[xGE_97]

Ok. Quite an experience. 3 special tools and about 12 hours labor ( not counting making/purchasing tools). I guess its bad gas pump ettiquite to do this at the pump. After freeing the door, I'll have to tape it shut for travel. Probably that green painting tape. We are in the Lincoln/Omaha area at Pine Grove RV Park while checking out the area for a Teton Club International rally for fall 2026. After this we will probably stop in Kansas City for the same purpose. Then its on to Newell for replacement latches. When I get a few weeks in one place I'll design a replacement striker bracket. This will be removable with a 1/4" drive set without the contortions. Yes, its work but 2 failures will have to happen to cause the work.

For now, a wrap up:

Picture #1 shows the latch removed from the door.  When mounted on the door, the left side of it is facing the bottom, the label side faces the door edge, and the side with the jaw faces toward the bay and captures the strike. The latch refuses to release the striker. The release arm is internally detached from the release mechanism. At some point I will open one of these latches. Maybe its rebuildable hahahaha.

Picture #2 shows some special tools. The striker is about 18" above the bottom of the coach, therefore any wrenches to reach it need to be longer. In this case, a ratchet and a combination wrench. I cut the wrench in half and epoxied the halves into a piece of conduit. I also used the conduit to extend the handle length of a 1/4" 120 tooth ratchet. The long screwdrivers were part of the thought that I could jam the striker bolts with enough force to hold the bolt steady and allow the nylock nut to be wrenched off. NO. The long vice grip was a just in case I need another option. Besides its too cool to pass by. At the bottom is a piece of 3/4" flat stock. I bored a hole in the end, pounded a 3/16" hex key into it and had it tack welded. I trimmed the hex key length to 3/16" in length because it needed to insert into the stryker bolt but the striker was in the latch jaw, so it had to be short. This required a couple of trims by the dremel. The weld snapped when I used it to take off the stryker on the other side. This side had released, I was just to lazy to get another key. I'll have to fix the weld.

Picture #3 shows a close up of the broken striker bolt key tool. The key is still stuck in the bolt.

Picture #4 shows the special hex key tool inserted into the striker bolt and a jam screwdriver to the left of it. Had the tool slipped out, I would have had to position it over the bolt keyway and then rotate the nut to re-engage. Therfore the first disengagement motivates you to use force!

Picture #5 shows the latch moments after the striker was detached from the bay wall bracket. The latch us still savoring the striker. You can see the tapered bolt head just above my thumb. The special key tool needed to insert into the striker bolt, yet be able to do this from the space between the body of the latch and that bolt. ( the space is just above my thumb).

Lots of challenges, and man....those gas struts are no joke.

Creslie suggested taping the door shut. I don't like tape on old paint edges. I'll try rope and see. I'll add more when I see how effective rope is and anything more on the latch or striker bracket.

[xGE_97]

One additional thought on the latches here since so much time has been spent on the mechanical aspects.

The use of a current limiting strategy would prevent burn out of the solenoid, should the power be on the latch for more than a short time. This scenario could be holding the latch to compensate for weakened struts or a short in the wiring, or, like in my case, a bay handle that did not drop back into position when released. it stuck open and although I pushed it down, it stayed active within the bay door.

Additionally, a "one shot" type of circuit should be used to limit the time that the pulse can be on. 

A reverse-biased diode should also be placed across the latch solenoid to quench the voltage spike caused when the EM field collapses as the power to the solenoid is removed.

[Jack Houpe]

Great pictures and explanation, thank you for sharing with everyone for the future. I like the kiss factor "Keep It Simple Stupid" sometimes things that make our lives easier in the end make them more difficult. Do you think the solenoid is fried due to power being applied to long?

[Richard]

Bravo !!!!!!

Thank you for taking the time during a very stressful event to post the process. You are among brothers when it comes to field engineering. I know that I “enjoyed” the event vicariously.

[xGE_97]

Yes, the handle on the bay door stuck in the pulled open position when I went to fill up a day or so after leaving Newell. On this type of bay door the handle is really just used to activate the electric latch. There is no mechanical connection to the latches. I was warned by Kris Jones to just use it like its a button, and don't hold on to it. The solenoid will burn out, he said. This handle was never stiff before. I used dry lube spray to loosen it. i also pushed the bay door lock button (which removes the power from the bay doors) to no avail.....the solenods were dead.

Just glad that I can "enjoy" this part of it by recollection, and with a bourbon. Next comes further enjoyment when I get to Newell. All it takes is money....

[[email protected]]

Thanks for the update Bob! Glad it’s done sorry you had to suffer through it, but we did learn some new tricks and looked like you used quite a few to get it done. I for one would love to see the autopsy of the offending latch to know why it failed both electrically and mechanically. You would think that the latch would have some sort of limit on how long the coil is energized, mechanical limit switch that opens the circuit once the latch opens and closes possibly. Enjoy your bourbon, it’s well deserved!

[Jack Houpe]

I'm with Jeff I'd love to see the mechanism that failed and it's back up cable that didn't work. Has Newell used a different latch on later models?

[xGE_97]

Guys!!
Its almost 10 PM here in Greenwood, Ne. Dottie and I just got back from a full day of scouting rally activities, I've had some nice bourbon and I'm coming down for nighty-night time. I've never stayed more than a day or two in Nebraska before, but I like it. Lots of rally stuff to do and a few really nice campgeounds. Anyway today was making up for lost scouting time due to the latch issue (I must be relaxing because its a past "issue" now.....kinda sounds reasonable).

I will definitely autopsy the latch and put pictures and color commentary here in this thread. Good to keep it all together. So tomorrow is my last day here and then we move on to Nebraska City, then Kansas City for a few days before getting back to Newell. All that rambling means it'll be a few days before its posted, but as I say.... have Dremel, will travel.

Southco doesn't make the latch ( EM-03-43-340) anymore. They make another one that looks similar except that it has a release cable, not a release rod. Newell has to modify the cable to attach a cable extender when they install it. There may be some electrical wiring difference as well because they rewire the bay door if they use this new latch.

The latch doesn't protect itself. I think Southco probably figures that anyone using rhe latch would figure that part out. Newell is a small shop, quantity-wise so the latch issue probably isn't on their radar. I'll make some suggestions to them, but who knows what'll happen. I'll add onto this post with my changes....when they happen. So I'm on the road until October and then I have International travel planned for a month, so.....it may be a bit before I have a design that is worth publishing. But I'll be hanging around.......

[xGE_97]

The Southco autopsy photos. View at your discretion. Yes......the guts are hanging out.

So, as a refresher, This latch failed when I opened the fuel door and the handle remained "pulled out". I ran to shut off the bay door power, but didn't get there fast enough. I then spent time spraying that door handle until it worked freely.
Subsequently, the mechanical release mechanism failed on this latch. The mechanical release on the other latch still worked.

Image #1 shows the latch with its cover removed. The latch has 3 main areas. The left portion is the mechanical latch with release capability and microswitch (more on this later) The center portion is the linear gear mechanism. The right portion is the motor portion. In this image, the release arm is clearly disconnected from its linkage to the latch. The latch linkage is a "U" shaped slot in the mechanical release lever of the latch. The microswitch on the latch is maintained  active when the latch is open. It has NO and NC wires available external to the whole assembly. The center linear gear mechanism is stuck in the half activated position. When the latch assembly is not energized, the spring would normally push the gear mechanism such that it would move all the way right, spinning the motor in reverse, in the process. The motor is coupled to the linear gear by a "bow tie" shaped coupling. The motor itself appears unremarkable in this photo, except that the rightmost margin area appears sooty and the adjacent nylon appears burned. 
Normally at rest while latched, the release arm is located in the slot of the latch release lever, the linear gear body is pushed all the way to the right, and the motor is at rest with no impressed voltage. When the latch is activated into the electrical release case,  a short 12VDC pulse is placed on the latch. This causes the motor to spin, moving the gear to the left, impacting the release lever, thereby causing the lever to rotate open and force the strike from its jaw. When the latch is activated into the mechanical release case, the gear and motor are irrelevant because the release arm pulls directly on the release lever, thereby directly causing the latch to open. Upon opening the latch assembly, the release arm was decoupled from the release lever, eliminating that method of release. The motor had also failed, eliminating any hope of that function.

Image #2 shows a closer view of the release arm and the slot in the release lever. It appears that the release arm is quite a bit thinner than the width of the release arm slot. It also appears that there is sufficient space between the top of the release lever slot and the adjacent wall of the latch assembly. This was probably the way that the release arm became uncoupled.

Image #3 shows the seized motor and the gear/spring not being able to push back.

Image #4 shows the melted right side of the motor. The rotor shaft uses the plastic housing as a bearing. Once gone, the motor does not move.

Image #5 shows the paddle/ "bowtie" used to couple the motor to the linear gear.

Image #6 shows the rating plate. Clearly, this device needs some sort of management of the voltage applied to it. It cannot be just connected to the bay handle switch. A quick flick of the handle will probably cause at least a quarter second of voltage to be applied. That is 5 times rating. This is why I say some sort of "one shot" circuit needs to be used. A "one shot" is used to control the length of the pulse applied, as well as to control the time to re-trigger. Additionally, the striker should be able to be removed directly from the bottom of a wedged-open bay door. In this way the latch would not be over stressed, electrically, and a way to overcome complete failure would be achieved. The microswitch is not rated, which means its not going to withstand use at a 5 amp rating, as the motor draws. If it was capable, the microswitch could have been used to cut off power while the latch was open.

[Richard]

Great Work!

Thank you so much for the detailed analysis, and I can’t wait to see the solution.

On top of that, I personally want to thank you for contributing. The core of forum is 20 years in the making, and we have a great deal of expertise and documentation on the 2004 and earlier coaches. This forum really needs individuals like you with later era rigs to contribute to help each other and future owners. The forum just doesn’t have the data base on the newer rigs. Slowly but surely, you and others are building that base.