Oil press gauge dead - fried something

[clintnz]

Hi guys, while I was waterproofing the 1UZ the other day a redundant wire from the old 2LTE loom fell on the exhaust & subsequently fried itself, at the same time the oil pressure gauge & 4wd light stopped working. I checked the gauge sender unit with the meter & it still works ok.

I'm wondering if the gauge, & whatever the mystery wire was, both used one of those low voltage systems & I've fried something behind the dash? Any clues on what the problem might be & tips on how to get at the offending electrical doohickey will be greatly appreciated.

Cheers
Clint

 

[Welby]

Hi guys, while I was waterproofing the 1UZ the other day a redundant wire from the old 2LTE loom fell on the exhaust & subsequently fried itself, at the same time the oil pressure gauge & 4wd light stopped working. I checked the gauge sender unit with the meter & it still works ok.

I'm wondering if the gauge, & whatever the mystery wire was, both used one of those low voltage systems & I've fried something behind the dash? Any clues on what the problem might be & tips on how to get at the offending electrical doohickey will be greatly appreciated.

Cheers
Clint

I had to replace the oil pressure gauge on my 75, the gauge was $200 and I had to take the dash out to get to it. At least the 70s have everything attached with screws or nuts and bolts, and not a multitude of 1 operation plastic clips.

 

[Cruiser D]

Same thing happened on my BJ. My sender was completely rusted away and the wire was dangling. I have learned that if the wire going to the pressure sender grounds out it will pull enough current through to melt the fragile coil that moves the gauge needle behind the dash.

I am currently trying to figure out how to fit a mechanical gauge to move the stock needle. The gauge is too delicate for the abuse these trucks take....get a mechanical one.

 

[nickw]

Maybe that is why my gauge is not working.
The oil pressure gauge started doing wonky things (up and down and staying high). Then it failed about 3 hours later.

I checked my sender and it seemed good, but perhaps its the problem.
Interesting though, t he other day is started to move up and down and then stopped. Any ideas?

 

[roscoFJ73]

Maybe that is why my gauge is not working.
The oil pressure gauge started doing wonky things (up and down and staying high). Then it failed about 3 hours later.

I checked my sender and it seemed good, but perhaps its the problem.
Interesting though, t he other day is started to move up and down and then stopped. Any ideas?

These gauges are always dying. Aussie wreckers charge 2-3x as much for an oil gauge as other gauges because they are always in short supply.

They often do the up and down thing in their death throes RIP

 

[Gold Boy]

i'm curious, where is the oil gauge 24v ground?

 

[nickw]

i'm curious, where is the oil gauge 24v ground?

The block?

 

[Cruiser D]

its my understanding that it grounds through the sender, as the sender resistance changes w pressure, the current changes and the needle moves....but when the lead grounds out and doesn't get any resistance, too much current draws through the coil behind the dash and it melts itself.