Oil pressure issues!

[Recovry4x4]

I've had this problem with the multifuel engine that I installed in the M108. I know it has oil pressure because when we burped it while it was still in the other truck, the oil gushed out where the can was missing. I got the dash out of the donor truck and it had a 120psi gauge in it. When I got the truck running, the gauge didn't read. Figuring that the sending unit might be wrong, I installed a 60 psi gauge but still had nothing. Luckily I had and extra 120psi gauge too. I swapped that and still nothing. After a bit of searching, I found another 120 psi sending unit (years of collecting). After installing that I hooked everything up, still nothing. Last night I spoke with Cranetruck and he said the gauges need to be grounded. I had been testing gauges before installing them so there was no ground. Today after starting the truck I touched one of the mounting bolts of the gauge on one of the dash bolts and it worked! At least I know why they put the 120 psi stuff, runs a little over 60 psi at idle. I'm pretty happy considering the no oil pressure issue that brought about this engine change. Bottom line, make sure your dash panel and gauges are grounded.

 

[BFR]

do the gauges ground to the panel & the panel to the dash? Is there a grounding strap invloved anywhere?

 

[cranetruck]

Glad you discovered the problem, Kenny.
My "Grounding article" didn't make the deadline or it would have been in the current issue of the MVM, hopefully next issue.
Here is one of the illustrations (from PS magazine).
http://www.steelsoldiers.com/module...ile=index&name=gallery&include=view_photo.php

 

[Recovry4x4]

As shown, the gauge grounds through the mount hook, then through the screws to the dash of the truck. I'm just thankful that my I've confirmed adequate oil pressure.

 

[ida34]

On all my work trucks I like to put in a mechanical gauge. Nothing much can go wrong with them and they do not lie as much as electrical gauges. I also keep one loose to attach for diagnosis of low oil pressure on an electrical gauge. Oddly enough I will be doing this tommarow with my F-350 when I do a tune on it. They only cost about $10 the last time I checked and I just put it in the tool box until needed. I would put one in the deuce but I want to keep it stock looking. I am only going to add a pyrometer and boost gauge. When I do hook up my diagnostic gauge I always do it with a t fitting so I can compare the readings between the electrical and mechanical gauge. Most modern cars with gauges really are not to accurate and are really just glorified idiot lights.

 

[rizzo]

will the military gages in my M810 work on 12 volt?

 

[Recovry4x4]

Hmm, that I don't know. Bjorn!

 

[cranetruck]

If you look at the gauge (when out of the dash), you will see that it's marked "24vdc".
Testing it on the bench I noticed a lower reading when used with 12 volts. Guess you could get used to it, but wouldn't be accurate.

 

[rdixiemiller]

I had the dash out of my truck one day while I was tinkering. I noticed none of the gauges worked. I touched the panel to the dash, sparks! Gauges worked!
I have since installed a ground wire with a Packard connector.