Chassis Battery Isolater Fuse

[Dave&Kacy]

After noticing that the chasis baterieskept draining and would not charge when on shore power, I found the isolater fuse (20 amp) was blown. I did not have a 20 amp fuse handy, so I rtied a 30 amp(I know, and I didn't leave it in except to run to the auto store anf get some 20s) When I returned the 30 amp was blown.

Isn't the only thing on the isolater the batteries? Why would practically new batteries draw more than 20 amps unless there was a short in one or more of the cells? Could low water cause this overload?

[Dave&Kacy]

After noticing that the chasis baterieskept draining and would not charge when on shore power, I found the isolater fuse (20 amp) was blown. I did not have a 20 amp fuse handy, so I rtied a 30 amp(I know, and I didn't leave it in except to run to the auto store anf get some 20s) When I returned the 30 amp was blown.

Isn't the only thing on the isolater the batteries? Why would practically new batteries draw more than 20 amps unless there was a short in one or more of the cells? Could low water cause this overload?

[dgerstel]

Dave,

Do you have the Echo-Charger and did you find what was keeping the chassis batteries from charging? (previous post) If you have the Echo-Charger, it only allows a set amount of amps to go to the chassis batteries. Did you check to see if it is wired correctly? I would check for other problems, but it sounds like you have Problems with the Echo-charger.

[Dave&Kacy]

Dale,

I have a Heart Interface Digital Echo Charger 1224 volt reated at 15amps. The Echo charger says that the red/stripe goes to the chassis battery, which it does. However, the Battery Compartment Layout drawing shows the red/stripe going to the house batteries.

I think that I am confused as to what the Echo Charger actually does. It appears to be a sensor that switches charging between the house and/or chassis batteries via the battery isolator. Both legs of the Echo Charger are fused with a 20 amp fuse, so why would it make a difference as to which battery set that either leg goes? Additionally, if I were to switch legs, wouldn't the 20amp fuse on the other leg continue to blow?

[dgerstel]

Dave,

I would follow the instructions from the Echo-charger, not WRV, as long as the wires are not spliced somewhere.

The Echo-charger senses when there is enough voltage at the house batteries to show that they are charging. It then connects the chassis batteries to the house batteries through it, with a limit on the amount of current flowing through it. It does not work with the battery Isolator, it is only connected to it's battery connections. The Isolator, is to split the charging current from the alternator to each of the battery banks, through 2 or more heavy duty diodes mounted to the finned heat sink.

I would switch legs to match the Echo-charger instruction and see if that cures your problem, there were many owners that said that their Echo-charger was wired backwards. If it still blows the fuse, it sure sounds like the Echo-charger is the problem, as it is what regulates the current.

[Wil Rathke]

My 1999 had both an isolator module and an echo charger. The echo charger was located under a bedroom closet with the charger/inverter.

The isolator works with the alternator and provides 2 isolated outputs which connect to the chassis battery and the house battery. It only is active when the engine is running. The diodes in the isolator prevent either battery from draing the other.

The echo charger is a solid state device which connects between the positive side of the house and chassis batteries. It provides a small charge current to the chassis battery from the house battery. Since it is fused at 20 amps, the charge current would normally be less than 20 amps. Also, the voltage on the chassis battery will be about 0.6 - 0.8 volt less than the house battery. If it is connected wrong it will not work correctly. If this is a new condition, it would appear that the echo charger wiring was not at fault.