Community Forums

TT_Vert · 05-18-2021, 01:34 PM

Does anyone have a schematic for this particular circuit? It's a 3 wire circuit. Center pin is ground. To kill, it bridges center and right pins (Grounding the right pin). To start, center and left pin. Kill works at the interior switch but start does not. This all started after I had integrated a BIRD into my setup. I won't get into all the details but I did speak w/ intellitec about this as well as another very knowledgeable BCC repair company. I suspected back feeding of 12V from the BIRD to the aux start switch so I added diodes to the two wires that feed the +12V side of the aux solenoid (One from aux start switch and one from BIRD). So far the problem has not come back (post diodes) but i really want to understand this circuit. When the problem was occuring I tried to bridge the center pin and ground (bypassing switch) and nothing happened. Also tried to apply +12Vdc to that "start" wire but no dice. if I started it manually at the generator and killed it bridging the center and right pins it worked. The actual switch is good and does work for killing just not starting. I tried to trace wires but given they are all white I did not have good luck at all. I did confirm those wires do not go directly to the generator at least. Oddly I applied 12V to the light that illuminates when gen is running and that would crank/start it. Does anyone know if the BCC controls gen start at all and if not, how exactly does the gen start circuit in cab work? I feel it may be grounding a relay to start and then just grounding the coil to kill. That'd make sense however when I tried to bypass switch and ground that wire I still got no start. There has to be more to this circuit than I am a aware of.

Any help would be greatly appreciated.

Dave

Jim_HiTek · 05-19-2021, 07:41 AM

I owned a '94 Fleetwood Bounder with diesel engine. The BCC had nothing to do with the remote start and stop of the generator. My STOP/MOM/START switch on the dash wouldn't stop the generator but would start it okay. The switch on the genset worked for both functions.

I pulled the control card and drew up a schematic but I can only find this partial schematic ATM. I am getting ready to head north this morning so don't have time to search for the original completed drawing, I'll do that as soon as I have the time. For now, this is what I have on my RV Repair blog: RV Repair Blog.

What my issue turned out to be was one terminal in that brown connector on the right side of the board corroded through causing an open circuit in the 'Stop' lead. An unusual problem to be sure but if you have a meter, pull your card and check that. I really had to work at finding it as it was so unexpected. Once I found it, I was cussing the engineers for using such a flimsy connector in an industrial design.

There's an unused terminal on that connector that you can use to reroute and solder a jumper to to get your system working again...easy job if you have soldering skills. Hard part was scraping off all the conformal coat on the card to get to the solder pads. Wire from the dash switch is carefully released from the mating connector and moved over to the empty wire hole that matches the new wire position.

I'll try to find and post the full schematic when I stop for the night this afternoon up in Fallon, NV.

TT_Vert · 05-19-2021, 10:35 AM

Quote:

Originally Posted by Jim_HiTek

I owned a '94 Fleetwood Bounder with diesel engine. The BCC had nothing to do with the remote start and stop of the generator. My STOP/MOM/START switch on the dash wouldn't stop the generator but would start it okay. The switch on the genset worked for both functions.

I pulled the control card and drew up a schematic but I can only find this partial schematic ATM. I am getting ready to head north this morning so don't have time to search for the original completed drawing, I'll do that as soon as I have the time. For now, this is what I have on my RV Repair blog: RV Repair Blog.

What my issue turned out to be was one terminal in that brown connector on the right side of the board corroded through causing an open circuit in the 'Stop' lead. An unusual problem to be sure but if you have a meter, pull your card and check that. I really had to work at finding it as it was so unexpected. Once I found it, I was cussing the engineers for using such a flimsy connector in an industrial design.

There's an unused terminal on that connector that you can use to reroute and solder a jumper to to get your system working again...easy job if you have soldering skills. Hard part was scraping off all the conformal coat on the card to get to the solder pads. Wire from the dash switch is carefully released from the mating connector and moved over to the empty wire hole that matches the new wire position.

I'll try to find and post the full schematic when I stop for the night this afternoon up in Fallon, NV.

Where was this card you have shown located? To clarify I have it working now and I really didn't think it was something to do w/ the BIRD and BCC but when I disconnected the aux start hot side wiring I was able to get it functioning again. I only stumbled upon this because I jumpered the two start wires on the inside genset start switch and toggled the aux solenoid switch in the RV and it would crank. This indicated to me some backfeed somewhere on the aux side. The aux start switch in RV (To crank off of coach batteries) is fed by the aux side batteries which has a fuse through the BCC. I was starting to think the 12V was backfeeding on that circuit when it was not energized and wreaking havoc. No idea how/why as from what I can see if the generator start does not go through the BCC at all. HOWEVER, it seems the gen start is ground referenced and perhaps something was backfeeding to ground via the BCC causing this. Only thing that makes sense to me.

Dave

Jim_HiTek · 05-19-2021, 05:38 PM

Just got set up at a seedy RV park that is charging $48/night for 50 amp with a dicey socket. This is a $35/night place, MAX.

That board was under the cover on the generator. Pull the cover off, and it's right there. On my '94, the gen was mounted N-S in a basement compartment so if you followed my link above you'd have seen where Fleetwood mounted it. You can see the Start/Stop switch on a panel facing out, and under that panel was that board. See that bundle of white wires? That's plugged into the brown connector that corroded. I just moved the 'Stop' wire to an unused hole and soldered a jumper on the board.

Here's the pic:

TT_Vert · 05-20-2021, 08:35 AM

Thanks, your setup is definitely different than mine. Last week when I was testing i did see white wires in 3 separate plugs at my genset below the switch but none of them had continuity to the remote on/off switch in the RV.

Dave

TT_Vert · 08-26-2021, 01:38 PM

So I went through everything today. Took out the control board and checked continuity of all traces and fully understood the wiring. In reality if the remote start does not work it's either the wiring from switch to the board or the plug/traces between the plug and the onboard start/run switch. Both use all the same electrical components to start the genset. So if it starts at the genset switch it should start at the remote switch unless there is an issue w/ the wiring between the two as that appears to be all there is.

With that said i checked all connections at genset control board and they looked like new w/ no corrosion. I still did clean them all and put quite a bit of dielectric grease in there to prevent any corrosion. I then followed the wires up to the front and found they go into a connector near the firewall which was completely wrapped in electrical tape. I have to assume they did this since the connector was not a weatherpack or other weather tight type of connector (WHY???). Somehow moisture did get in there and start to corrode things. At this point I thought I found my issue. De-pinned each one and cleaned it and reassembled w/ lots of dielectric grease. Went to start thinking this was the problem but NOPE!! I go to that plug at firewall and jumper red/brown to simulate start (on both sides of the connector just to make sure I didn't have some odd intermittent plug connection) and it starts. Checked continuity of each wire through that plug, it's good. This pretty much tells me the switch has to be the issue but I really cannot see how/why. I've never seen an intermittent switch like this nor one that'd just start working if i flipped the aux/main a bunch of times. Perhaps it's just causing enough of an arc to fuse the contacts together enough, I don't know. Of course right now the switch is working so i cannot jumper the switch at that plug to see if it starts. if it does then i know for a fact it's the switch but until if starts acting up again I cannot do that.

Dave

TT_Vert · 08-29-2021, 02:08 PM

Finally got that dash switch removed and disassembled. The contacts are as clean as the day it left the factory. Also tested w/ meter and continuity is still fine which again makes me feel my issue was not the switch in my case. With that said when I pulled the switch it was functioning again so perhaps there is some weird thing going on w/ the spring that pushes the contacts together during momentary activation. The PN on my switch is 511.066 and seems non existent when googling for it.

Dave

TT_Vert · 09-06-2021, 11:55 AM

For those who are following this and for my future reference:

The switch checked out fine upon disassembly. It was quite a confusing diag on this one. It would work for a while, then stop, if i were to toggle main/aux a few times while wifey held genstart in cab it'd eventually work. Disassembled switch even though it tested fine w/ meter and it looked brand new so I knew it was not the switch at this point. When I would go to the plug I pictured above and jumpered it would always start which led me (errantly) to believe the issue was between that plug and the switch so I started to look into that wiring.

After more testing when it was not working again today I removed and jumpered the ground to the start wire at the switch and started playing around. I started with the wiggle test under dash and got nothing, there was no plug between the switch and engine compartment and I saw little to no way a wire would get damaged under the dash. Went back to my suspect plug under hood (I showed earlier in this post) and on chassis side of that plug I jumpered ground to start and it started w/ my meter probes. WTF?? That tells me the problem is between that plug and the switch. I then went back in and double checked under dash again, followed loom and discovered there were maybe 3' of wire between that plug and the switch and it was fine. I then took my pliers to each wire in the suspect plug and started pushing the plug together and wires towards the opposite contact and sure enough the gen cranked. Tried to de-pin that start wire from chassis side of plug and it broke. Bingo! Corrosion caused the terminal to basically break in half. So what was happening (And throwing me off) was when I were to jumper w/ my meter probes I was actually pressing that broken terminal together enough to ground the start wire which is what threw me for a loop. That explains why it started sometimes and not others from cabin gen start and I have to speculate that when cycling main/aux switches while wifey held the gen start switch just caused an arc after enough times to allow enough continuity to ground the start side.

Fleetwood used a non-weatherproof connector here and it would have probably been ok had they not covered the entire connector with electrical tape as water entered and could never get out quick enough to not cause corrosion. I'm going to cut that plug out tomorrow and wire in a weatherpack and never have another issue. So many corroded wires on this RV have caused me headaches thus far.

Tomorrow is now today (9/6/21):

Okie dokie, I think i can close this chapter. Cut the old plug out and installed a weatherpack 4 pin I had from my old factory five I wired. Three of the wires had corrosion on the exterior copper. Best I could do is take an exacto and scrap it off where I had exposed copper for crimping on the new terminals. I don't know how far into the wire the corrosion goes but if I have issues down the road I'll keep in mind that there was some corrosion. Fortunately it did not go down to the core of the strands so I don't see it being much of an issue in the future. The good news is, if this thing is ever submerged in 6' of water, this connector will probably stay dry/corrosion free. The rest of the coach wiring will probably melt. Not sure why they did not use weather tight connections on many of these coach connections.

Jim_HiTek · 09-06-2021, 02:26 PM

Nice find and nice job. It'll outlast your ownership probably.

TT_Vert · 09-12-2021, 09:45 AM

Quote:

Originally Posted by Jim_HiTek

Nice find and nice job. It'll outlast your ownership probably.

There is no doubt it'll outlast the rest of the non OE ford wiring. I'm glad the circuit was as simple as it was. Originally I thought it went through the BCC as just around this time I had integrated a B.I.R.D that charges chassis batteries on shore power. The newer BCC's had that circuitry integrated but I had to add a secondary box. I thought that had something to do with it so I ended up wiring in diodes into the feeds to ensure there wasn't some weird backfeeding causing these issues. Also around this time I determined the chassis battery was dieing and when it died it caused some weird issues. (the step would not function, the mirrors and heater would not work and the jacks would not work. They were all on separate circuits but after a bunch of reverse engineering I determined that this all went through the BCC ignition circuit and when the battery was near dead it was causing these issues. So many little issues at once on a new to me RV when I've never had an RV made me feel some of the stuff I had done caused it. And without any schematics or wiring diagrams I had no idea for sure until I literally went through every circuit on every system on both the AC and DC sides. At least now I know this thing is (mostly) as good as new electrically.

Dave