Vansco 233660 Multiplex Module

[Tirebuster]

I have a 2006 Class A Alpine Coach. I need to replace or repair the 2 Vansco 233660 Multiplex Modules - 28 inputs & 20 outputs. Any ideas would be greatly appreciated.

[Kid Gloves]

First, you should know that the modules, VMM2820, are no longer being manufactured.
Second, repairs are typically unsuccessful.

On the positive side, a properly functioning unit from any 2005-2009 coach will work in your 2006.

Next, we’ll need some additional information from you in order to determine if one or both modules have actually failed. For starters: What is not functioning properly on the coach? How did you conclude that the problem(s) are caused by a faulty module? Have you tried resetting the units by turning the chassis battery disconnect to the off/open position for ~30 seconds and the back on?

Give us a little more information and we’ll do our best to get you up and running again.

[Tirebuster]

I took them out and switched the front to the back no change. Then i checked the j 1939 cable for resistance and 60ohms each end . Took the 2 mod out sent them to Radwell Int. for repair and they sent them back saying they were both bad and thats where i am right now. If anyone can tell me what to do next i would really appreciate it Thanks Tirebuster

[Ljwt330]

Originally Posted by Tirebuster

I took them out and switched the front to the back no change. Then i checked the j 1939 cable for resistance and 60ohms each end . Took the 2 mod out sent them to Radwell Int. for repair and they sent them back saying they were both bad and thats where i am right now. If anyone can tell me what to do next i would really appreciate it Thanks Tirebuster

First, I am not doubting your situation at all, but it is very unusual for both VMM units to "go bad" at the same time. In fact, I have never heard of it happening (which really doesn't mean much.) When a VMM goes bad, some things fail to function properly. Switching the front unit to the rear will determine if the problem follows the unit. If there is no change in the malfunction, the problem is more likely to be with a connection rather than both units being faulty. Not always, but more likely.



We really need you to answer all the questions posed by Kidgloves. We also need some history, such as, has any welding work been done on the coach or is there anything that could have "fried" the electronics? We also need to know if the malfunctions came with the coach (new ownership?) or just started. If they just began, what was the context of the discovery, including any work done just prior?


Sadly, if both units are bad, you just may be dead in the water unless you can find used, post-2005 units in a salvage yard. You need at least one good unit to program a new, blank unit which are no longer produced.


Things look bleak, but I am not certain that your diagnosis of two bad units is accurate, regardless of what the repair facility reported, because there is not much detail about the malfunctions and what you've tried to do to resolve the issue.

[whalepirot]

Originally Posted by Kid Gloves

What is not functioning properly on the coach? How did you conclude that the problem(s) are caused by a faulty module?
Give us a little more information and we’ll do our best to get you up and running again.

Ditto! The modules act as relays and circuit protection for many operations.

Do the units power up? If so, have you found and reviewed the sticker on the inside of the panel, frontal to the pax seat? It shows the inputs and outputs and activating, say the headlights, you should see two input LEDs (L and R) [I believe they're independent] LEDs light up, and the corresponding output LEDs light. If those flash, there's a fault. The Vanscos output either 12v or act as ground, depending on the circuit's needs.

All this means that a) many 'professionals have no clue about them and b) they can be a valuable troubleshooting tool.

Example: my dash A/C sucked. Moe than one A/C pro said it was likely a bad expansion valve, as I already knew it was not low on freon. The rear A/C gets a signal from the dash control head via the R VANSCO. I saw the correct input LED illuminate, but the output LED was flashing. That hinted why the A/C clutch was not engaging. A separate 12v jumper wire kicked the clutch on, so it was ok. Tracing the trigger wire back to the VANSCO, I found it crushed, hence shorting out, under the diesel's intake plumbing. Fixing that wire, cost me some time, but zero dollars, surely not $1500+ to a 'pro' for an unneeded repair.

I'm not a know-it-all, but there are many here who know far more about these coaches than outside shops. You seem capable enough with the simple tools and fixes that many of these coach's problems present. My learning curve has been steep and deep, but rewarding.

[Tirebuster]

I put the units back in the coach and as far as i can tell this is what doesn't work.The start side of ignition,rear turn signals, brake lights and tail lights.

[Tirebuster]

There has been no welding but i did change the house batteries. Then this started sorry for for taking so long to respond but Im having some health issues. I put the mods back in and as far as I can tell the start side of the ignition,the rear turn signals,brake lights and tail lights don't work. When the ignition is on the gauges keep cycling.

[Ljwt330]

Originally Posted by Tirebuster

There has been no welding but i did change the house batteries. Then this started sorry for for taking so long to respond but Im having some health issues. I put the mods back in and as far as I can tell the start side of the ignition,the rear turn signals,brake lights and tail lights don't work. When the ignition is on the gauges keep cycling.

Sorry to hear of your health issues, I hope things are better for you now

Still not convinced both vmm have gone south. I don’t know where the rear vmm is located on a 2006, but if it’s like mine it’s right there in the battery bay. The place where you were last working on the house batteries. Lots of fuses back there that could have been tripped, not to mention small wires and harness plugs. Your failed functions seem to be associated with the rear unit or wiring located in that area. There is also a module back there that controls data to the dash and gauges.

I still go back to the fact the problem did not follow the vmm when you switched front to rear. That tends to be a problem with the circuits/connections. Really unlikely both units failed at the same time after just being parked. If there were no sparks flying as you replaced the house batteries, nothing seems possible to cause failure of both vmm units.

Try contacting Engineer Mike, asking about how to diagnose the Vansco by reading the LEDs, and if all the malfunctions can have a common fail point like bad ground wire to the vmm or even the ecm.

[Jeep401]

"There is also a module back there that controls data to the dash and gauges."

Ljwt330,
I would be interested in this, how do I identify it, does it have some writing on it?
I get the gauge swiping test that op mentioned. sometimes while driving down the road. The dic says comm error when it happens. Possible starting point for me. 2005 36fdds.

[Ljwt330]

Originally Posted by Jeep401

"There is also a module back there that controls data to the dash and gauges."

Ljwt330,
I would be interested in this, how do I identify it, does it have some writing on it?
I get the gauge swiping test that op mentioned. sometimes while driving down the road. The dic says comm error when it happens. Possible starting point for me. 2005 36fdds.

I wish I could remember it's correct ID, I think it's VDM or VDC. Someone will post the correct term. It's the module that translate the chassis data so it can be read/displayed by the gauges.

On my coach, it's located on the same side bulkhead as the rear VMM, but closer to the inboard wall. It is a black, rectangular box with harnesses connected. From my understanding, it is not repairable or even available anymore. I had a sudden gauge failure while driving that set off the alarm. I shut down and restarted and all was good. As a precaution, I disconnected, cleaned, and reconnected both plugs into that module. No problems since, but that may be coincidence.

I don't know if this is it, but see the doc attached. It doesn't show it, but explains it and how to troubleshoot.

Annunciator & VDComputer Service Bulletin 97-04.pdf

Found a picture and a link to a thread about the VDC.



https://www.irv2.com/forums/f104/vdc...ed-534311.html

[Jeep401]

Originally Posted by Ljwt330

I wish I could remember it's correct ID, I think it's VDM or VDC. Someone will post the correct term. It's the module that translate the chassis data so it can be read/displayed by the gauges.

On my coach, it's located on the same side bulkhead as the rear VMM, but closer to the inboard wall. It is a black, rectangular box with harnesses connected. From my understanding, it is not repairable or even available anymore. I had a sudden gauge failure while driving that set off the alarm. I shut down and restarted and all was good. As a precaution, I disconnected, cleaned, and reconnected both plugs into that module. No problems since, but that may be coincidence.

I don't know if this is it, but see the doc attached. It doesn't show it, but explains it and how to troubleshoot.

Attachment 345169

Found a picture and a link to a thread about the VDC.



https://www.irv2.com/forums/f104/vdc...ed-534311.html

Thanks for the reply. I too only need to shut the coach off and let the warning lights power down and re- start. Everything functions as it should except for the gauges of course while this point s going on.
Odd thing for me, it only seams to happen when I'm in stop and go traffic. This very well could be related to the op's original post. This gives me a starting point to look
Thank you.

[whalepirot]

Originally Posted by Ljwt330

I disconnected, cleaned, and reconnected

A major key, IMO, to fixing 'new' vehicles. DeOxIt is my bestie for some time now and an early step in many repairs, given the low control voltages in most devices. Repairing appliances and my own cars for decades, I learned that, unlike many 'pros' approach to R&R some pricey module, a simple cleaning of the connectors AND grounds fixes most problems.

A Corvette I have was warning of many impending serious dooms. Cleaning grounds and in one case resoldering (foreign made) some surface mount components saved me thousand$.

'Weather pack' connectors can deteriorate and sallow moisture to corrode the contacts; the added resistance degrades the low voltage circuit, causing seeming component failure.

Check, clean, repair degraded connections and reboot the machine!

[whalepirot]

Originally Posted by Tirebuster

,the rear turn signals, brake lights and tail lights don't work. When the ignition is on the gauges keep cycling.

Here are two docs that may help. Deciphering the circuit takes some time, given the labeling and slight difficulty in directly viewing the sockets.

The first doc lists a F units inputs and outputs. You may find a sticker listing similar info for your coach (as my '07 does),pasted on the inside of the 'kick panel' (curved, under the dash, right side) listing same. This tells you to look and see a certain LED lit up, when you activate a circuit, i.e., r turn signal: #12 input, #9 output, referring to the attached document. NOTE: Your coach's sticker may show differences.

If you see #12 input illuminate, the circuit is okay to the unit. Output #9 should lite steady. No light may indicate a VMM failure; flashing points to a 'downstream' circuit AFTER the VMM; perhaps a shorted wire.

Similarly, the R unit helps find the problem with your turn lights and 0other aft items.

The 2nd doc (Parker), page 1, offers little, as it refers to components that no one has, AFAIK. Page two describes the above.

[Hayduke]

Originally Posted by Ljwt330

From my understanding, it is not repairable or even available anymore.