electrical switching issues

[Malder]

I got a new motorhome (1990 Tioga) and am working on sorting out a few issues before our first outing.

All the electrical components work when on shore power. When I uplug and hit the switch to turn on the coach battery I get nothing but a click. Once the lights worked briefly and then quit.



I traced the wires from the switch back to the source of the sound. I searched around and as best I can tell this relay isolates the house/chassis batteries from discharging one another, but allows them both to be charged?




When I jump across the relay everything works as I would expect.

Now for the questions -

Is this relay something that can be repaired or does it just need to be replaced?

Is this system a good way to go? Is this a good time to upgrade to something more reliable, easier or better?

Thanks for the help.

[wa8yxm]

It might not be the relay.. In my coach I got a click when I pressed "STORE" (off) and nothing when I pressed USE (on) bad switch.

[Vulcan_Rider]

darsben wrote:
For those who are looking for conductive grease.

http://www.ebay.com/sch/i.html?_nkw=Conductive+Grease

Good reference.

Please note two things about that:

The first 20 or so hits are indeed for electrically conductive grease but note the applications that they are intended for; NONE mention anything about relay contacts.

The next batch of hits are for THERMAL conductive grease which is for heatsink applications and usually is NOT electrically conductive.

[darsben]

For those who are looking for conductive grease.

http://www.ebay.com/sch/i.html?_nkw=Conductive+Grease

[westend]

MEXICOWANDERER wrote:
You couldn't pay me to use a regular can type solenoid - they are short lived unreliable y-o-n-k-e

Yes, I see that some of the good tower type solenoid relays like Cole-Hersee are rated to 300 amps continuous. The bog standard two pole with a coil aren't rated near that high. No surprise as that same technology was in use on the fender well of a '51 Ford.

[Malder]

darsben wrote:
Take it off. Take it apart by undoing the four Philips head screws. There is a big washer inside that gets arced over preventing electric flow. Burnish the washer and contacts then use some conductive grease. Vaseline in a pinch. Problem solved. I have done this twice

Thanks for the tip. Took it apart and the washer was all gummed up. Gave it a good polish and it works good as new. Saved me $60! Thanks!

[MEXICOWANDERER]

You couldn't pay me to use a regular can type solenoid - they are short lived unreliable y-o-n-k-e

[MEXICOWANDERER]

OFFICIAL SALESMAN SWITCH REPAIR TOOL


http://upload.wikimedia.org/wikipedia/commons/2/20/MkII_07.JPG

[tenbear]

It seems to me that things are operating as designed. As smkettner said, by turning off the coach battery switch when on shore power, the coach battery is not being charged. When you bypass the battery isolator solenoid, you are running the coach off the chassis battery. The solenoid is probably designed to be closed when the ignition is on, at least that's how mine works.

Leave the coach battery switch on when on shore power and things will work fine, assuming the coach battery hasn't been killed.

[Vulcan_Rider]

darsben wrote:

Did not say dielectric grease I stated conductive grease but a light coating of Vaseline although not a good conductor will allow electric current to pass.

I've been in the electronics industry for 50 years.
I am not saying this just to start an argument.

Just exactly what type of "conductive" grease did you use and where did you get it ? In my experience it is not readily available to the average consumer and is expensive. Improper use will short stuff out.

Then.....things like vaseline and WD 40 are NEVER good things to put on electrical contacts, first because they are really insulators and secondly as they attract and accumulate dust and debris they become even more insulative. And while that is happening the contacts tend to arc and burn more than normal.

If you do much of this kind of work, it would be a good investment to get a can of contact cleaner spray.......or just plain rubbing alcohol.

[darsben]

Vulcan Rider wrote:

darsben wrote:
then use some conductive grease. Vaseline in a pinch. Problem solved. I have done this twice

Di-electric grease is NOT conductive and neither is Vaseline and neither should be put directly on contact surfaces.

Did not say dielectric grease I stated conductive grease but a light coating of Vaseline although not a good conductor will allow electric current to pass. Specially with good metal to metal contact. And that switch has good metal to metal contact and will suffice IN A PINCH

[Chris_Bryant]

Never heard of Essex type- are they latching relays?

[MEXICOWANDERER]

I use Essex tower type solenoids and in twenty years I have disassembled and cleaned the contact disc and studs - exactly NUNCE. Salesmen switch circuits seem to exist, solely to fail one way or 100 others and drive the owner nuts.

[Vulcan_Rider]

darsben wrote:
then use some conductive grease. Vaseline in a pinch. Problem solved. I have done this twice

Di-electric grease is NOT conductive and neither is Vaseline and neither should be put directly on contact surfaces.

[Chris_Bryant]

Adding to the just repair it camp- a cutaway of what that latching relay is like inside- note the washer darsben mentioned- usually they have grease in them which has solidified, keeping it from making contact. Clean, polish and regrease and you're good to go.


When you press the switch to connect, the polarity of the coil pulls the rod magnet to hold the plunger down- when you push disconnect, the coil polarity is reversed, pushing the rod out of the way.