1998 concorse melted 12 volt fuse in panel for overhead lights

[Flame]

Good morning everyone. Have not been on here in a while but have not had any problems until this past weekend.We went camping in a local state park and plugged in to their 30 amp hookup. Everything was working fine at home before we left. I plug in at the house to get my refrig/freezer pre froze before a trip. Several problems occurred during this 3 day trip. #1 (and the least of my worries) was the original round gold clock was stuck. The second hand was moving (in place) like it was stuck but trying to go. And of course that basically stopped the clock. I cannot see how to even get to the back of the clock or take it off the wall. #2 From the first day we hooked up it rained 12 straight hours. A total of 4 inches on my gauge over the 3 days. Now it was warm at first and I was running the overhead ac and all was fine for about the first 1-2 hours then discovered a steady drip of water right in the middle of the floor coming out of the very corner of one of the ac filter covers. At first I thought it was condensation not draining off somehow but later when the cold front blew in and ac not even running it kept dripping!! I removed the plastic rectangle cover and foam element from the filter cover area and looked up in there with a flashlight to discover a steady drip of water coming in from what "looks like" a ac mounting bolt. I have not gotton on the roof yet to see where it might be coming in. Oddly it rained the second day also but quit dripping.!!?? So why did it quit dripping?? Anyway...now my biggest problem #3. First sign of electrical trouble was on BOTH sides the amber colored strip lights above the windows the toggle switch had to be manipulated to "catch just right to make the lights "stay" on. Seems like I had this problem before so thought it to be no big deal and just figured the switches are old and should probably be replaced.That first night while sleeping we left the bathroom light on kind of as a night light but when I got up in the middle of the night I realized the light was out and I could smell what smelled like burned wires!! I ammediatly reached up to turn on a flourecent light above the couch and realized it did not work! Basically its easier to tell you what still worked and all seemed to be 110 volt stuff. Ac/heat work,refrig /freezer work/all the overhead lights ONLY DOWN THE MIDDLE work. Microwave works. Now I checked my fuse/breaker box and saw NO breakers thrown but...#1 fuse marked OVERHEAD LIGHTS was not just blown but It burned at the circuit board and actually melted the solder there!!! Apparently that is where the smell was coming from. All the stuff that seems to work "only on 12 volt" was shorted out!! All the flourecent lights all around except down the middle,bathroom light and fan,porch and door handle light,patio light all are out. What the hell happened!! I pulled the 15 amp burned up fuse but have no idea where to start looking for the problem and I damn sure don't want to get electrocuted. Please please help!! We love our LAND SHARK but don't want to be afraid to sleep in her!! Also, ALL 110 receptical inside and outside the coach DO WORK.

[SMan]

A slight twist (to the left as I remember) will remove the clock from the wall. Sounds like a battery change is needed.

I suspect possibly a re-bedding of the A/C unit may be needed. Also I recently replaced my A/C shroud that was badly cracked. You may want to assure yours is intact. That water intrusion could be the source of the electrical issue. That said a fuse should have blown not melted. I am not familiar with the florescent lights as I have the lesser equipped Premier with filament type fixtures.

Hopefully some of our more electrically inclined members will chime in.

Good luck.

[BobW9]

Hi, Flame. My Concourse is all pulled apart right now so I can't double-check, but I think the overhead lights down the center are on a separate 12v fuse than the lights along the sides. The bathroom fan, porch light, etc, are all probably on that same fuse labelled 'ceiling lights' in the Concourse manual, so it is not surprising they are out now.

I'm assuming the TV, VCP/VCR, furnace, detector panel on the range hood, and water pump all still work? They are all on separate circuits with separate 12v fuses.

My guess is that the fuse / fuse holder was bad, corroded in some fashion (or just not making good contact). The corrosion increases the resistance at that point, which increases the heat, so that point gets hotter and hotter. Because it is heat that is the issue, not super-high current, it doesn't blow the fuse, but melts everything instead when it gets hot enough.

As to why it happened that night - well, how often do you leave the bathroom light on all night? That is a good long time for that fuse to slowly heat up to the point of melting. And I bet that light is incandescent (mine is), so even though it is small it pulls a current.

1) I would replace the fuse board.

Or maybe now is a good time to just upgrade to a new replacement Parallax (or whatever) converter/charger if you haven't already. Though replace with an entirely new box, don't just upgrade the charger unless you are also replacing the fuse board on the converter.

2) All wires need to be disconnected from the fuses and carefully checked for signs of heat, discoloration, or corrosion.

If you find any on a wire, cut the wire back a few inches to where it looks better (probably as soon as it is inside its insulation sleeve), and then re-attach it.

3) Replace all the old fuses.

If they've been in there for years (like mine had been in for probably 17 years, since they all looked original to me), who knows the condition they are in now. Do not replace the fuse board and then keep the same old fuses!

4) I'd replace those switches, to be safe.

The fuse area also probably had something to do with the switches that had to be in just the right position to stay on - they could have needed the best contact-point on the switch to be able to overcome the voltage losses due to the fuse issue. Note that I think those switches for the amber window lights are at the end of each wire run from the fuse. These wires from each side of the coach get merged together somewhere just before the single fuse they share. It's possible that being at the end of each wire, with the longest run, and being incandescent (at least mine are) and drawing more current than the fluorescent lights under the cabinets, was part of the issue you were seeing with the switches (they made that fuse area heat up more and had trouble getting enough voltage). Especially possible since you were having the same problem with both switches (the odds of both going bad at the same time seems low).

If you're going to look for where the wires from the 2 sides merge before the fuse, good luck. In my case, it was inside a nest of protective tubing and reams of electrical tape where they came together - I had to pull everything apart recently, as I wanted to re-use a yellow wire that came from the TV area but didn't seem to go to the yellow wire I was seeing near the fuse area, and found it had been cut by someone and folded back and hidden inside that rat's nest... so I had a wire coming out of the rat's nest that was cut where I couldn't see it, and the one coming from the front stopped inside that same nest a few inches from the one coming out! Nice, eh?

It is possible the water issue was also a factor, but given that the wiring in question runs inside the bottom of the cabinets and eventually connects to the wall, I think it unlikely the water got to it. Unless there is any water down the inside of the wall of the cabinets (the outer side, where the cabinet doors are)? From there is could easily go along the inside bottom to the wiring. But it is unlikely that would be an issue in the future, anyway, since the melting was around the fuse.

No matter what, its not the end of the world Though it might take a trip or two after its fixed to feel totally relaxed again.

Good luck,
Bob

P.S. It would make reading your posts easier if you used paragraphs

[caconcourse]

We had a leak from our Air Conditioner in a heavy rain once, and just needed to tighten down the three bolts holding the AC to cinch down on the gasket. Either the bolts work loose over time, or more likely, the foam gasket deteriorates some, and just needs more squeeze to seal.

Ditto on the clock, needs a new battery most likely. Remove by rotating the clock about 30 degrees counter clockwise and it will pop out.

I would guess that melted fuse is water related, caused by a short or partial short as it got wet. It sounds like the non-working lights are on the #1 circuit (overhead lights) with the melted fuse. The water could be from the AC leak. You could also check the overhead cabinet under the TV antenna mount for moisture, indicating a leak in the antenna prtrusion. Also check the bathroom light fixture for moisture near the wiring. Since the cabinet lights were flaky, it is likely they were in the circuit that was compromised. The circuit may start working again after it dries out, so it may be a one-off event caused by the leak. If not, you will have to track down the short and fix it. It sounds like the #1 circuit on the fuse card is probably damaged beyond repair with the solder lifting. You can troubleshoot by moving the wire from the #1 terminal to the #2 temporarily. A lot of 12V wiring passes through the "hump" in the ceiling above the rear door. You can remove the curved hump panel to get access if needed for troubleshooting.

Actually the first thing I would try is the remove the melted fuse and use a voltmeter to check for 12V on the top half of the fuse holder. If it is present, the fuse card is probably still working. If so, I would put a new fuse in #1 after things dry out, to see if the lights start working again or if the fuse heats up or blows, indicating the short is still present.

If you still have the original Magnatek (Parallax) charger/converter, this would be a good time to replace it along with a new fuse board. There are several references to the this project on the forum.

[Flame]

Thank you everyone! I donate to this forum because you guys are great!! I just got down from removing the ac cover and I did clean out a bird nest and a couple of dirt dobber nest that possibly could have been routing the rain water wrong or at least causing it to fill up in places it shouldn't. I am going down to buy a good tube of silicone also after I attempt to tighten the mounting bolts a little. I see the actuall bolt where the water was dripping in around when I was looking from the inside. They are real long. Maybe 5-6 inch long. Looks like I tighten them from the inside. To answer an earlier question...yes my tv,water pump panel switches,vent hood fan and light DO ALL WORK. I will fix the clock battery now and after working on water leak I will start working on that fuse board. Is everything I am going to be doing on the fuse board going to be ONLY 12 volt as long as I am not plugged in outside to a 110 receptacle. Just don't want to get the crap knocked out of me. I'm thinking IF the one fuse connector is burned too bad couldn't I wire a separate fuse holder and bypass the board just for that one circuit??

[BobW9]

Flame,

1) For the bolt, I would advise pulling it all the way out, wrapping some Buytl tape around the threads near the bolt head, and then putting it back in and tightening it up. Doesn't need a lot, just a tiny piece stretched all the way around the bolt. When it is pushed back in, the buytl should squish around the hole and a little ooze out the top around the bolt head. Tighten the bolt inside snug. Wait a few hours or even days, then tighten further. You can't tighten all the way in one go because the buytl needs time to fully ooze around. It will resist too much tightening the first time, and needs that second time to get really water-tight. You can then put Dicor Sealant caulking on top of the bolt head and around it as a first water barrier.

Rather than silicone, I would use Dicor Self-Leveling Sealant (or ProFlexRV, another brand) - the one made for on the roof (not on a side, where this type would drip downwards), it slowly spreads out a bit and oozes into cracks. If there is already silicone there, then you need to look online for how to fully remove the old silicone, as almost nothing sticks to it at that point, including new silicone (meaning you might not get a long-term water-tight seal.

2) Given the age of everything, I would assume that what happened to one fuse on that board could happen to another fuse on that same board. Especially given that you said it looked like it burned at the board (not in the middle of a bad fuse). Up to you how to fix it, but with electricity and corrosion and fuses, I am all about caution. You could pull everything apart, give it a good scrubbing with a small wire brush to get every spot of metal shiny new, and reconnect it all. But do ALL of the wires, and every bit of metal you can reach on the board. And still buy new fuses - they are cheap and it doesn't hurt.

If you do take things apart, I recommend lots of photos from your phone before and during - makes it lots easier to figure out where everything goes when putting it back together! Don't forget (I still do sometimes and curse myself for an idiot each time).

Yes, we are talking only about the 12v side. But that does connect to the battery via the LVD, so, at the very least, make sure the main house switch in the cab is turned off. I might even go as far as to disconnect the positive cable(s) from the battery to be safer. If you have an inverter, I would definitely disconnect at the battery, because the inverter's wiring won't go through the LVD (you shouldn't be touching around an inverter's wiring for the fuses, but especially if you are checking all the fuses and wires, it is better to have nothing live in that whole area). Make sure you are not plugged in via the shore cable, that the generator is off, and that the engine is not running. Oh, and take off any jewelry on either hand or wrist (I once saw a tech get a nasty burn around his wedding band when he accidentally touched wires the wrong way near the batteries). As you get experience, all of these precautions might not be needed, though I tend towards paranoid after seeing that tech's hand get burned in front of me.

[chin_k]

Ditto on the silicone. Try to use something better like butyl and Dicor, as Bob suggested. If Blue is around, he would have come screaming mad

I have a spare fuse panel, if you want it, you can have it. Instead of doing a stand-alone wire with a in-line fuse, it is a better alternative. If you want to use this as an opportunity to replace the charger, then it is the time. If you are OK with the old Parallex, then I can send the fuse panel to you.

More importantly, I think you should fix the leak, and then find out why the circuit melted. My guess is that the wiring got loose over the years, and with just the bathroom light on, it was getting enough heat with arcing but not enough current to blow the fuse. If that is the case, then there should be still connectivity to the lights from the wire terminal at the fuse board. At minimum, after everything is dried out, and you tested for any damage wiring, you should torque all the screws on all the connection on the fuse board to make sure. The wires are stranded, so it is better than solid wire in vibrating environment, but ideally, I would put a ferrule on them if I am using it on a space shuttle.

If you use your bathroom light as a night light, you may want to upgrade it to LED. They do draw a bit of current, so I would only keep them on during the entire night if I am hooked up to shore power. It does get really hot after a few minute (original incandescent that is), so it probably will cause the lamp cover to get yellow and brittle if I do that too often.

[Scott]

I would replace the air con roof gasket. Not a terrible job if you and a partner are comfortable lifting 100lbs, and you don't mind being 9 feet off the ground. If you decide to replace it, check to make sure the roof is flat/level. My roof was a bit concave, and the air con gasket was foam and quite terrible. In my case, tightening the three screws wouldn't have done jack.

The incandescent bulbs originally in my Chinook drew 17 watts each. Which is actually a ton. A three foot strip of LEDs draws about 3.5 watts by comparison and produces much more light. Our bathroom nightlight is very low draw; it's motion sensitive and AA battery powered (but could easily be solar powered with the light coming through the vent).

[Flame]

I wrote a lengthy update a little while ago but maybe I failed to hit "submit". I do that sometimes! Anyway, good news. Clock works great with new battery. I tightenend and silicone my ac unit after cleaning birds nest and dirt dauber nests out. Removed all the galvanized shroud up top and got right to the bolts. Also caulked inside on bolts too. Now for the electrical...A new fuse in the fuseboard and everything came back on!!! I put ALL new fuses on the board. Still had a little trouble manipulating the toggle switches on the amber window lights so I removed them and cleaned all terminals and switches seem to work fine now!! I have found NO burned or darkened wires anywhere. I guess I will quit using my bathroom light for a night lite. What do ya'll think??

[chin_k]

Flame, since there are solder damage to the fuse panel, I would be very careful with continue to use it. Make sure you check it and there is no compromise. I also would check the screws to make sure they are tight, and there is no oxidation on the wire (it will turn greenish) that lead to extra heat.

Both the bathroom light and the string lights are quite power hungry, and heats up really well. You may want to look into red or amber LED for nightlight that plug into the 12 V socket by the sink, or on top of the sofa. Alternatively, change them to LED that does not heat up too much.