Charge Bridge Solenoid Blown Fuse

[jrb]

I have a 2020 Newmar New Aire 3541. On a recent trip about 4 hours after stopping and plugging in shore power I noticed the chassis batteries were low on Silverleaf. Silverleaf also showed that the batteries were bridged, but the voltages on house batteries and chassis batteries were different (13+ on house and only 10.7vdc on chassis). I suspect my chassis batteries are bad, but I have not had them load tested yet. My understanding through discussions with Newmar and the schematics I've received is that when bridged they batteries are directly connected together via the Charge Bridge Solenoid so they should read the same.

It was late so the next morning I called Newmar and talked to Erica. I talked to her in 2023 when I had a similar issue and she was very helpful then so thankful to get her this time.

I found fuse F10 blown on the printed circuit board in one of the basement bays on the driver side. I replaced the fuse, heard a click, checked the voltages and they matched. I'm not suggesting the chassis batteries are good, but just that the Charge Bridge Solenoid "ACTUALLY" engaged to bridge the house and chassis batteries together. This is the same problem I had in 2023 when I talked to Erica.

My question is whether anyone has had this same experience? If so, any thoughts on why the fuse would blow twice even though some time between occurrences? Or, anything else that may be helpful? As an engineer, I appreciate the in-depth discussion on how these systems work. I have not investigated who the "owner" is of this printed circuit board - Newmar, Silverleaf, or Xantrex. I'm just guessing that it would take some digging to find out any details on the F10 fuse blowing problem. I believe it is just a control circuit to operate the Charge Bridge Solenoid, so odd that it would blow a fuse - but the designers did put one it, so...

Any help would be appreciated!

 

[Kevin D Pem]

Fuses are there to protect wires.

Happened twice? Look for a wire that passes through some tin where it might short out while the coach is in motion.(Not protected with a bushing)

I will not explore any other possibilities.

 

[jrb]

Thanks for the reply. Fuses are to protect all electrical components. As far as a short somewhere, I understand. If you have not looked at the wiring in a Newmar RV (mine anyway) it is atrocious! Nearly impossible to trace a given wire from beginning to end. This is a huge complaint I have about Newmar in how they just stack last-in wiring on top of any previous wiring without any type of organization, bundling or labeling.

Thanks again and would still appreciate any comments.

 

[Kevin D Pem]

When rats nests are common, run a new wire.