Skip to main content

Replies sorted oldest to newest

 Do you have a problem with the oil pressure gauge AND the water temperature gauge? 

 If that is the case I would closely check the grounding wire that serves the gauges. It is a daisy chain ground circuit that can benefit from having the end of the factory wiring also attached to chassis ground  

 Of course you would also check the visible wiring on the engine serving both of the sending units 

 Have you done any recent work on your car that might have disturbed any wiring connectors ?

Larry

https://pantera.infopop.cc/top...-the-kitchen-counter

@jfb05177 posted:

I decided to test my gauges to see if they even worked.  I really wanted to make a test stand and harness, BUT I just used a handful of test leads from my days of “keeping the lights on”.  For the senders, I had a 1Kohm multi-turn rheostat that I used to do similar for verifying the controls of 2gigawatt thermal nuclear reactors.  The battery was borrowed from my trailer “break away brakes”.

My original gauges responded and the sender resistor values recorded.  I discovered a spare fuel gauge I picked up off eBay was bad.   Even though it was from a “reputable” vendor, it has been a couple years so I guess I just learned a lesson and maybe will take it apart to see what’s inside

A tidbit I learned was that even though SOBill’s drawings imply a case ground not used, it is indeed needed.  Actually the bad gauge does not have the internal connection to case ground and thus only responds ½ to full scale with excessive sender range.

The sequence of steps was to;

Connect battery

Adjust rheostat to align needle to mark

Disconnect rheostat from gauge

Measure rheostat ohms and record

Repeat for the 5 points per guage

test gauges guage 001s guage 002s guage 003s guage 004

 

Last edited by jfb05177

My original temperature gauge will get to the red zone within 30 seconds of starting the car and then will drop down to near zero a moment later and then spring back to the red zone.  I had an additional more modern and accurate temperature gauge installed that in normal driving almost never passes 160*F.  In traffic and in warm weather, it might get to 180-190* and yet I still get unnerved when I see my old gauge head to the red.

Add Reply

Post
×
×
×
×
Link copied to your clipboard.
×