Community Forums

echo3 · 03-29-2012, 07:24 PM

I have had two occasions over winter where the chassis batteries got low enough that they would not start engine. In both cases, the battery boost switch did not connect the house & chassis batteries to start and I was able to just jump from the house to chassis and get started. The MH is now in shop and the tech says he hears the selenoid click and can't really check unless chass batts are down. He think selenoid is OK. Earlier, I had taken the salemans switch selenoid off and hardwired that and he is questioning whether or not the salesman seleniod needs to be in place for the battery boost to work (the is a Winebego dealer and not familiar with Monaco). Can anyone answer his question on the need for both? Also, is there a way to check the batt boost without a low
battery?
David White
'05 Windsor PDQ

DennisZ · 03-29-2012, 10:53 PM

David
That solenoid does not need to be in to make the boost work,the most likely cause if you can hear the relay clicking is it is the old copper contact style and the contacts are shot. You may need to replace the relay, it also controls the charge circuit between the house and chassis batteries if you have a BIRD relay driver installed.

Dennis

wizzo442 · 03-30-2012, 06:35 AM

Echo3: Another option is to take the old solenoid apart and clean the copper contacts. (That's what I did.) Before I put it back together, I put a smear of anti-ox compound on the contacts (the stuff you use in breaker panels when using aluminum wire). My solenoid works just fine now. The contacts in mine were green with oxidation when I took it apart.

clyon51 · 03-30-2012, 08:15 AM

Generally speaking, most mfg use the boost solenoid to also connect the alternator/chassis batt to the coach batts while driving.

You could start the engine, then check voltage at the coach batt. If no increase, that solenoid is not working/passing current.

distaff · 03-30-2012, 04:27 PM

You posted this in the Class A section as well. Generally it is best to only post the same topic once.

echo3 · 03-31-2012, 09:02 AM

Thank for advise... just not sure what groups looked at these. I appreciate comments/advise to posts as well. David White

distaff · 03-31-2012, 10:35 AM

Lots of strong technical advice in both the Class C and Monaco groups. If it is a generic Class C question, the Class C group will get a broader response. For things that are really Monaco specific you will get a better thread going on this group.

Many of us monitor both, but for example, few of us monitor the National or Newmar groups.

distaff · 09-04-2012, 12:16 PM

David (Echo3) - I wound up having the same issue. After extensive examination of the wiring diagrams and the 12v panel in the engine area of my Beaver, I found that a $6 relay had failed. I have a BIRD unit that will close the main circuit between the coach and chassis batteries when one has more than 13.5v for cross charging, and a boost switch on the dash for extra current when starting.

Neither was working, which is why I had low voltage on my chassis batteries after being parked on shore power, and I needed a jump to start the beast.

The boost switch and the BIRD unit are both wired through a Cole Hersee RC-400112-NN relay. A $6 part stopped a $300k motor home.

Don't know if you solved your problem, but I found it amusing that I walked into the same issue.