Battery Isolation Relay Problem?

[stillamook]

I have a 1999 fleetwood storm,31 foot motorhome on a ford chasis. It has 40,000 miles.
1. The alternator will apply a charge to the 12 volt chassis battery but will not charge the two 6 volt house batteries.
2. When connected to ground power the 120 VAC/12volt converter will charge the two 6 volt house batteries but will not charge the 12 volt chassis battery.
3. The house battery isolation relay makes the expected "clunk" sound when the rocker switch is cycled on and off.
4. Th chassis battery isolation relay does not make any sound when the rocker switch is switched on and off
5. My 12 volt chassis battery cannot be isolated and drains quite quickly without using the engine.
I did read another thread about a person having continuous problems with chassis battery isolation relay but did not get the final result and solution.

Help please.

[superk]

It sounds like it could be a problem with the relay, the switch that controls it, or the wiring between the two.

To eliminate the obvious, check all connections. Especially the chassis battery. Its entirely possible that you just have a loose battery terminal. Failing that, ensure that your chasis battery actually has a charge.

If all else fails, open up the BCC, I think there is a fuse for that in there somewhere, suggest to check it. After that, I think you are onto pinpoint tests.

I would call fleetwood up and get some wiring diagrams to help you if you havent already sorted out the issue.

[Old Bounder]

Originally Posted by stillamook

I have a 1999 fleetwood storm,31 foot motorhome on a ford chasis. It has 40,000 miles.
1. The alternator will apply a charge to the 12 volt chassis battery but will not charge the two 6 volt house batteries.
2. When connected to ground power the 120 VAC/12volt converter will charge the two 6 volt house batteries but will not charge the 12 volt chassis battery.
3. The house battery isolation relay makes the expected "clunk" sound when the rocker switch is cycled on and off.
4. Th chassis battery isolation relay does not make any sound when the rocker switch is switched on and off
5. My 12 volt chassis battery cannot be isolated and drains quite quickly without using the engine.
I did read another thread about a person having continuous problems with chassis battery isolation relay but did not get the final result and solution.

Help please.

Items 1 and 2 certainly point toward a problem with the isolator/aux start-charge solenoid (relay).

In items 3 and 4, you would be well advised to refer to those solenoids (relays) as the "Battery Disconnect relays" rather than "Isolation relays" as this could be very confusing to someone familiar with the BCC operation attempting to help troubleshoot your problem.

A quick test of the charging system, to determine if the Isolation/charge relay is BAD, is to press and hold the Aux Start Switch while observing if both battery banks are being charged by shore and alternator power.

Here is a very detailed troubleshooting and service document for your Battery Control Center) BCC.

Let us know if you need further assistance.
lou

[Rick_NH]

How did this work out? Lou, is an 02 fiesta the same? I've same problem with one relay clicking but neither battery charging.

[Old Bounder]

Originally Posted by Rick_NH

How did this work out? Lou, is an 02 fiesta the same? I've same problem with one relay clicking but neither battery charging.

Stillamook never returned, so we don't know if any of that helped or not.

Can you find the BCC in your Fiesta? I have no experience with those, but am willing to help. Does your aux start switch close the relay and cause charging on shore power or from alternator?

[Rick_NH]

I'm printing the information on troubleshooting in the other post. It's just what I needed, will let you know tomorrow,thanks
Ps I've another post that gives more information. I don't know how to link you to it. Odd thing is I uncovered it the other day for the summer. The starter batt was dead. It started with the aux boost. Got it into the driveway and shore power, downhill since. House batts at 3.23 volts, starter at 8. Neither will charge. Jump started the engine. Was charging chassis batt but not the aux.
The other day started with both right rear tires flat. Not having fun yet