I've had this 1987 Komfort motorhome for a little over a year now we started having a problem with the chassis battery draining down to nothing and not being charged off the shore line, so I went to use the auxiliary start today and it failed to work. I checked the fuse under the hood it was blown so I replaced it then I pulled out a multimeter and I checked the solenoid both sides, the side with the house batteries read 13.7, the side with the chassis battery obviously read zero because I've been having a problem with it so I hooked a booster charger to my chassis battery and then tested the other side of the solenoid and it read about 7.5 at the time which isn't bad considering the battery was completely dead and I just had the booster charge on it. At the front of the cab I have a little 12 volt light that I had on while I was looking at my Dash and when I push my auxiliary start just that light dims really bad the rest of them stay fine. Any suggestions as to what's wrong with my auxiliary start for starters?