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Oil pressure sender wiring schematic?

Dave2000

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spain
Hi, up in the mountains today pootling along minding my own business and noticed the oil pressure gauge was reading nothing. So eventually found a safe spot to pull over and open the bonnet to have a look. I was not overly concerned as I have an oil light/buzzer combo as an instant warning (Mr T forgot this). So, I could see the positive wire had come out of the terminal on the sender unit, this may have been knocked/loosened yesterday when the entire chassis/engine was put through the local HGV pre ITV steam facility. So I pushed the wire back in and still no gauge, I have little doubt this has touched earth and shorted.

I am still miles from home but have basic tools and a multimeter, I can confirm I have 12.2v on the positive (white wire paralleled with another white with brown tracer and the other wire is to ground which is white with black tracer. The sender resistance alters with varied RPM's, everything else on the car is working perfectly, fuses all good, I do not have a diagram and would appreciate someone posting one up for me? I have a mobile internet dongle and the signal seems OK......ish up here so should be able to get online again later?

I not stranded in any way and I will be back to civilisation in a couple of days but while up here doing nothing.........

Many TIA

regards

Dave
 
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Had a good look at the schematic and I am guessing the gauge is toast, probably as result of the 12+wire being earthed? The voltage disappears as soon as the sender is connected. I will pull the dashboard later this morning and see what I can see.

Thanks again Chris

regards

Dave
 
Update, spent awhile following the schematic and I had all the right power in all the right places but the gauge was not moving. After a lot of head scratching I noticed how easy the needle moved in one direction but not the other, my eyes are not great on anything close up but with my bestist glasses I could just see the pin on the bimetallic strip had come out of the slot in the needle base. My assumption is when the cable earthed the bimetal got so hot it pushed past the sweep of the needles limit and pulled out of the slot?

I will pop the dash back in tomorrow and refit the sender and test it and get back with the results, I took a couple of pics and will post them on my thread on MUD, I am having so much trouble even typing this post on this forum, I just know the pic will mess it up.

regards

Dave
 
Sorry for the late update, the off road competition I was attending run over time today . So the gauge problem was as expected, in a nutshell the bimetallic strip pulled at the needle so hard because of the dead short it pulled the guide pin out. Once it was all back together I then recalibrated the sender to the gauge and all is well again.

Thanks again Chris.

regards

Dave
 
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Good news.

I have wrestled with the oil sender before and never found a solution. Had the gauge in bits too as you described. Every single component and connection seemed fine and yet it simply never worked. I even replaced the dash gauge s well as the sender.
 
No worries mate you're welcome
I don't have that 80 anymore so it's academic now but I created the same problem when I whacked 12v across the gauge on the bench
I had a spare and put that in
Nah. Voodoo I gave up in the end but not before buying a OP testing kit and checking the actual pressure which was bob on
C
 
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