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I live in my RV fulltime, but I still work fulltime. Consequently, the RV stays parked most of the time. Knowing that this isn't healthy for it, so I start it up weekly, along with the generator. I also try to drive it once a month to keep the transmission and tires happy. The previous time I started the engine, it cranked a little slow but fired up after a couple of seconds. Didn't worry too much about it as it was cold outside (40ºF). I've only had this since last August, so I didn't have any prior experience starting a V-10 in anything but very warm weather. I had to fly out of town for my job, so the RV didn't get started for 2 weeks. When I returned, I tried to do the weekly ritual of running the motor and generator. The dash lights were VERY dim, and the engine didn't even begin to roll over. I pushed & held the auxiliary start button on the dash, but it had no effect. I took my Digital Volt Meter (DVM) and found that the chassis battery was at 6.7 VDC, but the house batteries were at 13.5+ VDC. The converter was working, but the chassis battery wasn't being charged. I opened the Battery Control Center (BCC) and found that a large solenoid is used to connect the two battery systems together to charge both sets or use the house batteries to assist in starting when the chassis battery is dead. Since I'm always plugged into shore power, and the converter is charging the house batteries, the solenoid had to be the culprit. I took my DVM and found that the solenoid was receiving 13+ VDC to engage, but I measured different voltages on the two buss bars it connects to. With some research online, and some previous experience shopping at a local marine supply center, I bought a replacement solenoid for $36. Below are a serious of photos and a description of the job. Only a few tools were needed, and some basic DC electronics experience. This isn't a detailed guide to show you how to do the job, just an idea of what it entails. All the usual disclaimers apply, attempt at your own risk! |
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Click on any image for a larger view. |
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The Battery Control Center (BCC) is located under the hood, on the driver's side. Access is partially blocked. Lift the two levers, and gently pull the cover towards you. |
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This is what you'll see. Make sure you disconnect shore power, the chassis battery, and house batteries. You don't want to go digging into this box with power still going into it. |
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Same view, slightly different angle. If you look in the top left corner in the box, you can see a silver solenoid. This is the battery charging/auxiliary start solenoid. Mine was getting 12V signal voltage to engage the solenoid, but the internal contacts were shot. |
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I unplugged all the wire harnesses, but not
the individual wires. The harnesses have plugs that are keyed, and
are all different from one another. In other words, you can't hook
them up incorrectly later.
There are about 4 screws holding the circuit board in place, and 2 nuts from one threaded post must also be removed. The board can then be gently pushed to one side, though some wires are still attached. I removed the two bolts holding the solenoid to the back of the box, the disconnected the signal wires, and finally the nut on the top and bottom of its posts. Since the solenoid's posts are inserted through a buss bar at the top and bottom, you can't pull it out. I disconnected a battery terminal on the side of the box, and removed that bolt. This allowed the lower buss bar to be pushed down, freeing the solenoid. BE CAREFUL! There is a black plastic insert and washer that are used to isolate the bolt used for the battery terminal. on the side of the box. When the bolt is removed, one washer will fall inside the box, the other will fall outside. Took me 5 minutes of careful searching with a flashlight to finally find the outside washer. |
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I bought a replacement solenoid, made by Cole
Hersee. It's a continuous duty model rated at 85 Amps. The
Bounder Forum reported that it is a directly replacement part per the
BCC manufacturer.
Note: Electrically, it's a good replacement. Physically, it "almost is". While the electrical contacts are perfect, the mounting plate on the back does not line up with the holes in the back of the box used by the original. The solenoid has 5/16" studs on the top and bottom which insert through the buss bars. The mounting plate on the back of the solenoid rests firmly up against the back of the box. Even without the two mounting bolts, the solenoid is firmly in place, and can't move. I didn't bother drilling new holes for the bolts. Your choice. Please see links below for the replacement parts. |
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Here's the part number to make sure you get the correct replacement. Beware, this company also makes a solenoid of the same physical size, but it isn't a continuous duty rated model. |
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The new solenoid installed, and circuit board re-installed. |
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This is the schematic on the back of the BCC cover. I left the image fairly large to have enough resolution to clearly read it. |
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I took a pair of large diagonal cutters and peeled the lip of the cap up so I could examine the bad solenoid. The buss bars from the chassis battery, and house batteries connect to the big terminals on the left and right sides. The two smaller ones on the top connect to the signal voltage and this pulls the piston down. When the piston is pulled, a large washer contacts both of the terminals. After repeated usage, the contact get pitted and develop carbon deposits. It doesn't take much to render it useless. |
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Here's the piston removed so you can see
the underside of the contact washer.
This could easily cleaned and rebuilt. But at $36 for a replacement, and 2 hours worth of labor, it isn't worth the minimal cost savings to risk having it fail again in a year or two. Once metal is pitted, it's never the same again, even if the surface is filed clean. If you do insist on keeping it as a spare, the washer can be turned over, and so can the terminals. |
| Once the solenoid was replaced, I put the
BCC back together. Before applying power to the box again, I did a
full inspection of my work to make sure nothing was improperly
connected. I then reconnected all the batteries, followed by shore
power. I could hear the propane alarm from inside the coaching
whining. I did a reset, and it was happy.
It took a couple of minutes for the timing circuit to engage the
solenoid. Before it did, I pushed the Auxiliary Start Switch on
the dash, and I could hear the solenoid engaging. Once the timing
circuit automatically engaged the solenoid, the voltage on both
buss bars settled to around 13.5 VDC. Problem solved. Cost:
$36, 2 hours, a few scraped knuckles, 1 bottle of Stewart's Orange Soda,
and about a dozen cuss words. If you find that your circuit board is fried on a 1990 1/2 ~ 1996 model, you can buy a new replacement from Bud Weisbrod. He said the boards should be around $135 if he can get another shipment. Contact him for more details. Bud is a regular contributor on the Bounder Forum. |
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Last updated 02/27/22 All rights reserved. |
