For some reason my coach battery will not charge when the engine is running. It used to. I have checked all of the fuses and all looks good. It will charge with the gen. or plugged into shore power. What else should I check???It's a 2011 Jayco Greyhawk.

Sounds as though your battery isolator is permanently isolating; troubleshoot that circuit. Often it's basically a solenoid (as in a heavy-duty relay) which is switched in at the appropriate times. The problem could be this solenoid unit itself, or the control wire/logic to turn it on, or a fuse in the line, or a connection at either end...Sometimes the isolator is not a solenoid but a heavy-duty diode device. Similar troubleshooting applies, though some of the specific details are a bit different.

Where do I find this battery isolator??

Hi,The isolator may be a relay or a diode. Is it a Ford Chassis?

The isolator can be mounted most anywhere that Jayco thought was appropriate. As an example, on my Coachmen (which, of course, could be entirely different), the isolator solenoid is mounted next to the coach battery under the entry steps, along with the main coach battery fuse and a little bus bar with connections for the converter, the main DC distribution panel (via the battery disconnect switch), etc.I gather that not infrequently the isolator is mounted somewhere under the hood.If you have an emergency start switch, pressing it causes the isolator system to temporarily un-isolate the two batteries. If you have someone press and release it you might be able to locate the isolator by listening for a relay/solenoid clicking on and off.

Coach Battery | Good Sam Community

14 Replies

Cruisineasy
Explorer
May 28, 2015
Yes Ford. E450 chassis
pianotuna
Nomad III
May 28, 2015
Hi,

The isolator may be a relay or a diode. Is it a Ford Chassis?
Cruisineasy
Explorer
May 28, 2015
Where do I find this battery isolator??
DrewE
Explorer III
May 28, 2015
Sounds as though your battery isolator is permanently isolating; troubleshoot that circuit. Often it's basically a solenoid (as in a heavy-duty relay) which is switched in at the appropriate times. The problem could be this solenoid unit itself, or the control wire/logic to turn it on, or a fuse in the line, or a connection at either end...

Sometimes the isolator is not a solenoid but a heavy-duty diode device. Similar troubleshooting applies, though some of the specific details are a bit different.

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Coach Battery

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