12 Volt Accessories Issue

[bcpoleclimber]

We have a 1999 Thor and recently the power step stopped working. I soon realized my problem wasn't just the step but several of the accessory switches have stopped working, including the power mirrors, the emergency start switch, as well as the fans over the driver & passenger seats. There is a mirror heat switch located in this bank of switches as well which I cannot test for operation but can say the indicator light on the switch does illuminate. I have noted that in the Battery Control Center manual that the fuses for all of these functions are close together but the fuses I've checked look OK. Any help troubleshooting this is much appreciated. Thanks!

[javelin]

I own a 2013 ACE 30.1 and I am sure that its BCC and your 1999 BCC are probably quite different.....but I believe many RVs use the chassis battery to operate the steps and some other accessories as well. Since you say the BCC fuses for the affected devices are good then perhaps the common 12v feed to (or through) the BCC to those fuses is open? My coach must have the chassis battery latching relay (located inside the BCC) “on” to power the fuses for my steps and some other accessories. It is not uncommon to have a failed latching relay (assuming your BCC has them); or low chassis battery voltage or some other open cct in that 12v BCC fuses feed path.



Regarding the Aux start switch, I think you should hear the BCC interconnect relay operate when the Aux switch is operated which connects the chassis and house batteries together.......assuming the cct board in the BCC is powered and functioning correctly. Hope that helps a bit.

[bcpoleclimber]

Thanks for your reply! I think you are on to something as there is also a button to test the isolator relay in my BCC and this is not working properly either (doesn't click when pushed). I am going to do some testing with my voltmeter on the weekend and will post my findings.