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jones101 · 08-05-2015, 04:17 PM

Engine was idling. When I closed the door and the step retracted the motor stopped. All power to the ignition switch was gone. No guages, fuel pump sounds, etc. I also noticed that the green LED next to the Chassis Disconnect Switch was out.

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Eventually I discovered a blown (melted) fuse up front in the Battery Control Center.

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Based on the color of the plastic blob I guessed it had been a 20 amp where a 10 amp was called for.
I replaced it with a 10 amp fuse. It's the one in the forefront of the pic at the end of the green leads. This gave me a green LED next to the Chassis Disconnect Switch again but when I turned on the ignition I only had power for about 5 seconds before the fuse blew again. If I install a 15 amp fuse (I know -not recommended) then I can get a few cranks of the starter before it blows.

edit: the Generator cranks and starts just fine.

How can I find out what circuit this fuse belongs to? Is there a diagram out there for an Intellitec 524-400 BCC?
Did the step retracting have anything to do with the engine stopping, or was it a crazy simultaneous event?

BTW- new to the forum, to class A ownership. I have lurked on the forums for a couple weeks and got a bunch of great information. I must offer thanks to all the members who so willingly assist others.

Denniscw · 08-05-2015, 05:04 PM

Just a thought. But if you look under near the steps there should be a connector for the steps. DO NOT LAY UNDER THE STEPS. Unplug the connector. If the steps are the problem the fuse should not blow.

jones101 · 08-05-2015, 05:16 PM

Quote:

Originally Posted by Denniscw

Just a thought. But if you look under near the steps there should be a connector for the steps. DO NOT LAY UNDER THE STEPS. Unplug the connector. If the steps are the problem the fuse should not blow.

Thanks for the suggestion. I just tried that but it still blows the fuse.

Looking at the way the fuse is connected in the BCC using wires rather than just pushing it in the board, I wonder if someone has "jumped" or modified things in the past?

I wish there was literature telling me what fuse # related to which circuit. I spoke with Thor today. They sent what they had, but it was not helpful to this situation. Maybe I'll try calling Intellitec in the morning.

Johndale · 08-05-2015, 05:46 PM

Why do the have a jumper wire for the fuse. That tells me they had an issue with the board and rigged it. I would remove the board and look at the backside.
Re looking at that board it looks like they added more wires to that board. Do you have a self start feature on your RV.

Sent from my iPhone using iRV2 - RV Forum

jones101 · 08-05-2015, 07:12 PM

Quote:

Originally Posted by Johndale

Why do the have a jumper wire for the fuse. That tells me they had an issue with the board and rigged it. I would remove the board and look at the backside.
Re looking at that board it looks like they added more wires to that board. Do you have a self start feature on your RV.

Thanks Johndale. I don't have a self start feature....as far as I know. I bought it from a private party who had not used it much and did not know much about it. I hoped that the giant stack of manuals would come in handy but there were not any schematics to be found. I can tell you all you want to know about recording your favorite shows on the VCR however.

I can't help but think there is a relationship to the step. There's some circuit that tells the step to retract when the ignition is on. Perhaps a short in that would cause the fuse in question to blow. Seems odd to think that an electric step can make you dead in the water. I'm just glad it happened in my driveway.

mgscott4 · 08-05-2015, 08:43 PM

You could go under your steps and unplug the 4 pin connector to the steps and see if it still blows the fuse.

I do know that there are 2 fuses for the Kwikee steps, a 20 amp and a 5 amp. If the 20 amp blows the steps do not work. The 5 amp is the switch fuse, if it blows, the steps open and close with the door, no matter what position the switch is in.

It is scary to think that one 10 amp fuse blows and shuts down the engine, Something must have been rewired. I would install a jumper across the chassis disconnect relay so that it never disconnects. My BCC manufactured by "Custom RV Products" has been recalled and the fix was to move a wire from switched to unswitched to effectively eliminate the disconnect relay. If you want to store the RV, get a wrench and remove the negative battery wiring.

Here some light reading that may help.

http://www.irv2.com/forums/f121/batt...ec-254567.html

http://www.irv2.com/forums/f121/thor...ll-169291.html

mgscott4 · 08-06-2015, 08:37 AM

Moderator---Double post, in the Workhorse section too.

jones101 · 08-06-2015, 10:23 AM

Quote:

Originally Posted by mgscott4

You could go under your steps and unplug the 4 pin connector to the steps and see if it still blows the fuse.

I do know that there are 2 fuses for the Kwikee steps, a 20 amp and a 5 amp. If the 20 amp blows the steps do not work. The 5 amp is the switch fuse, if it blows, the steps open and close with the door, no matter what position the switch is in.

It is scary to think that one 10 amp fuse blows and shuts down the engine, Something must have been rewired. I would install a jumper across the chassis disconnect relay so that it never disconnects. My BCC manufactured by "Custom RV Products" has been recalled and the fix was to move a wire from switched to unswitched to effectively eliminate the disconnect relay. If you want to store the RV, get a wrench and remove the negative battery wiring.

Here some light reading that may help.

http://www.irv2.com/forums/f121/batt...ec-254567.html

http://www.irv2.com/forums/f121/thor...ll-169291.html

Thanks mgscott4!
I'd rather do a manual battery disconnect if the trade-off is something like this.

I've been thinking about other variables that could contribute to this. I had just changed the serpentine belt. I don't recall having been too rough in there or bumping up against any wires. Once the belt was installed I ran the engine for 20 seconds to confirm the belt was seated and rolling smooth. Then in preparation for a throttle body cleaning I replaced the doghouse and started the engine again to allow it to warm up. It had been running for about a minute when I exited the coach, the step closed and simultaneously the motor quit.
So I wonder, did the steps have anything to do with it? Or perhaps I bumped something during the belt change that would cause this fuse problem? Perhaps since the fuse they had in was too heavy for the circuit, it took a while (building heat) to finally blow/melt and that's why the motor ran for a minute or so before stopping.

I've also read about ignition switch failures but I'm not sure that's where I should go yet.

I'm also keeping in mind that the LED indicator for the Chassis disconnect switch on the "Battery Storage Control" panel is only illuminated when the fuse in question is intact. How does that relate to power to the ignition switch? Could the disconnect switch have gone bad? If so, can I bypass?

jones101 · 08-06-2015, 04:05 PM

Well I learned a couple things.
1. someone has "rigged" a bypass of sorts which has failed. The jumper with the fuse in question goes from a 12v source (Converter relay) to the hot side of the fuse row on the printed board essentially back feeding voltage to the rest of the system.
2. The Battery Disconnect seems to have been replaced with a standard solenoid. I think the one on the right should be the same part as the one on the left. (see pic)

Now I wonder... How can I bypass the entire Chassis battery switching system? I am glad to remove the negative terminal during long term storage. I would like to retain the ability to charge the Chassis battery when I'm on shore power.

jones101 · 08-06-2015, 05:02 PM

I think it might be as simple as a bad solenoid causing the fuse to blow.

(see video)

The thing is, I don't think that's the right part. I think it's supposed to be the Intellitec switch. Maybe a tech or DIY did a backyard bypass when they could not quickly get the right part. I've ordered the part and will install it where it should be. Granted, this correct part is around $60 where a generic solenoid is about $10.
What remains to be seen is if there is another short somewhere in the system that I will discover upon re-energizing.

jones101 · 08-07-2015, 05:56 PM

I got the right part (Battery Disconnect Relay) and installed it. I was careful to test several recommended circuits before I energized it.
Once it was powered up I had my wife on the switches by the steps and my volt meter ready at the board. There are test points in the upper left of the board where one can confirm voltage is momentary and polarity is correct. Both the coach and chassis control circuits tested out fine.

I guess the long and the short of it is that the previous owner had a Battery Disconnect Relay failure and replaced it with a common solenoid. He then back-fed it with power in an attempt to keep it energized all the time.
I still don't know why it failed at the moment the steps retracted, but I'm SO glad it was in my driveway right next to my toolbox!

Thanks to all who contributed, spending time helping with suggestions, links, and diagrams. I'm glad I found the community!