[carbuff]

At key on, engine off, the oil pressure gauge pegs on my '88 (VDO gauges). -eek-

Should read zero.

Even when the Oil Pressure sender is disconnected, it pegs.


Does the gauge read higher with MORE resistance, or LOWER with more resistance?

If the first scenario (meaning I have a duff sender or open wire), can I connect the sender wire to ground without blowing anything out? :facepalm


Will be checking continuity tonight or tomorrow...

 

[Vulcan Grey]

probably wiring, an open somewhere.

 

[Extratx]

The connectors on the engine for the no pressure light, and for the pressure sender, are right next to each other. Perhaps you got them backwards? Pretty sure it reads no pressure if the wire is disconnected / open connection.

 

[carbuff]

The connectors on the engine for the no pressure light, and for the pressure sender, are right next to each other. Perhaps you got them backwards? Pretty sure it reads no pressure if the wire is disconnected / open connection.

Then I have a short. Getting 12 ohms on the white/brown wire when disconnected at the EHC (Engine Harness Connector, under the header tank).

At least I managed to take pics of the wire positions for these components. They MIGHT be backwards (I'm quite capable of that type of goof)...but if I should read zero at the gauge with the harness disconnected, I'm shorted. <sigh>

 

[jtrealty]

By all means, you need to fix the gauge problem but on an initial start I like using a good, old fashioned, mechanical pressure gauge. That way I KNOW what is going on. Most electric oil pressure gauges will peg on low resistance to ground. Pull the sender wire at the gauge in the binnacle and see what happens. Chances are you got the other end by the motor either on the wrong spot or maybe the wire got pinched somewhere.
David Teitelbaum

 

[carbuff]

Update: Problem solved.


I found the pictures I took before disassembly of the engine. Hooked up the wires as pictured, verified that the EHC was fully together, and VIOLA! At key-on, the oil pressure needle just moves off it's resting place, and indicates zero. Just like it oughta.


I attached the pictures below in case anyone needs a reference in the future.


Pic are: sender and oil temp switch disconnected. Hookups of oil temp switch and sender. Views are from over the transmission, facing forward.

 

[lotus4s]

Atwell,

So what was the problem?

Jim

 

[carbuff]

Hi Jim,

Might have been an improperly positioned wire (wrong terminal) or loose EHC.

Once the problem was observed, my helper ripped all the wires off the sender and oil temp switch. Arrgh. :facepalm So, it was unclear where they belonged.

My original tags had been removed by that time and we tried to look at the electrical schematics to hook up the wires but we were unable to find a way to I.D. which terminal was which, especially on the sender.

Only took about 20 minutes to search through all the pictures I had taken and find the original configuration...

That's why I posted the pics...might help someone in the future. :up:


(OR...I could blame everything on that leaf in the pictures, I dunno.) rotfl