My Aux Start Battery Switch Is Not Working

Yellowboat · 03-21-2014, 12:20 AM

I have a 2006 Winnebago Sightseer 29R on a Ford Chassis. When I push my Aux Start Battery Switch nothing happens.

I’m having chassis battery problems. Not sure if I have a bad cell in my battery, or if I have a parasitic drain on the battery. Chassis battery is about three years old. I cleaned the connections this past summer and once again this afternoon to make sure I have good connections.

Today, after traveling 200 miles, and sitting approximately 20 minutes the battery showed 10.5 volts. After a jump start the battery showed 12.47 volts. Tomorrow I will stress test the coach battery.

All that said, my Aux Start switch is not working. I have been using jumper cables to start my engine. I suspect a fuse or a solenoid valve. I looked in my manuals and I didn’t find a fuse for the Aux Start Switch. And I didn’t see a solenoid valve in my battery compartment.

Are there any Sightseer owners, or Ford F53 owners who know where I should look for a fuse or solenoid?

Thanks. Safe travels.

JD

cc8375 · 03-21-2014, 05:10 AM

Went through a similar problem with my coach. Battery was not even a year old. Replaced the Chassis battery and the problem solved. The battery apparently had a "Soft Short". Whenever the Chassis battery was tested it tested OK. Test numerous times at a RV shop, Truck stop and my own test. Many thought there was a parasitic drain on the battery which was drawing it down. I added a a Battery Prog Brain to eliminate a drained battery. Next time out Battery was Dead! So it was the battery.
When the Battery was in this state the Aux. Switch would Not work.
Prog website below
homepage

Ray,IN · 03-21-2014, 10:40 AM

I'm sure you already know the Aux. start switch is a momentary switch connecting your house batteries to your coach battery, and must be held in while starting the engine.

RoadHappy · 03-21-2014, 01:41 PM

Any advice will be appreciated....My 2001 Itasca Horizon is fairly new to me and currently stored with no shore power. As I was extending the slide yesterday, it slowly came to a halt less than 1/2 extended. I went to start the engine to build up air pressure, but it would not start. No dash lights, headlights, etc. The neutral gear light was not on in the shift pad, but the "mode" light was on and a symbol that I did not recognize across the top. I also tried the auxiliary start switch, but nothing. The instrument gauge near the rear of the MH showed 11.2 volts for the chassis battery. Any ideas what I should look for? Thanks.

Yellowboat · 03-21-2014, 08:15 PM

Thanks.

CC8375: I took the battery out and had it checked. They said that it failed a load test so I bought a new one. I guess I don't need Aux Start till I have a problem with this new battery. I will wait till we get back home.

Ray,IN: Yes, I know to hold the switch while starting the engine. It didn't work so I jumped from my house batteries.

RoadHappy: I found that my jacks and my slides will not work with a bad coach battery. I was putting down my jacks and they stopped working. I had my wife put out the slide so I could check my jacks. Slide went out. We always wait till shore power is connected before extending slides. I asked her to pull in the slide after I checked the jacks and she said it would not come in. The parking brake light was on. That was when I decided my problem was the coach battery and not the jacks or slides. Once I jumped from my house batteries and started my engine jacks and slides worked normally.

Safe travels.

JD

CJBROWN · 03-21-2014, 10:25 PM

The wiring diagrams are readily available for that coach. I can't imagine 'bago built the F chassis any different than the W chassis - the latter runs slides on the chassis batts. Jacks too. So neither should be run without starting the engine first so there's juice for them. Otherwise you're running down a fairly small and vulnerable to failure battery.

What most folks fail to realize is that an engine starting battery cannot tolerate being run down - it needs to be kept at peak charge all the time. If it runs down it will fail sooner rather than later. They have thin plates for a burst of starting energy - letting them run down will sulfite the plates and they won't hold a charge. It's not uncommon for start batts to die in three years or less. Keeping a smart charger on them when stored will help extend their life.

I ended up changing over my 10watt solar panel to charge the chassis batt instead of the house. The house now stays plugged in with a propber coverter/charger unit.

OP and Roadhappy both are likely have dead chassis batt(s) - replacement is likely to fix everything. Just keep them charged up.

RoadHappy · 03-22-2014, 06:21 AM

Thanks both for replies.

DancinCampers · 03-23-2014, 09:06 PM

On my 03 Adenturer the Aux solenoid was behind a false wall on the top entry step, next to the bridging solenoid. The wiring diagrams for your coach should put you in the right direction.

They should also let you know if it is energized from the house or chassis battery.

ChasA · 03-24-2014, 08:31 AM

I had a 2006 29R. The aux and battery disconnect solenoids are in the tiny compartment above the propane tank. The solenoids are in a black box on the left wall of the compartment. It's very difficult to work in there. Good luck.

Yellowboat · 03-27-2014, 10:10 PM

Thanks CJBrown. I have always made sure I had shore power when operating my slides. And I would usually have my engine running when using my jacks but not always. Now I will have shore power on and engine running for jacks and slides.

Thanks DancinCampers but ChasA nailed it. I have a black box as ChasA describes and it is labeled to contain the battery solenoids.

We just returned from the warm and dry south to damp and cold Seattle. I am in shock and will wait for warmer weather to look at the system.

Thanks everyone for the help and safe travels.

JD

jerichorick · 03-28-2014, 07:46 AM

Yellowboat, please include the model of your coach in your signature. I had a similar failure on my last coach and found it was the isolation solenoid, the one that switches with the Aux Battery switch, was bad.

When the engine is running, what voltage do you see at the start batteries and what voltage do you see at the house batteries? The aforementioned relay switched as needed to charge each bank. No worky? No chargy.

I suggest that you buy an inexpensive DC clamp meter and keep it with you. If you do have a parasitic drain on your batteries this will see it.

Hikerdogs · 03-28-2014, 10:02 AM

As DancinCampers said the solenoid that connects the house batteries with the starting battery is behind a panel at the rear of the top step. This solenoid is supposed to be engaged anytime the engine is running to charge both the house and starting batteries.

The easiest way to see if it's working is to go to the OnePlace monitor when the engine is running. If the alternator is putting out current the starting battery should read in the 13.2 to 13.4 volt range. If the solenoid is working the house batteries should show a similar voltage. If the house batteries still show 12.4 volts or below the solenoid isn't working.

If the solenoid is bad it's easy to replace. You can get one at almost any RV parts store. It looks like the old Ford starter solenoid. The main difference is the ones used in the rv's have a 100% duty cycle. It's engaged anytime the engine is running. Make sure to get the proper one. The normal Ford starter solenoid has about a 5% duty cycle and will overheat and burn out in short order. We replaced ours with one from Trombetta. It was about $25.00 and took only a few minutes to install.

Don't be fooled thinking the solenoid is working just because you hear the clunk of the solenoid engaging. Often times the plunger forms a carbon film on the contact end from years of use. The carbon acts as an insulator preventing the flow of electricity to the batteries. Even though the mechanical part of the solenoid is working there is no current being transferred to the batteries.

jerichorick · 03-29-2014, 07:00 AM

Quote:

Originally Posted by Hikerdogs

As DancinCampers said the solenoid that connects the house batteries with the starting battery is behind a panel at the rear of the top step. This solenoid is supposed to be engaged anytime the engine is running to charge both the house and starting batteries.

The easiest way to see if it's working is to go to the OnePlace monitor when the engine is running. If the alternator is putting out current the starting battery should read in the 13.2 to 13.4 volt range. If the solenoid is working the house batteries should show a similar voltage. If the house batteries still show 12.4 volts or below the solenoid isn't working.

If the solenoid is bad it's easy to replace. You can get one at almost any RV parts store. It looks like the old Ford starter solenoid. The main difference is the ones used in the rv's have a 100% duty cycle. It's engaged anytime the engine is running. Make sure to get the proper one. The normal Ford starter solenoid has about a 5% duty cycle and will overheat and burn out in short order. We replaced ours with one from Trombetta. It was about $25.00 and took only a few minutes to install.

Don't be fooled thinking the solenoid is working just because you hear the clunk of the solenoid engaging. Often times the plunger forms a carbon film on the contact end from years of use. The carbon acts as an insulator preventing the flow of electricity to the batteries. Even though the mechanical part of the solenoid is working there is no current being transferred to the batteries.

Well stated and very clear. The contacts are replaceable in some cases, but generally not worth doing. I also recommend silver contacts and 100% duty cycle. I think my replacement on my last coach was about $35. In my case, the solenoid was not easy to reach.

For safety sake I recommend disconnecting the negative battery lead on both banks to ground. Make certain all voltage is off the solenoid before changing it. I don't think you want to practice arc welding 101

.

Yellowboat · 04-05-2014, 09:38 PM

I haven't checked my Aux Battery Start as of yet.

We arrived home from spending the winter down south a week ago last Wednesday. Our motor home was parked in our driveway for 8 days and when I started the motor it turned over with no problem. While on the road I had to plug in my Battery Minder and then after 4 or 5 days I would have trouble starting my engine. When I replaced my old battery I bought the biggest battery they had.

When the weather turns nice and I get all of my yard work done I will check out my aux start solenoid. Thanks for the procedure Hikerdog. I did not realize the solenoid was energized when the engine was running.

Jerichorick, I purchased a clamp meter that will will carry with my volt meter for any future repairs.

Thanks for the help. I learned a lot on this site as always.

Safe travels.

JD

jerichorick · 04-06-2014, 09:01 AM

JD, this may sound strange, but I am a bit jealous. I have used the meter when I worked with generators, given it as a gift, but as often the case, have not bought one for me. It is on my wish list. I have managed to get along without it but without doing things the direct way as would be possible with the meter. Your troubleshooting will go so much faster having a clear indicator of 'battery discharge' or not.

Thanks for keeping us posted. We all look forward to the success story.

Rick