oil gauge
 

my oil gauge for my 56 merc isn't working it measures 41 ohms across terminals unhooked, from the sending it shows ground, changed sending unit it shows grd, with external gauge it works fine, the dash gauge when switch is turned it goes to max start engine it goes slowly to 0. any ideas???

Re: oil gauge
 

It seem like there were different systems on different models in 56. Some had gauges and some had the warning lights. The senders aren't compatible between the two. The gauge can be tested with variable voltage power supply applied but I don't know what the specs are without the book. If I recall correctly, the sender would have a capacitor attached on those but my memory isn't what it used to be.

Re: oil gauge
 

If I read you correctly, you have a separate aftermarket electrical gauge and are using the sender for the aftermarket gauge with the the factory gauge. If so, the aftermarket sender probably isn't compatible with your factory gauge.

Re: oil gauge
 

YOU'RE GOOD! ;)

I read completely over the aftermarket sender.

Re: oil gauge
 

Found out the sending unit for a merc is different than ford, got sending unit from Classic Mercury

Re: oil gauge
 

THANX! for getting back and sharing that info. I did not know that.

Do you have a MERC PN?

Re: oil gauge
 

when I get the part I will post