Short in dash switches

[jbramhall]

I’ve got an intermittent short in the 2 rows of switches. When my dash fan is on, it runs for a few minutes, then the fan stops operating, the radio shuts off, and the wiper, windshield fan, and both sun shade switches have no effect.

Often, turning the engine off then restarting fixes the condition, but not all the time. My sense is that these switches operate relays and the power to the relays must be out.

Any ideas?

[Oscarvan]

No relays that I am aware of. What I suspect is that they share a connector somewhere in the loom that may be getting loose. Open up and follow the wires from the back of the switches..... see what you find.

Another option is that they share a common power source. You can find the schematics on DTNA. They may provide some insight.

Last but not least, the ol' adage "Most electrical problems are bad ground" The panel is plastic, so they all have wires to ground. Follow them and see what you find.

[jbramhall]

Thanks for the tip. I think I have a few hours with my head in that dash panel in my near future!

[babock]

If you had a short, you would have blown a fuse. You have some sort of intermittent connection.

[jbramhall]

Originally Posted by babock

If you had a short, you would have blown a fuse. You have some sort of intermittent connection.

Do you think I should still look for an incomplete ground issue? Not a "short" per se, but it seems to be the most reasonable first place to look given the variety of inoperable switches.

[babock]

Originally Posted by jbramhall

Do you think I should still look for an incomplete ground issue? Not a "short" per se, but it seems to be the most reasonable first place to look given the variety of inoperable switches.

Absolutely! Would be one of the first things I would look for.

Best thing to do is to do what a previous person mentioned...find a schematic.

Another thing I do in cases like this is, if possible, put my hand behind the area and start moving the wires around while watching everything that is powered. See if you can duplicate the failure with your hands.

[jbramhall]

Originally Posted by babock

Absolutely! Would be one of the first things I would look for.



Best thing to do is to do what a previous person mentioned...find a schematic.



Another thing I do in cases like this is, if possible, put my hand behind the area and start moving the wires around while watching everything that is powered. See if you can duplicate the failure with your hands.

Yeah, I jiggled some things on a roadside stop with no luck. Because the only critical system affected is the wipers, I drove home the rest of the way in the sunshine and am getting ready to go deep in there today.

I signed up for a Daimler account today. Not sure how long that takes to complete.

[FORKLIFMAN]

More than likely,You do not have a short, It is more like an open circuit. (lose connection s ) . It could be positive or negative source? When is the last time you cleaned your battery cable connections for you engine battery ? I mean remove the cables, clean the posts, and the cables internally . I have seen a lose negative battery cable, cause all kinds of "crazy" problems!!And dirty cables as well.

All the things that are affected are more likely to be fused separate from each other. So more than likely it would be a ground issue. I have seen dash wiring, having all the ground wires, connected together and fastened together to something metal under the dash, with a bolt or screw, ,aking them all have a common ground connection. Or even spade connections for all of the wires plugged in. So this may be a possibility? As some one suggested just follow the wires, and you may see something obvious or suspicious? Good luck!

Be careful!! Use to do auto electrical repair work. Last week while under my dash working on side mirror wires to right mirror. Still trying to do things, that shouldn't be doing, got stuck between the engine cover and the passenger seat. After a few minutes of laughing, finally was able get my self out of the spot. Need to keep reminding self. Your NOT 18,..... OLD MAN!

Hope this helps a little?

Cheers David

[jbramhall]

So. Thanks to all for the guidance. After spending an hour jiggling wires behind the dash with no success, I took the bus to my local RV repair shop. After an hour, they found the problem. It was a failed solenoid found in the center of my electrical bay located under the driver seat. Here’s a picture of the failed $36 part.

[FORKLIFMAN]

YAY ! Glad it got fixed! Appreciate the update as well. Years ago, way back, that solenoid was used more for the starter, to boost the amount of power, on Ford predominantly. Over the years , they have been used in "lots" of different applications. In fact it was common practice , us old hippies, Would use them to help boost power to the starter on VWs 6 volt and 12 volts. Both the Bug and Bus,,, mmm even some Karman Ghias

Cheers David

[jbramhall]

Originally Posted by FORKLIFMAN

YAY ! Glad it got fixed! Appreciate the update as well. Years ago, way back, that solenoid was used more for the starter, to boost the amount of power, on Ford predominantly. Over the years , they have been used in "lots" of different applications. In fact it was common practice , us old hippies, Would use them to help boost power to the starter on VWs 6 volt and 12 volts. Both the Bug and Bus,,, mmm even some Karman Ghias



Cheers David

I’d be lying if I said I knew what the thing does. I get relays and, of course, ground connections and switches, but I got no idea what that solenoid does. The tech said it also would also have interfered with chassis battery charging. It was 100° out, and I ran my genset for coach AC while driving on my last trip, and that must have kept my chassis battery charged. I’m lucky, but not knowledgeable on this topic.

[Oscarvan]

A solenoid IS a relay. (Says it right on there).