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tomgrigsby · 10-09-2020, 03:28 PM

I've been troubleshooting why the house battery cut off switch won't work unless the chassis battery disconnect is off. While checking the bird relay I found no 12 volts on the chassis battery input connection. Hand over handed the cable and found it on the NEGATIVE post at the chassis batteries. The dealer replaced all the batteties and must have have done it. There's no continuity through the relay when it is energized, so I'm guessing it toasted the contacts the first time it energized after battery replacement. It would have connected house battery positive to chassis battery negative. Not good. I'll replace the relay and keep chasing the other problem.

iluvuk · 10-15-2020, 12:11 PM

ouch. bad dealer

Bunni · 10-15-2020, 03:45 PM

Our BIM cables were backwards from the factory. We couldn't figure out why our chassis batteries only charged when the engine was running. Tested the cables and figured out they were switched. All is well now.

tomgrigsby · 10-16-2020, 05:02 AM

Quote:

Originally Posted by iluvuk

ouch. bad dealer

The positive cable at the chassis batteries that went to the bird isolation relay wasn't marked red. Apparently that wasn't noted when they replaced the batteries and so just hooked up black to black. It blew out the isolation relay. I've changed the relay and it's working now. I'm going to put some red tape on the cable so hopefully I won't mess it up in a couple of years.

iluvuk · 10-16-2020, 09:16 AM

Quote:

Originally Posted by tomgrigsby

The positive cable at the chassis batteries that went to the bird isolation relay wasn't marked red. Apparently that wasn't noted when they replaced the batteries and so just hooked up black to black. It blew out the isolation relay. I've changed the relay and it's working now. I'm going to put some red tape on the cable so hopefully I won't mess it up in a couple of years.

I think you are lucky that is all that blew out. Good catch.

RetiredBob · 10-16-2020, 01:01 PM

I see things haven't changed in the last ten years! My BIRD was mis-wired from the factory so the chassis battery wouldn't charge when plugged in to shore power. Dealer rewired it and it's worked perfectly ever since.

tomgrigsby · 10-17-2020, 06:29 AM

I still have one issue that bugs me. At the bird there is a fuse noted in my earlier posts that connects house battery voltage to the bird for monitoring. It has a splice and a wire going to the courtesy lights (those little round ones at the floor in bath area). Those lights are on the chassis battery, so the splice effectively connects the house and chassis batteries together and keeps me from turning off house power unless I also turn off chassis power, and vice versa. That can't be right, but on another post, an owner of a freightliner chassis sent a pic of his setup and it's wired the same way.