Originally Posted by milkfish888
Hi Jerry! Thank you very much for your help! I followed the instruction from your earlier post to check on the 125AM fuse located in the AI's rear under the seat in the center area. From the rear of the AI, I opened the access panel. I saw two fuse boxes. One is labeled as "CHASSIS BAT.". I think this is the fuse you were talking about. The other fuse box is labeled as "INVERTER FUSE". There is a cable leading from the CHASSIS BAT fuse boxe to the Battery Separator, so I think I located the right fuse. It is a 125 AMP fuse as you described. The fuse has a clear plastic window and it did not appear to be broken. I used a multimeter and selected the "Continuity". I got the beeping sound so I think the fuse is good. Any suggestions would be appreciated!
If you check the voltage with the engine off, you should read whatever the coach battery voltage is on both sides of that fuse. If you only read it on the right side, that means the fuse is blown and you should be able to visually see that the fuse is blown as well.
If you start the motor and let it run a bit, you will hear something click back there and now the voltage on the left side should read around 14V, thus showing that the alternator is charging the batteries. If the fuse is blown, the right side will read whatever the coach battery voltage is. If the fuse is not blown, the right side will be the same as the left side of the fuse and will also read around 14V at the battery terminals as well.
One thing to remember is that the alternator will not charge the rear batteries if they are at full charge, thus the voltage on both sides of the fuse will be whatever the coach batteries level is. Since my batteries were at full charge, to check if the alternator was charging, I had to turn on the furnace for a bit to run down the batteries.
If you never get the 14V reading, then either the alternator is not working or the front fuse is blown. As I mentioned earlier, I do not know which fuse in the front is the correct one. If all else fails, call Airstream and they can tell you. They were very helpful when I was troubleshooting mine.