How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Randall Your Own Question
Randall, RVIA Certification
Category: RV
Satisfied Customers: 11284
Experience:  RVDA/RVIA Master Certified Technician with many years experience.
Type Your RV Question Here...
Randall is online now
A new question is answered every 9 seconds

Relay..power from rv battery to converter not pulling in..coil

This answer was rated:

2007 Coachmen Freelander. Relay that passes power from RV battery to converter not pulling in. No 12 volt to coil. Where does the 12 volt coil power come from?
Hi: Thank you for coming to Just Answer with your question. My name is XXXXX XXXXX perhaps I can assist you with this issue.

Are you talking about the disconnect solenoid? The power goes up to the switch and comes back to the solenoid. Be sure you check the fuses on this unless it is the old style with no fuses. Is this the one by the batteries or under the hood in the Battery Control Center? Not all of these are exactly the same. If you can attach a photo to your post that would help. You may have to crop it down with your photo editing software first. R.J.
Customer: replied 6 years ago.
This is not the disconnect relay. There is a relay under the step,graphic in the battery compartment just ahead of the fusable link. I hope the picture shows that.
I don't know where the switch is that control that. I think I would contact Coachmen which is now a part of Forest River HERE and see if they have a schematic of this for you. That is highly unusual. Most coaches have a resettable shortstop breaker there. Those just tip if the amperage draw gets too high. No switch on them. What is under the "Bussman" rubber cover? These are sometimes covered by some protective rubber cover opr is this the fusable link...........kind of redundant if that is the case. I am wondering if it is tied to the ignition circuit and becomes energized when you turn the key off..........or is supposed to. Or just the reverse if this is how the coach batteries charge when the coach is running. What does it read on the feed side? Any voltage coming into it with the coach off? That would help determine what the function is. Get back to me with what you find. R.J.
Customer: replied 6 years ago.

Now I'm kinda baffled. I started the motorhome, and the relay pulled in. I measures 12+ volts @ the coil between the coil and battery negative. After I shut the engine off, the coil was still pulled in. The baffling part is, that from the battery neg. to the coil = 0 volts. But from bat POS to the coil, I now have 12 volts. I don't get it. I'm a commercial electrician, but this 12 volt stuff throws me for a loop, sometimes.

And as you know when it is intermittent it really can make you scratch your head. I think the purpose is so that the alternator can charge the chassis batteries while driving. This system isn't used now I don't think. Many have what is called a "BIRD" system which controls the charging based on the voltage measured at the battery so it doesn't overcharge. At least we know where the power comes from............and it may be some wear in the key switch is making this work sometimes and not other times. Not uncommon in older units. Get back to me if you need more on this. R.J.
Randall and other RV Specialists are ready to help you