sending unit meant that the problem was in the wiring and not the sending unit or the engine itself? I could be backwards about that though... I'd really love it if the problem was the sending unit and not something in the wiring. That would make it an easy fix.
Oh...this is all in a 1969 Sport Satellite with 440, just in case that matters.
I need to go get my multimeter back from my friend I let borrow it and test the the voltage limiter. It should be good as it was replaced when the cluster was restored though. I guess I need to get a manual gauge to put on and check the oil pressure as well.
Thanks again for the responses, it really helps to have some input from other people that have done this sort of thing before.

 

[bm02tj]

With the key on run does the light come on when you ground the wire going to the sender
if it does you have the wrong sender as it should be normally closed till you have oil pressure to open the circuit

 

[bm02tj]

just curious if you sorted the oil light problem out yet

 

[440SportSatellite]

just curious if you sorted the oil light problem out yet

I haven't had time to do anything with it so far this week. In the process of moving, so I've got a lot of other stuff going on. Luckily the Satellite is nice and safe in my fiance's garage so it doesn't have to move anywhere. I'm going to get a mechanical gauge to see what the oil pressure really is sometime this coming weekend and I went ahead and ordered a new sending unit switch from rockauto since it was only like $5 shipped. Hopefully that will fix the problem. Thanks for the help!

 

[bm02tj]

it sounded like you had a sender for a gauge

 

[copper67440]

Just my thoughts. The light comes on when its almost too late. Get an actual guage so you know what your pressure is.

 

[440SportSatellite]

it sounded like you had a sender for a gauge

Yeah, you're exactly right. After getting the new sender in the mail today and taking a closer look at the one that was on there, I did in fact have the sending unit for a gauge hooked up...I imagine whatever car that 440 came out of had a gauge and the guys doing the install just stuck it back on there not knowing the difference. After installing the new switch it works exactly like it should, with the light coming on with the key on, and shutting off once I start the engine. Borrowed a mechanical gauge my buddy had sitting around in his garage and the oil pressure is sitting right around 45 psi at start up, so I should be good to go. I'm so glad I didn't have to tear the dash back apart and look for a bad ground or wire somewhere.
Thanks again to everyone who replied for the assistance, it was a big help!

 

[bm02tj]

good to hear just for laughs get it hot then check pressure that will tell you more