Wierd electric system problem October 29, 2015, 09:56:37 am Yahoo Message Number: 156730I had a strange problem after dry camping for five days at Capitol Reef NP. We had dumped, hitched the toad and turned on the ignition. There was a brief alarm squeal in conjunction with the ignition. I don't know what made the alarm. We went on down the road and stopped at a pull off for one more sight seeing walk around. Another brief alarm squeal with turning off the ignition and turning it on. Too brief to pin down. The engine seemed normal so we drove on. Stopped for lunch a couple of hours later and discovered nothing in the "house" part worked. No read out panel, no fridge no lights, no co detector. The engine worked fine and I checked the inverter for flipped breakers. None tripped. We were out in the middle of beautiful no where, so we drove on to Blanding, Utah, our destination. I was thinking maybe the inverter suddenly failed. So, we pulled into an RV park and I tried to make a call to LD, but got a busy, and then I looked at the fridge and the light was back on, everything was on. So I didn't call. Everything has continued to work but I've heard that brief alarm squeal once or twice when turning off the ignition. any suggestion as to what might be going on would be appreciated.The LD is a 2001 MB so she's got some age. We had just come from the LD factory where we'd had maintenance and replacement of vents and shrouds and roof resealing. Also replacement of exterior lights.Bonnie Jacobs From Bernalillo NM 2001 MB
Re: Wierd electric system problem Reply #1 – October 29, 2015, 10:53:16 am Yahoo Message Number: 156732Bonnie,It sounds like your house batteries are mostly dead. The propane detector will squeal as it complains about the transition through a low voltage while the truck alternator picks up the 12v electrical house load. It's a wild guess on my part, but it's time to pick up the meter and check voltages in the battery compartment.If nothing else, take a look at the LED status light. I bet it is OFF and not the usual green.Alex Rutchka, SE #4 '05 MB
Re: Wierd electric system problem Reply #2 – October 29, 2015, 11:14:42 am Yahoo Message Number: 156733Bonnie, I should have added it could be the battery is disconnected from the "house". Do you have a battery disconnect switch in the battery compartment? Also, there is a circuit breaker in the the battery compartment that if tripped has the same effect. However, if that breaker is tripped, I would worry about the why?Alex
Re: Wierd electric system problem Reply #3 – October 29, 2015, 01:26:04 pm Yahoo Message Number: 156735Bonnie,Your problem is similar to one I had recently. I'm with Alex on his suggestion that maybe the battery disconnect is suspect.On a trip out west a few weeks ago, I was not having any problems with my coach battery charging system, but after dry camping for a few days, though my voltage wasn't particularly low, I expected after a three hour drive, coincidentallyto Capitol Reef NP, that the batteries would have been fully charged again. To my surprise, the voltage was lower than when I began my drive (below 12 vdc) and seemed to be dropping. Attempts to isolate an unusual draw on the batteries didn't help, the refrigerator was the only thing using any power.I went to the battery compartment with a voltage monitor plugged into one of the house 12 vdc outlets hanging out the window so I could see it.I checked the tightness of the battery connections, which all were fine.I switched the battery disconnect switch OFF, and then back ON, and to my surprise my voltage monitor then showed 12.8 vdc, and the monitor on the range hood was back up to "Full" where it had been down to 1/3. I tried to tinker with the disconnect switch to see if it would drop the voltage as it had, but I couldn't reproduce it. I checked the truck charging system to the batteries with the disconnect OFF, and it was fine. I've since driven home and had no further problem. I've worked on electrical components for many, many years, and my battery disconnect switch seems "squishy" to me, that is, not a positive feel when changing from Open to Closed position or Closed to Open.I don't know if this is normal, but I doubt it. Apparently, in my case anyway, driving down good roads was causing the switch to move or maybe jiggle enough to not be making a good connection to the house distribution system. A new one is on order!Maybe this will help. Good luck!Bill2003 - 23' FL
Re: Wierd electric system problem Reply #4 – October 29, 2015, 02:26:07 pm Yahoo Message Number: 156736Bill, what kind of a battery disconnect did you order?Chris
Re: Wierd electric system problem Reply #5 – October 29, 2015, 04:29:51 pm Yahoo Message Number: 156737...do you mind sharing what brand or kind of switch you ordered? Thanks, Vaughn
Re: Wierd electric system problem Reply #6 – October 30, 2015, 09:06:24 am Yahoo Message Number: 156740I didn't order the switch yet. I forgot I put it in my Wish List on Amazon waiting for something else I need to get me over $35.00 for free shipping. ;-)I'm sort of glad I didn't order it now since I'm wondering if I may get some good (and welcome) advice about a good or bad experience with a particular switch. The switch I choose was the Marinco 701 Battery Disconnect Switch.It seems to be heavy duty enough for the task, and appears to be adaptable, making it somewhat easier to make the cable connections.Bill
Re: Wierd electric system problem Reply #7 – October 30, 2015, 01:23:36 pm Yahoo Message Number: 156742Bonnie,I agree that the squeal is probably coming from the CO detector and is due to the house battery voltage dropping too low.I had a similar problem in my 2003 26.5. The house power would drop, or shut off randomly, and the detector would squeal. Usually at 2 or 3 in the morning. I traced it to the fuse block PC Board in the house distribution panel. The input terminal blocks attached to the board with rivets. Over the years, corrosion built up between the board and the terminal blocks, causing a poor connection. Wiggling the battery wires (that clamped in to these blocks) would restore the connection, and the lights would come back on. You can see the blocks I'm talking about in this picture. The big red/white/black wires clamp into them.https://coachnetblog.files.wordpress.com/2015/02/dc-distribution-panel.pngMy fix for the problem was to remove the terminal blocks from the board. I cleaned up the corroded solder on the board, and reattached the blocks to the board with bolts and nuts. I then soldered the blocks directly to the PCB. Very solid connection now. No problems since.Russ
Re: Wierd electric system problem Reply #8 – October 30, 2015, 01:48:14 pm Yahoo Message Number: 156743"and the detector would squeal. Usually at 2 or 3 in the morning. "This squeal happened to my CO2 detector also in the middle of the night, but wouldn't go away till I removed the battery from it. That was not a good night. A new detector was needed to fix the problem. Now I can sleep in peace.bobmoore14Pahrump, NV. for a few...
Re: Wierd electric system problem Reply #9 – October 30, 2015, 03:22:19 pm Yahoo Message Number: 156744List me as one that had the same issue that turned out to be a low battery issue. No issues once I replaced the batteries. John 07 MidBath
Re: Wierd electric system problem Reply #10 – October 30, 2015, 08:15:18 pm Yahoo Message Number: 156748Thanks Alex and Bill. I think you have the answer. I know the battery was way down and I think it just hadn't had time to charge up. Though it seems like a couple of hours of driving would have charged it. I am on my way home, Lexington, KY, and will look at it and test it when I get there. Right now I'm spending a cold rainy night at a great little park in Kansas. Altamont City Lake, run by the town and only $10. Electric, sewer, water and free wifi.Bonnie Jacobs 2001 MB: Zoe
Re: Wierd electric system problem Reply #11 – October 31, 2015, 08:46:01 pm Yahoo Message Number: 156764Russ, thanks for the distribution panel pics and suggestion. There is no corrosion visible on mine but I will start testing connections and looking closer when I get home, which with luck will be tomorrow. So far it's been a slow trip. There is an enormous storm system in the middle of the country and it seems to be traveling east at exactly the same pace I am....lots of rain, bad visibility all the way through Kansas and Missouri.Bonnie 2001 MB, Zoe
Re: Wierd electric system problem Reply #12 – October 31, 2015, 09:51:52 pm Yahoo Message Number: 156766If you activate the battery disconnect switch you can remove those cables and smear dielectric grease on them. Then replace, turn battery switch back on and enjoy no corrosion. Napa also sells that red stuff that you spray on battery terminals. Seems to work.bobmoore14 HRCFP
Re: Wierd electric system problem Reply #13 – November 02, 2015, 11:27:34 am Yahoo Message Number: 156789Bonnie,No problem. FYI, the corrosion wasn't visible from the front side of the board on mine. It was only visible after removing the terminal blocks completely from the board. If you can wiggle the terminal block by hand with respect to the board, and it moves, it's probably not making a very good connection.I forgot to add another telltale symptom of a poor block-board connection. There will be discoloration of the pcboard where the block is riveted to it. You can even see it in the picture I linked earlier, where the ground (black and white) wires are connected. The block has loosened over time, creating a high resistance connection. Pass a lot of current through this connection (fan blower, water pump, etc.), and bad things happen. The junction warms up like a little heater and starts burning up the board, turning it brown. Mine was very dark, and very loose.I'm not a fan of attaching terminal blocks to pcboards with rivets... Regards, Russ
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Topic: Wierd electric system problem (Read 27 times)
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