Electrical Troubleshooting - 2007 Monaco Executive

[ZackMan]

Greetings all,

I’m having an air horns issue on our coach which are located on the passenger side in the generator bay up front. This coach does not have street horns.

The issue first surfaced five years ago and I reached out to the consultants on irv2.com. I ended up replacing the airhorn solenoid and the uncontrolled blowing stopped. Afterwards, they would intermittently sound off but would stop once I disconnected the electrics. Once reconnected there were no further instances.

Recently the issue resurfaced; therefore, I checked the clock spring for continuity and resistance and the results were okay.

I contacted Vehicle Improvement Products (VIP) and spoke with one of its technical experts and conducted troubleshooting on the VIP SM211 Controller and the conclusion was that it was functioning properly.

The attached pictures (not the best in terms of clarity) shows the VIP SM211 Controller and PCB #8 in the front run bay underneath the operator’s seat. At the top of the PCB is a lit yellow signal LED about midway on the board (D11) that stays on constantly. When I disconnected the J2 on the Controller, the LED went out. Also when I removed the J2 connector on the board (far right), it went out as well. The two are tied together via the wiring schematic for the board.

I conducted a continuity test using the black wire up top on the J2 connector and the Controller J2-3 pin and it tested okay

I’ve said a lot and please excuse the long post. I may have missed something here and I need my air horns. Why is the D11 lit all the time? I’m sure, based on the little testing I have done so far, that the culprit is associated with this LED.

Thanks for reading and any feedback is surely welcome.

[Arby49]

Want to follow this as I am having horn issues as well.

[K7JV]

I've attached a schematic that probably accurately describes your system. On board #8, pin #1 of the connector provides a ground for the relay coil to cause the horn to operate. Pin #2 of that connector supplies +12V to the air solenoid when called for.

Only two things could go wrong on board #8, really, to cause the horn to honk when not desired. One, the relay contact could be bad, allowing an intermittent closure, but I think that is pretty unlikely. Or two, a ground could be inadvertently being applied to the line to pin #1. I believe that two of the associated LED's should only illuminate when the "Test" bus is energized. The third one associated with the horn should only illuminate when a ground is present on pin #1. If that LED, D11, is illuminated, then the horn is being called for. That LED is not capable of causing your problem, just showing that you have the problem.

The ground line appears to go directly from pin #1 (8-J2-1) to pin #6 on a connector M22 that I believe to be in your front run box, as well. From the other side of M22-6, it should go directly to the terminal on your Smartwheel controller unit. If LED #11 is lit, try separating M22 and see if it goes dark. If it does, your problem is toward the Smartwheel controller. If it does not, you may have an insulation problem on that 14GA black wire running between board #8 and M22. If it does go dark, try re-connecting M22, and pull connector P2 from the Smartwheel module. If LED goes dark then, check for an inadvertent ground on that wire from M22 to P2. If it does not, the problem is back to either the Smartwheel controller or the multiplex circuit to the Smartwheel, itself, which I think unlikely, since the other functions that share that multiplex path are functioning properly. Then the last possibility could be the horn contact itself, on the steering wheel.

Don't discount the possibility of insulation damage. When our coach was only 6 months old, my horn started honking, intermittently, on its own. I won't detail how I stumbled onto the problem by accident, but the problem was with the bundle of wires coming into the left (front) wall of the front run box. The loom was laying against the screw lugs on the top left part of the back wall. The left most of those lugs is for the headlight power. That lug was touching the wire loom, and with vibration from driving, it gradually "ate" its way thru the insulation on the wire, and would intermittently supply +12volt to the wire that goes from board #8 to the big loom plug and to the horn solenoid, itself. So the horn solenoid was getting energized without any help from the Smartwheel, or board #8, or anything else but the wire to the horn relay, itself.

Please let us know how you make out, and good luck to you. We managed to tick off a number of folks, over a few days, before we finally found the problem.

[hypoxia]

Originally Posted by K7JV

I've attached a schematic that probably accurately describes your system.

Cannot see it but would like to.

Not much help but I can confirm D11 is not normally illuminated on my coach.

[K7JV]

Dang! I'm not sure why it didn't work, but here's a re-try.

[ZackMan]

Originally Posted by K7JV

I've attached a schematic that probably accurately describes your system. On board #8, pin #1 of the connector provides a ground for the relay coil to cause the horn to operate. Pin #2 of that connector supplies +12V to the air solenoid when called for.

Only two things could go wrong on board #8, really, to cause the horn to honk when not desired. One, the relay contact could be bad, allowing an intermittent closure, but I think that is pretty unlikely. Or two, a ground could be inadvertently being applied to the line to pin #1. I believe that two of the associated LED's should only illuminate when the "Test" bus is energized. The third one associated with the horn should only illuminate when a ground is present on pin #1. If that LED, D11, is illuminated, then the horn is being called for. That LED is not capable of causing your problem, just showing that you have the problem.

The ground line appears to go directly from pin #1 (8-J2-1) to pin #6 on a connector M22 that I believe to be in your front run box, as well. From the other side of M22-6, it should go directly to the terminal on your Smartwheel controller unit. If LED #11 is lit, try separating M22 and see if it goes dark. If it does, your problem is toward the Smartwheel controller. If it does not, you may have an insulation problem on that 14GA black wire running between board #8 and M22. If it does go dark, try re-connecting M22, and pull connector P2 from the Smartwheel module. If LED goes dark then, check for an inadvertent ground on that wire from M22 to P2. If it does not, the problem is back to either the Smartwheel controller or the multiplex circuit to the Smartwheel, itself, which I think unlikely, since the other functions that share that multiplex path are functioning properly. Then the last possibility could be the horn contact itself, on the steering wheel.

Don't discount the possibility of insulation damage. When our coach was only 6 months old, my horn started honking, intermittently, on its own. I won't detail how I stumbled onto the problem by accident, but the problem was with the bundle of wires coming into the left (front) wall of the front run box. The loom was laying against the screw lugs on the top left part of the back wall. The left most of those lugs is for the headlight power. That lug was touching the wire loom, and with vibration from driving, it gradually "ate" its way thru the insulation on the wire, and would intermittently supply +12volt to the wire that goes from board #8 to the big loom plug and to the horn solenoid, itself. So the horn solenoid was getting energized without any help from the Smartwheel, or board #8, or anything else but the wire to the horn relay, itself.

Please let us know how you make out, and good luck to you. We managed to tick off a number of folks, over a few days, before we finally found the problem.

K7JV,

Thanks for your detailed response. The connector, M22-6, you referenced is what I looked at during my troubleshooting but not to the specific parameters you described. The attached air horn schematic depicts the same wiring flow but references M122-3. The third pin on the M122 is what I used to conduct a continuity test with Board 8-J2-2.

I noticed that the horn fuse on Board 8 (Air Horn Schematic) is a 10 amp instead of a 7.5 amp that is inserted on the board in our coach.

I will continue the troubleshooting and will apprise the forum once I am able to find something out. I really want to put this behind me.

By the way, will it be necessary to remove several boards to trace the 14 gauge black wire? I am thinking yes.

[K7JV]

You should be able to unplug M22 and then pull the wire from pin #1 on board #8. You could then just check the end of that lead you pulled from board #8 first for voltage to ground, and then voltage to +12V, just to be sure the cable isn't energized from an in-between contact. You should see essentially zero volts to ground as well as to +12V. Then, check the same with your ohm-meter to ground to check for the short circuit that could be causing your problem. Hopefully there will not be a standing ground on that wire. If there is, you've found your problem, and a new wire run between those two points might be in order, if you don't start pulling circuit boards. I wouldn't want to do that. They've really got those in there to stay!!

That way you wouldn't have to pull any boards to check out the wire. If it tests good, you should be good, at least as far as that exposure is concerned.

[ZackMan]

Originally Posted by K7JV

You should be able to unplug M22 and then pull the wire from pin #1 on board #8. You could then just check the end of that lead you pulled from board #8 first for voltage to ground, and then voltage to +12V, just to be sure the cable isn't energized from an in-between contact. You should see essentially zero volts to ground as well as to +12V. Then, check the same with your ohm-meter to ground to check for the short circuit that could be causing your problem. Hopefully there will not be a standing ground on that wire. If there is, you've found your problem, and a new wire run between those two points might be in order, if you don't start pulling circuit boards. I wouldn't want to do that. They've really got those in there to stay!!

That way you wouldn't have to pull any boards to check out the wire. If it tests good, you should be good, at least as far as that exposure is concerned.

Latest Update.

I tested the 14 gauge black wire inserted in the M122 pin 3 connector (J2) on the SM211 Controller and Board #8, pin1 on the J2 connector and found voltage to ground and a high resistance for ohms.

I replaced the 14 gauge black wire but had to remove Boards 8 and 11. The wires were bundled tightly and I removed several cable ties to access the wire and thread it through to separate it. After cutting both ends, I soldered In a new piece that was heat shrunk over both solders. I then replaced the two boards, reconnected the wires and reinserted into the connectors that were plugged into the SM211 and Board #8.

The D11 yellow LED was still lit initially until I removed the J2 connector from the SM211 and once I reconnected it, the yellow LED stayed unlit.

Once I started the coach and had enough air to push the horn pad, the air horns sounded and would not stop. At this point I unplugged the J2 connector and the horns stopped. Once I replugged the horns did not sound again.

I decided to call VIP again and explain my delemma and the consultant I spoke to previously remembered our first conversation. I explained everything I did the last few hours.

He asked me to blow the air horns using the push pad and then remove J1 from the Controller. He said that they should stop if I do. If not, there is something wrong with the SM211. Of course, the air horns kept blasting when I removed the J1 connector.

I ordered a new SM211 based on VIP. Once it arrives and is installed I will provide another update.

[ZackMan]

UPDATE!! UPDATE!!

I ordered, received and installed a VIP SM211 Controller, Revision C that replaced the original SM211 that was in the front run bay.

This installation corrected the issue of the air horns blowing uncontrolled. Based on my most recent consultation with VIP, my particular issue has now been resolved.

Thanks to all for your feedback. It was truly appreciated.

[hypoxia]

Good to hear Zackman.

I just replaced my VIP SM 211 which cured my intermittant cruise control and windshield wiper problems.

[ZackMan]

Originally Posted by hypoxia

Good to hear Zackman.

I just replaced my VIP SM 211 which cured my intermittant cruise control and windshield wiper problems.

hypoxia,

It seems that the SM211 goes south in time. Glad to hear that your two issues were resolved with the installation of a SM211 replacement.

[Arby49]

Is there anything special needed to change the SM211? I am changing mine so thought I would take the 12v system down and take a cable off the house battery.

[K7JV]

You really should be able to just unplug the connectors from the module and then "remove and replace", then re-connect. Make a note of which went where, to be sure you go back the way it was.

[Arby49]

Originally Posted by Arby49

Is there anything special needed to change the SM211? I am changing mine so thought I would take the 12v system down and take a cable off the house battery.

Thanks for the help. Plan to do just that right after a scrumptious lunch prepared by my DW!