Emergency Start switch didn't work

Another freakin' needless nightmare. An intermittent duty solenoid should be protected by a circuit breaker not a fuse.

EMERGENCY START BUTTONS should have THREE WIRES BASIC CONNECTION.

1. The wire that runs to the solenoid
2. 2nd wire that runs to the CHASSIS BATTERY. 2 and 3 connected to the same switch pole
3. 3rd wire that runs to the house battery bank. 2 and three connected to the same the same switch pole.

The suitably large diodes prevent electricity from bleeding between battery banks.

When I installed these systems I used TWELVE GAUGE cross-link wire and a 15 amp breaker. A 7-1/2 amp fuse is TOO SMALL. Try and convince me a 195X14 tire is suitable for a Winnebago Class A. This design error is careless engineering. Intermittent duty starter solenoids are low resistance meaning the coil can suck 10 amps for some model solenoids. This is why a 25 amp rocker switch is vital. All this nonsense is due to penny pinching manufacturing limitations. You can fix all of it once and forever if you wish to. The @#$%^&! circuit breaker should be placed next to the emergency start solenoid, not between the passenger's knees. Feed it with dual dioded feeders instead of the switch if you want to.

Cole-Hersee 30-amp rated rocker switch.

If there is power in any of the battery banks when you push the button the engine will crank.

Wire 2 has a suitably large RECTIFIER DIODE placed inline. Cathode to switch
Wire 3 DITTO. A 2nd diode cathode on switch side.

The fuse was in the little black box that Joe laid on top of the brake fluid reservoir. it was tucked underneath everything.



This is the circuit drawing


Drawing shows TWO 7.5-amp fuses. I take it the lower one was the blown one in this case.

Where, physically, was the Fuse?

Could you post the diagram Mike emailed you?

Thanks for the follow up.

Problem solved: I found the right person a Thor that located the diagram of the emergency start circuit and emailed it to me.
The problem was a blown fuse 7.5amp between the switch and the solenoid. Don't think I would have ever found it without the drawing. Many thanks to Mike at Thor !!!!!

Getting accurate electronic schematics isn't just a Thor issue ... on the bright side most RV's are pretty generic and electronic issues are generally not unique to any particular brand.

Thanks to everyone for the input. I haven't had time to trace problem do yet but I will post what I find when I get to the bottom of it.

I'm so irritated with Thor customer support. This is the 3rd different electrical problem I've had and tried to get some help from them.....with no luck. Below is their response to this problem

"Warranty Support
Jul 23 (2 days ago)

to me

Joe,
I could not find a print on the emergency start circuit. If the batteries went dead then there is a possibility that the voltage was to low o engage the solenoid.
Thanks,
Thor warranty support"

Do they just send there assemblers out to the shop and say "Build me one of these"????? lol

My motorhome uses an interconnect solenoid and there's a 150 amp fuse in the wiring. If the chassis battery is totally dead it can draw enough current to blow the fuse when the solenoid engages.

Here is a link for a Fourwind's Manual that may help you. On page 72 there is the BCC Fuse list P1-1 is Aux Start Switch fuse.

Not sure why your Chassis Battery went dead so, something is not working correctly with your Charging System and needs to be repaired most like.

Good Luck on the hunt,
DJ

othertonka wrote:

haddy1 wrote:
Most "aux start switches" don't actually switch battery banks, they tie the banks together. If your chassis batteries are really low, or bad, the switch may have to be held for some time because the bad batteries draw most of the initial load.

I agree with this post. push and hold the button a little while and let the two batteries equalize. It is kind of like using jumper cables, hook up and let the jumper vehicle run a little bit before trying to start the dead vehicle.

While holding the button down, you should notice the volt meter on the dash rise as well right? I know on mine you do, but when I used the aux start the battery was just low (not dead), so not sure if that makes a difference.