Isolating the Coach battery, exterior 110v plugs, tieing in the Generator

[bagorider]

Sent: 5/26/2004

My 73 Indian has the generator out.  The wiring has been fooled with somewhat.  Anyway, I want to operate the axillary coach battery independently.  How did the original equipment switch over to 12v axillary power with no generator power?  I don't see any kind of switching mechanism other than the breakers to cut power to the converter.  How did the axillary battery switch on originally?  I'm planning to connect it directly to the fuse panel, but I'm sure I'll have to disconnect the converter output wires first or I'll risk smoking it?  Am I right??

Also, the converter has two output wires.  one goes to the fuse block, and the other one goes where? All I know is it goes down and I have not been able to trace it.  Any Answers?

[denisondc]

Sent: 5/26/2004

I don't think they all worked the same, but on my 72 the converter provided 12volts to the coach, whenever it was on, and a relay inside the converter would disconnect the negative side of the coach battery from ground. When the power to the converter was shut off, the relay flipped back, and connected the negative side of the coach battery to ground again. The positive side of the battery was always connected to my coach lighting.
The converter got its power either from the shore cable, or from the generator, whichever. There was a switch in the form of a double circuit breaker that connected the coach wiring and converter to either the shore power cable, or the generator wires. On my 72 this switching is done manually. Later on this was done with an automatic switch. Also later on the converters had a low-current battery charging feature. Mine doesn't though, nor does my genset charge the coach battery. I either charge it by connecting a battery charger to it, or by driving it with the batteries connected together with the dashboard switch. Yours might be different.

[Sea Hag]

Sent: 5/27/2004

My 76 Chief  works similar to the way Dave described with a relay that activates with 110 VAC automatically switching the 12VDC from the coach batt to the converter . The 110 side has no switch it's goes directly to the breakers so it's either present or off . the converter had a circuit board for charging the batt at .05amps ( not very useful for a low batt. ) the genny also charged the coach batt and won as the circuit board was smoked ( that saved the converter ) from the genny runnig to fast and producing 18volts + and some creative PO wiring . I have rewired the starting system and eliminated both the genny and converter from charging the batt and will rely on a 10 amp charger to refresh the batt . so I can control it . much faster anyway .I can also charge with the dual switch when traveling .   The later models like mine did away with a transfer switch for genny or shore power by mounting a 30 amp receptacle off the genny mounted in the compartment and you either plug into shore power or genny receptacle . Some times the simplest way is best . it just took them a while to realize it . - Sea Hag

[Sea Hag]

Sent: 5/27/2004

BTW  if you remove the screws from the front of the 12 volt side of the converter ( the one with the fuses on it )  It will tilt back and you should see the relay and be able to trace the score  to the coach batt .

[HeavyHaulTrucker]

Sent: 5/27/2004

Now my 1977 is just the opposite.  The negative side is always connected; it is the positive side that is switched by the relay.  When I start the genset, the converter voltage switches the coach to converter power; when the genset is off, the absence of converter voltage switches the relay to battery power.  Of course, the result is the same when shore power is substituted for genset power -- I have to unplug from the genset and plug into shore power manually.

[HeavyHaulTrucker]

Sent: 5/27/2004

When you pull the 12v panel down, you will see a big relay on the back.  Look at the right side of the relay, and you will see the vehicle and converter power sources; the vehicle 12v power is furthest from you, and the converter power is the closest to you.  The coach wiring side is on the left side of the relay, connected to the relay arm.  You will also see a secondary converter power lead connected to the relay coil, which is what causes the relay to switch from battery to converter power.