Dead Coach

wmurdock · 12-14-2011, 04:34 PM

Just looking for suggestions, while I found some related items so far I have had no luck. I have a 2005 Alpine Coach (bought new) and it currently won't start and has no power at all to the front of the coach (lights, ignition, stereo, step, etc.) I have replaced the coach batteries (they were due) and the solenoid (hoping for a simple fix) to no effect. Based on some of the threads my next thought was the Vanso system. On the back 2820 I get a power on light and several of the leds come when I turn on the battery disconnect, however at the front 2820 I get no lights not even a power light, there is power to both pins on the two pin power supply but no lights come up on the unit at all. This seems to indicate that it may be a problem with that 2820. The Vansco suggestion is to swap one for the other to try to determine if that is the issue but since WRV mounted the front unit with bolts and loose nuts on the opposite side of the front bulkhead (that I can't get to since with no power the gen slide won't extend) There is another controller above the front 2820 (I think its called the power distributin module) and there are two "on" lights on it that both are on steady. The RV has not been in use for a couple of months and worked fine when I parked it last. Any help or insight any of you could give me would be greatly appreciated. Also any recommendations on any mobile RV mechanics that are knowledgeable on Alpine's might be of use if I can't get this figured out (I'm in the Mukilteo area)

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wmurdock · 12-14-2011, 06:24 PM

Update, did more forum reading and found a thread from "Cookiejar" in 2009 where he had a similar problem and found that he had low voltage to pin #26 on the VMM. I found the same issue and attached separate power to pin #26 and the VMM powered up, unfortunately I still have issues. With separate power to the VMM (original wire not connected) I get engine start and Dash/Headlights, unfortunately I also get a constant air horn as soon as the air pressure comes up. If I also tie the original wire back into the mix the horn stops going off but nothing else changes. In both cases there is no power to the Gauges themselves, warning light indicator, radio, rear camera, step cover or step - I hate electrical issues !! I will try to trace down wher the factory power wire comes from to see what the issue is

EngineerMike · 12-14-2011, 09:05 PM

The problem might be w/the PDM power unit above the front 2820. IIRC there are two main power lights and a series of other LEDs:
Inputs 1-6= Ignition/Accessory
Inputs 7-12= Battery Enable
I'm going from memory here so good luck: seems like all 12 were on when I turn the key to On or Run position (not Start per se), and only the upper 6 were lit w/key Off. Can anybody verify that?
If the PDM isn't sending correct 12V out to circuits of the VMM, there will be issues. If there is an internal problem on the PDM, the VMM won't drive proper operating outputs.

dgerstel · 12-15-2011, 09:29 AM

Did you check the chassis fuse/breaker in the battery compartment?

wmurdock · 12-15-2011, 01:58 PM

Mike

I am pretty sure that the only lights I have on the PDM are the two "On" lights and that none of the leds are on so that would make it seem like a potential problem area and perhaps why I am not getting full voltage to pin #26 on the VMM. I couldn't find any info on the PDM itself for trouble shooting but I plan on calling Vansco to get their thoughts

wmurdock · 12-15-2011, 02:02 PM

Dale

Yes, checked everything back at the batteries and seem to be getting full 12V everywhere including the "Hot" post under the VMM in front so I don't think it is a power issue, it's just not getting out to where it should go to up front

jrlandrum · 12-18-2011, 08:25 PM

I know this will sound crazy, but my ground wire behind the frame at the battery bank was loose. Caused me all kinds of problems and finally complete loss of power. robert

wmurdock · 12-19-2011, 12:30 AM

Robert, thanks for the idea. Are you talking about a point not in the box with the six wingnut holding the cover on it as I have examined all of them and all of mine are tight. Also all of my connections at the coach batteries are good as well as I just re-installed them

wmurdock · 12-19-2011, 01:07 AM

Also EngineerMike seems to have given me the "on" led's for the PDM but can anyone tell me which ones are on at the back and front VMM's with both of the disconnects turned on. While all of my my back VMM's leds flash "on" when I turn on the main disconnect after that I have only the "Power" led and led's at inputs 4 & 17 on it. The front VMM has no led's at all and the PDM just has the two "power" led's on for Buss bars 1 & 2 no "on" led's and no input or output led's. After jumping 12V power directly to pin#26 on the front VMM I get it's "power" & "net" leds along with led's at inputs 5 & 16 and outputs 7, 16 and 17 and on the PDM the led at output 11 comes on. This allows me to get the engine to start, run headlights and operate the gen slide. Thanks to this I was able to swap the two VMM's as Vansco suggests to test them which actually didn't enlighten me as both operate the same in either location so either they are both good or both bad. Also, EngineerMike, you seem to be saying the the PDM sends power to the VMM. Is that for sure because the guy I spoke with at Vansco pretty much said that they couldn't help me at all on the PDM (he didn't sound like he even knew anything about it) as all they did was supply the modules to WRV who then did their own configuration. It would be helpful if I knew which module comes first - PDM, Front VMM or Back VMM (chicken or egg) since I am pretty sure that I probably have one problem that is just cascading down the line getting worse as it goes but without a starting point I am simply lost. I have looked but I can't seem to find any information on how the WRV's multiplexing systems was set-up.

Wayne R · 12-19-2011, 11:45 AM

wmurdock,

I took some pictures of my VMM'S and PDM with ignition on and off. All systems on my coach work properly. Hope this helps.
Wayne

VMM ignition on

VMM ignition off

PDM ignition on

PDM ignition off

Rear VMM ignition off

Rear VMM ignition on

puttin · 12-19-2011, 12:02 PM

Just curious- what's a "2820"? I'm going 5150.

wmurdock · 12-19-2011, 01:50 PM

Wayne, WOW that looks like Christmas compared to mine. Obviously I am missing alot of my leds and your shots give me a much better idea of where I am at. Thank you very much for your help.

EngineerMike · 12-19-2011, 06:07 PM

Wayne- I see in your front VMM Ign ON photo the PDM Inputs Bar1 & Bar2 lit, and Outputs 13 & 14 lit. You photo for PDM Ign ON didn't post, can you put that one up?