Major electrical problems

[jackthebear]

We have major electrical problems with our 2003 Allegro.
Early this spring I reinstalled the coach batteries which had a trickle charger on them all winter. The chassis battery was dead when I went to start the unit (I had started it every 4-6 weeks over the winter and it was O.K.) Put the charger on the chassis battery and it wouldn't take a charge.
I replaced it with a new battery and everything was fine, or so I thought. A week later, I tried to start it and all the batteries were dead, boosted it and took it on a short drive and also found that the speedo didn't work! It had worked O.K. in the Fall.
Couldn't find any reason for the major draw, but I'm not an automotive electrician.
Took it to the only Ford dealer in Calgary that will work on MH. They of course put it on their diagnostic equipment and coudn't find anything and there was no draw on the chassis system. They said the batteries were probably not fully charged. They ordered a new speedo to the tune of $700.00 but it would take 2 weeks to get in.
When it came in, they went to bring in the MH to install it & the batteries were all dead. They then agreed that there may be an electrical problem. At 135.00/hr to trace.. Any suggestions would be appreciated.

[deandec]

I am no electrician either, but here is what I would do before paying some $135 per hour.

Recharge both battery banks.

Turn the battery disconnect for each bank to the disconnect position.

Try to operate the various components run by each battery system to see if current is still reaching that component when it should be disconnected.

If all is shut down ok, turn on the chassis battery bank. Then try to operate features that would normally be run by the house battery bank.

If the house bank features work, but the house bank is "disconnected" there may be a battery isolator that has failed and the chassis battery is running the house features. (I have had this type of problem.)

If that tests ok, then reverse the disconnect status of the battery banks and test the chassis features to identify any chassis features run by the house bank.

If that test is good and the shop could not find a draw on the chassis batteries, I would suspect that the new battery was not fully charged when you installed it.

And if you stored the rig with the house batteries in the "connect" status that you lost whatever charge they had in the meantime.

The above would mean that your batteries and system are ok, but need to be fully charged and the disconnects used.

If you have already done the above, I can be of no furthur assistance.

Hope you get to a resolution.

[jackthebear]

Thanks Dean, I'll try your suggestions. Hopefully....
Stewart