helperzack
Florida - Tennessee
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I continue to have an intermittent problem with my motor home house 12v power when disconnected from electric service.
My 12v cut off switch does nothing. Sometimes all of the 12v items work just fine, other times nothing will work unless I start the generator or plug up to outside power. I cannot figure out if there is anything that contributes to this problem.
I am thinking it might be the Disconnect Relay Solenoid. I have located the one connected to the house batteries. If it is the problem I am thinking there would be some specs on it that I would have to match in a new one, correct?
Do you know of a way that I can test it with a volt/ohm meter to tell if this is the problem? Or do you think my guess is correct?
Help and suggestions appreciated.
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Jagtech
Sunny Southern Alberta, Canada
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Intermittent electrical issues are the most difficult and frustrating to diagnose. Have you checked, using a DC voltmeter, if there's 12 volts coming from the disconnect relay? Of course, you've already made certain the battery terminals are clean and tight!
Good Luck!
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CA Traveler
The Western States
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Check the control terminals with a voltmenter. This should be a latching solenoid in which case the polarity will reverse for activating/deactivating. I've had 3 of the unreliable Intellitec ones go belly up so another approach is to just replace the solenoid. Look at it this way - if it's not bad it soon will be and you have a spare.
Since using the converter solves the problem perhaps you have a voltage/battery issue? Next time it fails measure the battery/voltage on the battery. Also have the batteries load tested.
If you don't really need the function you could just bypass the solenoid.
My current rig has 3 unreliable Intellitec solenoids: The bypass one has already failed and I can't wait for the charging and grid heater ones to go bye bye. I had 4 failures on the last rig. There I needed to say that.
* This post was
edited 04/26/12 08:20am by CA Traveler *
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Bob
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MNtundraRet
Bloomington, MN
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helperzack wrote:I continue to have an intermittent problem with my motor home house 12v power when disconnected from electric service.
My 12v cut off switch does nothing. Sometimes all of the 12v items work just fine, other times nothing will work unless I start the generator or plug up to outside power. I cannot figure out if there is anything that contributes to this problem.
I am thinking it might be the Disconnect Relay Solenoid. I have located the one connected to the house batteries. If it is the problem I am thinking there would be some specs on it that I would have to match in a new one, correct?
Do you know of a way that I can test it with a volt/ohm meter to tell if this is the problem? Or do you think my guess is correct?
Help and suggestions appreciated.
-------
While off shore-power, no generator, use you multimeter and read the voltage at the house battery-terminals. What is the voltage?
Anything less than 12.6 volts suggests maybe a battery problem.
Now plug into shorepower. Use battery-disconnect to connect the battery-bank. Check the voltage at the battery-terminals again.
If you have a converter/charger with multistage charging you should be 14.4 volts for "bulk mode" charging, 13.6 volts for "general mode" charging, or 13.2 volts meaning the converter is working but charger may a failed. If you still see your original reading of 12.6 volts or less the converter/charger has failed. Look for a tripped breaker or blown fuse.
If they are okay time to replace converter/charger and maybe the battery(s). PLease note that if your house-battery(s) is less than 11 volts the disconnect solenoid will not function.
Also; when your start the engine the alternator solenoid circuit bypasses battery disconnect and you should see 14.4 to 15 volts at the battery-terminals. When on shore-power the converter/charger will power the 12 volt circuit but cannot charge the house-battery(s) if the solenoid is stuck in the "off (disconnected)" position.
Mark & Jan "Old age & treachery win over youth & enthusiasm"
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nevadanick
Elko, Nevada
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I had that problem on my tt and it was the thermal break/Fuse on the hot coming from the batteries
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stinksweet
Tennessee
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We had to change the solenoid out today. To check, put your black lead on a ground and the red lead to the post on one side of the solenoid and check your volt reading. Then move the red lead to the post on the other side of the solenoid and check the volt reading. You should get a volt reading on each side. We had a reading of 13.2 on one side and 0 on the other. This has fixed our problem so far. We are keeping our fingers crossed. 
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vance
USA
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If you see any drop in voltage accross the solenoid, consider replaceing it.
vance
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MNtundraRet
Bloomington, MN
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It is hard to tell what you mean by intermittant power. If you mean working one minute, droping out, and returning. That can be a poor connection at battery, solenoids, grounds, etc. Try to check each for tightness and clean connection.
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helperzack
Florida - Tennessee
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In my case, we head out and no house power. I stop and fuel up and get back in and it works just fine. Works for a day while on the road then all of a sudden it's out. Then maybe a day or two later it's working again.
Some good tips above that I will be checking out this weekend. THANKS EVERYONE!
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CA Traveler
The Western States
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helperzack wrote:In my case, we head out and no house power. Pull over, stop, leave the engine running and get out with your voltmeter and locate the problem! Could be a solenoid, loose wire, intermittent fuse/CB etc. But with no house power it will be one of the big power items.
Truthfully it could be a month of Sundays or more before a service shop might find the problem and all at your $$$. If you don't know how to do the above then get someone to walk you through the process.
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