1999 Diplomat DP dash ground.

[Jocat54]

Hi all, I need to find the main ground for the dash, can anyone give me an idea where to start? I'm pretty sure I have a ground problem--my temp gauge starts to climb when I turn the windshield wipers and/or the headlights on. As soon as they are turned off the temp returns to normal.

Thanks,

John

[jimkate]

Mine is a little older, so may not be exactly the same, but I'll throw in my two cents worth, for what it's worth, because I dealt with much the same problem last year. I'll tell you what I did.

I removed all the screws holding the dash cover and pulled it back so I could get into the dash. Up forward, up against the firewall was a buss with a whole bunch of white wires. I loosened all the connections, sprayed them all down liberally with electrical contact cleaner, and tightened them all down as tight as I could. The buss had a large wire fastened to the frame with one screw. I loosened that screw, added another wire to it going to another ground screw that I installed, then sprayed that down with cleaner and tightened the screw.

Then I opened the front outside generator door and looked up on the firewall. There I found another buss with a bunch of white wires. I did the same thing there.

Then I went into the outside electrical box (left front ahead of the drivers tire). There I sprayed all connections with cleaner and tightened all connections. I removed all fuses, cleaned them and reinstalled.

That solved all my problems.

Hope this helps.

[pipedream2]

John
I answered this exact question on the MCAO board

[mahon1993]

I had a similar problem on my 2000 Diplomat. The speedometer would "wave" at me and the dash lights would dim. I ran a 12ga wire from the ground terminal on the back of the speedometer thru the fire wall and attached it to a good chassis ground. Solved all kinds of dash problems.
Greg

[pipedream2]

Hey John

Thanks for the no- reply......my last word on the subject

[Jocat54]

Quote:

Originally Posted by pipedream2 Hey John Thanks for the no- reply......my last word on the subject

?????? Deleted response.
John

[Jocat54]

Thanks to ALL for their replies--sorry I haven't had the time to look yet, maybe after the 1st.
Evidently not fast enough for some.

John

[Snowman 1]

We had the exact same issue you have on our coach. During a visit to Coburg last year they fixed the problem by going to a heavier gauge ground wire. Back when Monaco let you stay in your coach in the service bays, I was able to watched the tech perform the repair. He unscrewed the dash, layed it forward and replaced the ground wire which was right in front. Sorry I can't describe it better. Perhaps you could lay your dash out, take a digital picture and email Monaco tech support. They could probably then point it out for you.

This was one of the most vexing problems we have had in our HR, had every repair shop in the area scratching thier heads. Never could figure out why the coach ran hot at night until we put two and two together. Ours would actually trigger a low coolant light to come as well. Good luck, it is a simple fix once you figure out which is the ground wire. Monaco fixed this in about ten minutes.

[Robert T]

I am not certain that you have a ground problem. If indeed there is an bad ground there would be problems with other guages on the dash. But a quick way to test the ground is run a separate ground wire from the dash.

The ground from Monaco most likely will see a post on the back side of the instrument cluster using a quarter inch or so nut with a single approx 12 gauge wire going to a ground source.

I have had issues with low fuel light coming on when there was low air in the bags, went off when air preasure return above 90 lbs. Cause was a bad resistor in the back of the cluster.

Check for corrosion on grounds. Your thoughts of a poor ground does have merit as the temp gauge during normal operation , as the sensors obtains heat, causes less resistances for ground and allows more voltage to the gauge.

But if you have a bad ground you would not get a noraml reading when light or wipers are on

[Rex]

John here is a picture of the ground on my 01 Diplomat. It is on the firewall just to the right of the accelerator and between it and the side of the center drawer cabinet.

[Jocat54]

Quote:

Originally Posted by Rex John here is a picture of the ground on my 01 Diplomat. It is on the firewall just to the right of the accelerator and between it and the side of the center drawer cabinet.

Rex, Thanks for the picture, it should prove very useful.

John