Solenoid / converter issue? Trouble with battery disconnect

Well I’ve had my first new-to-me RV (2000 Roadtrek 200 Popular) for my first full summer and everything was working as should – frig, heater, AC, generator, etc. Then a few weeks ago I had trouble turning the aux. battery on and off but after several tries switching the rocker switch back and forth it would work. I thought maybe I had a problem with the switch and would have to replace it. However, when preparing for a trip last week I could not turn the battery on at all. When I tried I got the cha-chunk sound of the solenoid but no power. The battery power indicator light turned on briefly then faded out. I tried running the generator, running the RV and hooking to shore power hoping that switching between the different modes might flip something back and I would be able to turn the battery on again. No luck. Everything was still functional on shore power which I knew we would have access to on the trip so I didn’t worry about it.

During the 5 day trip I would periodically try the battery switch but nothing powered up. After arriving home (a 3 hour drive) I still could not switch to battery power and thought maybe it was just not taking a charge while driving. I hooked it back up to shore power to see if I could recharge the battery. After about 5 hours I went and checked on it. Good thing I did! I soon as entered I could smell what I thought was an electrical fire. There was no smoke but a very strong smell. I immediately disconnected the shore power and checked the converter which is located under the dinette seat. The wooden cover under the cushion was warm to the touch. I opened it expecting the worst. Everything looked fine but the solenoid was very hot and one of its fuses was blown. The strange thing now is the aux. battery is stuck on. I turned on an overhead light and the exhaust fan. Both worked so I know I’m getting battery power.

I should mention too that during our trip, while hooked to shore power, I tried to check the tanks levels. The indicator lights briefly lit then faded out. I checked them again after arriving home and was hooked to shore power again and still no lights. And now, though the battery power is stuck on the indicator lights still do not light.

All pretty confusing to me. Any idea what the problem could be? Battery? Control panel? Solenoid?

Thanks for any incite you can provide.

26 Replies

TrekerJack
Explorer
Oct 14, 2013
Final update... After getting the new relay in and working the control panel was still "dead". I caved and took in to a dealer. As I suspected, it was a faulty circuit board. They replaced it and everything works as should. The circuit board was $50 but of coarse I had to pay for all the diagnostics labor - ouch!! I learned a lot from this project but need to learn much more so I can avoid the dealers!

Thanks again for everybody's suggestions and input.

Hope to get some more camping in before the snow flies here in western NY.
TrekerJack
Explorer
Sep 20, 2013
Well that familiar cha-chunk of the relay is back! I put the new relay in today and sprayed the disconnect rocker switch with silicone spray and everything works as should - almost.

On my control panel is the battery disconnect switch, water pump switch and a test switch. The test switch is also a rocker switch which when held down lights the tank level and battery level indicator lights.

Now with the new relay, the battery disconnect switch works as should and so does the water pump. When I pushed the test switch the lights lit for only a nano second. Any idea why they still don't work? Bad switch? Bad circuit board?
TrekerJack
Explorer
Sep 18, 2013
I ordered a new relay. Will let you know how it goes.
Chris_Bryant
Explorer II
Sep 15, 2013
That center plunger rod should move freely-

I agree if it has been that hot, resurrection seems unlikely.
Another issue that can cause overheating is if the activation switch got stuck, applying constant power to the coil.
tenbear
Explorer
Sep 15, 2013
There is no reason a latching solenoid/relay should get warm if it is working correctly. It is probably getting warm because the contacts when they are supposed to be closed, or open, are actually a high resistance and the current going thru them is producing heat. Sounds like a bad solenoid to me.
MEXICOWANDERER
Explorer
Sep 14, 2013
SOMETHING in there has to move. To make the copper contacts touch. If the solenoid has a permanent magnet compensate for this. A contact may need to be pried away from a magnet. Scorched? No, electrical stuff does not like being burned-at-the-stake. I scrapped any and I mean ANY winding that had the color changed darker than OEM, whether it was dyed clear or solid epoxy coating. If your solenoid tried to play the part of a heater it'll will have about as much success as a heater that tries to play solenoid.
TrekerJack
Explorer
Sep 14, 2013
In the troubleshooting section of the relay service manual, under "Relay won't Disengage", its says:

"While switch is engaged, check voltage across the coil terminals (+ on the "S" terminal and ground on the "I" terminal). If 0 volts, replace panel, if + voltage, replace relay."

With the switch held in the "on" position I got neg. volts. When held in the "off" position got pos. volts. Does this make sense?

Anyway, I figured a got current flowing from battery, thru the relay to the switch and the switch is working.

I removed the relay and opened it up to inspect/clean. I smells the nasty burn smell but nothing looks damaged and everything moves freely - I think. On the inside of the large posts are large copper blocks (contacts?). Are they supposed to move at all? Should I be able to move the center post that the springs and washers sit on up or down by hand?

When I removed the relay I found that the mounting bracket had gotten hot enough to scorch the wood panel it was mounted on.
MEXICOWANDERER
Explorer
Sep 14, 2013
Chris Bryant,

Thank you for that image and information! This is something "new" to me and I am going to take a closer look at that solenoid.

-Mil Gracias
DiskDoctr
Explorer
Sep 14, 2013
Chris Bryant wrote:
I would disconnect the battery first, and I would sure try cleaning it. You basically have 2 contacts (the inside ends of the two large studs), and a large washer to clean- you can even just flip the washer if it is burned.
There is a spring inside, though not a strong one.

This seems likely. If the solenoid itself is getting warm, a burnt contact inside can make a higher resistance connection, leading to a number of problems, including heat.

Good advice, let us know how you make out.
Chris_Bryant
Explorer II
Sep 14, 2013
I would disconnect the battery first, and I would sure try cleaning it. You basically have 2 contacts (the inside ends of the two large studs), and a large washer to clean- you can even just flip the washer if it is burned.
There is a spring inside, though not a strong one.