HWH 325 Box Failure---Repaired!

[siggyd]

After parking my 05 KSDP for 3 months at the house,I could not get the jacks up,engine starts,but airbags do not fill up. The Touch Pad was dead in ACC or IGN,the box has some red LED. Called HWH ,they called back in a few hours and send me the Service Manual as a PDF file. No shorts were found on the Touch Pad red and white wire or the outgoing wire # 6800 on the Box from connector CN8.Pulled the rubber seal off the plexiglass on the box and find LED #38 lit and fuse F10 (10 Amps) blown.A new fuse did blow in an instant.This means the box is bad, confirmed by HWH.They offered to repair the box for about $100+ shipping and parts,if the fix is simple.Since I have very many years of industrial electronics troubleshooting on my back,I removed the box and put it on the bench and found TVS (trancient voltage suppression) Diode D3 shorted, located about an inch below the F10 fuse. Ordered a diode from NEWARK (4 days) for $ 0.50 + 5.65 S&H and installed the tiny thing,tested the system and all is working A OK.
This diode is there only for the protection of the box from overvoltage---so in an emergency , if the diode is shorted ,I would cut the diode D3 and replace the fuse and be on my way.
Siggy D.

[oemtech]

Outstanding.... I have not done and component level work in years. I am in the R&R mode - Remove and Replace.

[GaryKD]

Hi Siggy,

I could never do what you did. Thanks for the information on what one could do in an emergency situation.

Did you have any difficulty reinstalling the rubber grommet around the plastic cover to seal the box back up?

[siggyd]

Hi Gary,
No it was not too difficult to get the rubber grommet back on,I used just a little Vaseline.But remember ,I did this on the workbench. Getting the box out and back in was a little work,since Newmar ? installed the box in an awkward place.You can not look straight into the box,you have to kind of break your neck first.
Siggy D.

["007"]

Thanks siggyd for your post thought we were going to have another fuse caper.
Will have to remember this one who knows when it may appear again.