What is the Aux Start switch for?

Stranger wrote:
pnichols wrote:


DaHose wrote:

I had to use mine once too, when my voltage regulator died. Pain in the butt to drive holding the button.

I have since installed a new battery combiner circuit that automatically bridges the batteries on startup. However, I also need to wire in the AUX button, so I can still hold it in to manually bridge the batteries if anything happens to my voltage regulator again.

Jose



Hmmm ... why couldn't one use a special cable they easily put together ahead of time that has a male 12V plug on each end. Plug one end into a coach 12V outlet and the other end into a 12V outlet on the dash in the cab.

This setup could backfeed 10-12 amps from you coach batteries into your chassis electrical system to maybe run the motor's ignition system (no lights on, though) so you could keep moving. The same thing could be done by running the coach's built-in generator to power a charger plugged into a coach 120V AC outlet with it's output plugged into a dash 12V receptacle as you drive.

This is just brain-storming on my part - never (yet) had to try it!

Stranger responded:

"Don't need to be "Snarky" but, I'd love to see the SPARKS using this method."

Hhhhuuuuuuh??

How is going from the coach batteries (via a cigarette lighter plug in the coach) to the chassis battery (via an always-hot cigarette lighter plug on the cab dash) going to smoke anything?


Also: "The same thing could be done by running the coach's built-in generator to power a charger plugged into a coach 120V AC outlet with it's output plugged into a dash 12V receptacle as you drive."

I do about the above all the time when the RV is in storage at home ... except the coach is on shore power instead of generator power. I plug a small charger/maintainer into a coach 120V AC receptacle and then plug the charger/maintainer's cigarette lighter plug adapter output cable into a always-on 12V receptacle on the cab's dash. This keeps my 6-7 year old chassis battery always fully charged so it doesn't sulphate and is therefore as good as new after all these years. ;)

I carry a Harbor Freight (yep, it is a cheapie), battery charger. If the chassis battery ever goes flat I'll light off the generator and plug in the charger . It has a 35 amp "Start" mode that will crank a dead battery after just a few minutes of run time. Never needed it but have loaned it out a couple of times to fellow campers who woke up to a dead chassis battery. {Also, a decent quality set of jumper cables should be in every vehicle.... but I digress}.

Someday I'll replace it with one of those combo units that jumpstart, charge and have a compressor built in. These are a little pricey, large and heavy so for now I'll just stay with the charger as I already have a 100 PSI compressor (also from HF, $39.)

:B

Bordercollie wrote:
Also....If the house batteries can't start the RV generator, it'll start when you press the emergency start and generator start button which connects house and starting batteries in parallel

On my Class C, that would take 2 people. The AUX START switch is by the driver's knee. The GEN START button is back, halfway down the hallway to the bedroom. However, starting the RV engine connects them too. I had to do that once to start the generator when a battery cable on the house batteries was a little loose.

Also....If the house batteries can't start the RV generator, it'll start when you press the emergency start and generator start button which connects house and starting batteries in parallel

If you're plugged into shore power a short piece of wire with alligator clips on each end bridging the two load terminals of the isolator relay will keep the chassis battery topped up.

pnichols wrote:

DaHose wrote:
I had to use mine once too, when my voltage regulator died. Pain in the butt to drive holding the button.

I have since installed a new battery combiner circuit that automatically bridges the batteries on startup. However, I also need to wire in the AUX button, so I can still hold it in to manually bridge the batteries if anything happens to my voltage regulator again.

Jose

Hmmm ... why couldn't one use a special cable they easily put together ahead of time that has a male 12V plug on each end. Plug one end into a coach 12V outlet and the other end into a 12V outlet on the dash in the cab.

This setup could backfeed 10-12 amps from you coach batteries into your chassis electrical system to maybe run the motor's ignition system (no lights on, though) so you could keep moving. The same thing could be done by running the coach's built-in generator to power a charger plugged into a coach 120V AC outlet with it's output plugged into a dash 12V receptacle as you drive.

This is just brain-storming on my part - never (yet) had to try it!

Don't need to be "Snarky" but, I'd love to see the SPARKS using this method.

Running the genny works, but feeding 12V from the coach battery to the combiner sensing lead will do it for my setup. A DPDT switch should work. One side is normal, the other side send's coach battery voltage.

Jose

DaHose wrote:
I had to use mine once too, when my voltage regulator died. Pain in the butt to drive holding the button.

I have since installed a new battery combiner circuit that automatically bridges the batteries on startup. However, I also need to wire in the AUX button, so I can still hold it in to manually bridge the batteries if anything happens to my voltage regulator again.

Jose

Hmmm ... why couldn't one use a special cable they easily put together ahead of time that has a male 12V plug on each end. Plug one end into a coach 12V outlet and the other end into a 12V outlet on the dash in the cab.

This setup could backfeed 10-12 amps from you coach batteries into your chassis electrical system to maybe run the motor's ignition system (no lights on, though) so you could keep moving. The same thing could be done by running the coach's built-in generator to power a charger plugged into a coach 120V AC outlet with it's output plugged into a dash 12V receptacle as you drive.

This is just brain-storming on my part - never (yet) had to try it!

Or be plugged to the campground and then start the RV, had to use mine once when the DW played CD's and did not turn the key back off, some times if you stay long enough and the battery is old the computer will drain the juice, and then you need the AUX to start driving.

navegator

gkainz wrote:
Starts the Aux in case the donkey dies ... :)

You beat me to it.