Chassis Electrical Issue

DRPNGOUT · 01-24-2016, 11:18 AM

After being in the park for the last couple of months I decided to run the engine for a few minutes. As I've done a hundred times before, with the jacks down, slides out, and hooked up to shore power, I turned the ignition key and with a strong crank the engine started nicely. After literally 5 seconds, the engine stopped running. I turned the key out of the start position to off and then back to start and nothing happened. Now nothing electrical to the chassis has power, the fans, the radio, the map lights, the outdoor lights. Turning the key to accessory or to on does not illuminate any lights on the driver console. I checked the chassis battery with a volt meter and get 11.7 volts across the terminals. Everything in the coach is working properly.

My hunch is either a fuse has blown or a relay is stuck but I don't profess to know too much about this kind of thing. Does anyone have any ideas before I start trying to solve this?

The rig is a 2011 Georgetown 360 with the Ford V10 chassis.

Let me know if you have any questions.

northstar1960 · 01-24-2016, 11:30 AM

at 11.7 volts your battery is discharged

lbrjet · 01-24-2016, 11:40 AM

Yep, time for a new one.

2010 F250 5.4L 3.73
2011 Flagstaff 831FKBSS
Equal-i-zer 4pt 12K

bubbles · 01-24-2016, 11:42 AM

Don't know why the engine shut down but just in case, have you tried your emergency start also.

DRPNGOUT · 01-24-2016, 12:44 PM

That is part of the mystery, pushing the battery boost button and turning the ignition key does nothing.

I thought it was more than a dead/weak battery because it started the engine. I thought that I would be getting at least dim map lights or a dim radio backlight.

bubbles · 01-24-2016, 12:57 PM

Well, once the engine started the battery was no longer needed anyway. I don't know if a loss of an ignition fuse would cause the issue. Check the ford owners manual for the fuses. My car needs the ignition fuse for instrument display and to keep running. It's a 30 amp in my car.

bubbles · 01-25-2016, 01:47 PM

Although there was not a great deal of help on this issue please post the fix so that other GT V10 owners may benefit. Thank you.

SeaDog · 02-12-2016, 09:37 PM

On the F53 the chassis battery does not normally get charged by the converter. If your battery was at 11.7 that might not be enough power to excite the alt and keep the engine running. I think I would replace the chassis battery and start the coach and test the charging system. I keep a battery tender junior on my chassis battery of my Class A winnebago and let the converter recharge the coach batteries.

ScottBrownstein · 02-13-2016, 06:54 AM

I have been here before on my 1997 Fleetwood. If the boost switch doesn't work that means that the battery isolation solenoid isn't working. That also means that the converter is not charging the chassis battery and that the alternator is not charging the house batteries either. Obviously your converter is charging the house bank.

When there is no shore power and the engine is not running you should always hear the solenoid connecting when you press the boost switch! If not, there will be a lot of other things that do not work as predicted either and there will be all sorts of strange occurrences and you may not know where to start looking. I have personal experience that if you lose 12V to the engine on an F-53, the engine will stop running. This happened to me when running down the road at 60 MPH. Instrument bank went dark and I immediately experienced engine braking. When I pressed the boost switch the engine immediately began running again since it was getting 12V from the house bank through the isolation solenoid. I was then driving successfully but had to keep my finger on the boost switch. The solution was to start the generator and 1 minute later the converter powered the house which fired the boost automatically and I could take my finger off the button. Turns out I had a cracked battery lug on the engine battery that had given up but looked fine.

You have a problem with your battery isolation solenoid. If you don't drive much it could simply be that and nothing else. My old F-53 had dash voltmeter and I became accustomed to watching it after startup and looking for the quick and very perceptible voltage change that occurs seconds after start when the isolation solenoid kicks in and parallels the house bank with the chassis battery. My Georgetown doesn't have a dash voltmeter...but I watch the Trimetric and wait to see 14 volts or more from the alternator hit the house bank.

As far as the converter charging the chassis, most BCC makers added this functionality back in 1996 or '97. You will know that your RV is wired that way if you don't hear the solenoid click when you hit the boost switch when on shore power since the converter has already fired it automatically by applying 13 volts or more to the house bank.

To be sure there could be more complicated issues, but the failure of the boost switch bothers me a lot. Even if the ignition fuse or transmission lockout is a problem it shouldn't prevent the BCC isolation relay from firing(unless it has already been fired by the converter and the contacts are bad.) An ignition fuse wouldn't kill the chassis accessories. Make sure that there is 12 volts being applied to the isolation solenoid. If that doesn't fire it(no voltage drop across the heavy terminals...replace it with a continuous duty solenoid. I assure you the "sun will come out again" once that is done.

SeaDog · 02-13-2016, 07:47 AM

I should have mentioned that I was talking about an F53 of the 1996 vintage when I mentioned about the converter not charging the chassis battery. Scott may be on to something with the boost switch. In any case install a fresh chassis battery and do the checks good luck.

retired06 · 02-13-2016, 08:41 AM

I had this happen on my 2000 f150, everything went dead, what I found was a loose /corroded cable to the starter. Don't know about your vehicle, but it wouldn't hurt to try.

ScottBrownstein · 02-13-2016, 08:54 AM

Quote:

Originally Posted by retired06

I had this happen on my 2000 f150, everything went dead, what I found was a loose /corroded cable to the starter. Don't know about your vehicle, but it wouldn't hurt to try.

Could be that, as I had that as well. While we are "out there" the exact same symptoms that you are seeing will occur with a bad battery connection, INCLUDING THE CHASSIS GROUND (don't ask me why I know that.) However, in my experience (and running a 17 year old motorhome in Florida gave me plenty of it, you need to trust something. I agree, start with a fresh chassis battery and go from there. At least you know that the battery isn't the problem and most roads start with the battery.

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