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Robert, RV Mechanic
Category: RV
Satisfied Customers: 13359
Experience:  18 yrs. RV experience including Cummins North West, Country Coach, Monaco Coach - vendor certified.
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I have a 2003 40' Allegro Bus. I unhooked from shore power

Customer Question

I have a 2003 40' Allegro Bus. I unhooked from shore power and then tried to put my slides in. The motors ran very slow and would only move the slides a few inches and then stop. It acted like I had very weak coach batteries, so I started the engine and the slides retracted with full power to the motors. Shortly after that, I had no 12v power to anything in the coach. Everything 12v works when I am plugged into shore power or if the engine is running.
I checked voltage on the 4 6v coach batteries and they show 6.8 volts. I also turned the 12v disconnect switch on and off while plugged in and it seems to work properly since the lights go on and off when using that switch. It is in the on position now.
Is there a main circuit breaker or fuse for the 12v side? I have absolutely no 12v power now, but it baffles me that I had a very slight amount of 12v power when I originally tried to put the slides in, but now I have no 12v power whatsoever.
Thanks for any help you can give me on this....Don
Submitted: 1 year ago.
Category: RV
Expert:  Robert replied 1 year ago.

Hi my name is Robert....

What I would do is go to the batteries and follow the cables to the solenoid, when you hit the switch inside it should trigger a solenoid valve. Many times you can hear the solenoid click when you hit the switch. Check for voltage on each side of the solenoid on the LARGE posts, if you have power on one side and not the other get an insulated wire and jump the solenoid and see if power comes on. As you are following the cable make sure there is not a breaker between the battery and solenoid, if you have voltage on each side of the solenoid make sure you do not have a breaker tripped from the solenoid to the fuse box outside. Below is a picture of what the breaker might look like, most have a small tab that pops out when they trip. As a general rule they like to put the breaker 18" from the battery and could be on the frame or inside a battery control box. Check your cables make sure they are clean and tight as well... Hope this helps some.... Robert

Expert:  Randall replied 1 year ago.

Hi, Don........have you had the batteries load tested recently? Surface voltage won't really tell you the acutal condition of them. I would do this and also perhaps jump across the main disconnect as I have seen those give a decent reading, but fail to allow adequate amperage flow across in order to move slides. Places that sell batteries can usually load test them for you. Hope that proves helpful here. Please get back to me if you need more help with the testing.

Expert:  Randall replied 1 year ago.

Sorry for the post tablet didn't show any response yet.

Expert:  Robert replied 1 year ago.

Please let me know if you need more help...... I would go to the solenoid and see what the voltage is, it should be around 12 volts, if the voltage is low trace the cable back to the batteries make sure the cables are clean and tight. IF no breaker have them load tested to make sure they are not the issue, make sure you mark the cables if you remove them.....


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