Troubleshooting Help - No 12V power and we’re leaving for a weekend trip in two days!

[chris_kelly]

Fellow Airstream’ers -

Searched the forums but couldn’t find anything relevant.

I started an install of two battle born batteries - the heated version since I thought I’d be able to drop them in to replace the current batteries. That didn’t work.

So I moved them inside. Just finished all of the cable runs - except for the hitch jack - and go to switch the system on but no 12v power is flowing.

I also installed the WFCO 8950L2-MBA to charge the batteries. When I plug into shore power the fan makes a loud clicking noise then stops. I’ve ordered a replacement already. I plan on reinstalling the OEM converter to test that.

I checked the connections and I have power from the new batteries into the gray 12v distribution box. I checked between the new battery cut off switch as well. Again consistent 13.35V using the voltmeter.

The red light is on for the master disconnect near the door.

What am I missing?

[pmclemore]

Does the red light mean that you are in "store mode"?

Pat

[chris_kelly]

Originally Posted by pmclemore

Does the red light mean that you are in "store mode"?

Pat

Yeah. It does.

I tried putting it use mode but nothing.

[lsbrodsky]

If you are connected to shorepower, the light will be red all of the time. No shorepower, it is red only in use. Do you have 12vdc coming out of the converter or does your post indicate that the converter is dead/disconnected?

Larry

[GCinSC2]

Time to print the 12VDC (hope it's in the manual) wiring diagram and follow the circuits?

[chris_kelly]

Originally Posted by GCinSC2

Time to print the 12VDC (hope it's in the manual) wiring diagram and follow the circuits?

Figured that as much.

[GCinSC2]

Chris

You already deep in modifications and have a meter so looking over anyone’s shoulder and forum diagnose is tricky.

Also sounds like a great time to document the mods for future troubleshooting and the next mods.

Good luck.

Gary

[chris_kelly]

Originally Posted by GCinSC2

Chris

You already deep in modifications and have a meter so looking over anyone’s shoulder and forum diagnose is tricky.

Also sounds like a great time to document the mods for future troubleshooting and the next mods.

Good luck.

Gary

Yeah. I hear ya.

So took the voltmeter and was getting consistent 13.3V past the converter charger but when I checked past the blade fuses the voltage dropped. The battery disconnect switch was red regardless of whether there’s power or not.

I thought it was the solenoid but didn’t seem to do the trick when I took the positive lines and connected them to one another.

The conundrum is when I plug to shore power the 12v circuits work but not when I’m on battery power. Or at least the lights do. And the pepwave modem.

Im really out of ideas now.

[wulfraat]

Have you checked the bus bars and disconnect solenoid for a loose wire? Sounds potentially like the batts pos or negative cable is not tightly connected to the bus bar.... I would go there next if you haven’t already checked the physical connections. Same with the 12v DC fuse panel, which connects to the bus bar downstream... check the physical connections on the battery terminals as well.

[rmkrum]

WARNING: Disconnect battery cables at the battery (negative cables first) BEFORE you swing wrenches around the buss bars and use/store switch. One false move and you can have lots of sparks or fire in that area. Been there, done that, no fun. Tends to melt stuff, including wrenches.



Master battery cutoff switch (this is mine) is a darn fine idea when you play with 12 volts DC power with plenty of ‘grunt’ behind it. This cover is lockable for protection against ‘helpful’ folks. The wiring from battery to switch is protected by an 80 amp MRBF fuse directly bolted to the battery terminal.

Yes, I’m a bit paranoid about controlling electrical powered 12 volt systems with honking big batteries in them. Two GC-2 6 volt batteries in series can deliver hundreds of amps for a short time.

[chris_kelly]

Problem solved!

So when I rewired the charger converter I had reversed the +VCC and battery + connection from the solenoid.

Now it makes so much sense why the 12V circuits functioned when I was plugged into shore power. The converter worked.

Here’s the kicker. My wife wanted to see what the issues were and when I was walking her through the path from the battery she asked me to test to the board where I was testing from the fuse board out.

[GCinSC2]

Now get SWMBO to initial and date the revised wiring diagram.

Congrats

Gary

[chris_kelly]

Originally Posted by gcinsc2

now get swmbo to initial and date the revised wiring diagram.

Congrats

gary

swmbo?

[JonDNC]

Originally Posted by chris_kelly

swmbo?

She who must be obeyed

[GCinSC2]

Jondnc he be smart.

Gary

[chris_kelly]

Originally Posted by JonDNC

She who must be obeyed

Woot woot.