Community Forums

Bill767 · 12-12-2015, 03:17 PM

On the road now, will check the relay base again, thanks.

K7JV · 12-12-2015, 03:59 PM

Wow, Bill, this is getting challenging! If the front park lights are working, then you must have power at the lug in the FRB on what they call TS1. You also said that the 20 amp fuse in the RRB is good, and there is power to the relay K2 on board #8 in the RRB. For the tow lights to work, the 12 volt signal from the front of the coach is needed at the second terminal from the top of the plug on the left of K2 on board #8. That 12 volt signal energizes relay K2, which then passes the 12 volt supply from the 20 amp fuse to the tow plug.

I just went back to my RRB and learned this. There are two wires in the second terminal from the top on the connector beside K2. One of them goes behind and to the right of board #8 and appears to exit through the left of two 1" (or so) holes in the back wall of the RRB. The other goes behind, up and to the right, behind the top row of circuit boards, and I'm guessing exits through the right of the two 1" holes. One of these two wires might be the one from the FRB, and the other likely goes to a point where it then splits into three, to the two tail lights and to the license plate light. Unfortunately, I can't see where that split happens, nor can I see where those two wires go from when the leave the RRB.

Bill, I turned my park lights on and off, and that relay, K2, picked when I turned the lights on, and dropped out when I turned them off. You might try that. If that relay is picking when you turn on our lights, the line from TS1 in the FRB to the rear of the coach is good, and the problem is completely in the back of the rig. If it does not, the problem is between TS1 in the FRB and that plug on the side of board #8 in the RRB.

So, I would check and see if that relay is operating when you turn on your headlights or your park lights. Do let us know what you find. We're getting closer!

To test that circuit, I had a friend put a finger on the relay itself while I operated the light switch. He both felt and heard the relay click when it operated.

Bill767 · 12-13-2015, 04:42 AM

Will let you know in a couple of days after we get settled into our winter digs. Right now I am leaning towards that board #8 being bad.

K7JV · 12-13-2015, 07:01 AM

Very good, Bill, safe travels!

As for the board, there's nothing there but plugs and relays, with some traces on the back to make the connections. It's nothing more than an easy place to mount the relays and connect to them. There's really nothing to go wrong with them, other than physical breakage or a cold solder joint on a connection.

When you get settled, take your voltmeter and try these checks. You should have a lug in the left center of the RRB that will give you a good ground for the black lead. The readings you'll want will be taken by sticking the pointed red probe of your meter as deeply into the plug openings against the wires as you can, and I'm talking about the 5-pin plug to the left of the second relay from the bottom of board #8.

Top lug - This should be a white wire to that ground lug, and should show 0 volts with headlights on and off.

Second lug - This should give you 0 volts with the headlights off, and +12 volts with the headlights on. It is the terminal that is fed from TS1 in the FRB. On our coach, there are two wires in that terminal position. I'm guessing that one probably goes on to the coach tail and license plate lights, and the other probably comes from TS1.

Third lug - This should give you 0 volts with the headlights off, and +12 volts with the headlights on. It is the switched terminal that goes from the relay to the tow vehicle plug to light the tail lights on the tow.

Fourth lug - This terminal should be empty.

Bottom lug - This terminal should have +12 volts on it regardless of the headlight status. It is the terminal that is fed from the 20 amp fuse in the RRB.

Let us know how that works out for you. Again, safe travels!

Bill767 · 12-18-2015, 12:43 PM

I did the check you suggested today.
The second lug and third lug are reading zero volts headlights on or off. So I must not be getting power from the front run bay although I do have front parking lights. So I'm still at a loss.

K7JV · 12-18-2015, 03:29 PM

Bill, I'm running out of ideas. If you want to confirm that the wiring on the rear of the coach is ok, you could try jumping +12 volts to the second terminal on board #8 and see if the tail lights and the license plate lights operate. If you put +12 volts on that terminal and those lights light, and the really operates with a click, you've absolutely narrow the problem to the conductor between that point and TS-1 in the FRB.

The only additional information that I can find refers to two connectors, #113 and #35. Both of these are likely in the rear of the coach. The #35 connector has a feed from TS-1 for tail lights, and appears to be used by the back-up camera. If you can find that, and it has +12 volts with the lights on, you can tap that for the input on the second terminal of board #8. The #113 connector is likely to be at the rear of the coach, and it will be the end of the circuit from TS-1, and is the only wire on that connector #113 that is brown, according to my drawings. If you can find connector #113 somewhere at the rear of the coach, you should be able to verify the circuit from that connector to the J2 on board #8, as well as verify the existence of the +12 volts with the headlights on, from TS-1 in the FRB.

At this point, it's just trying to find the two ends of the circuit from TS-1 to R8-J2-4, which is terminal #4 (second from the top) on plug J2 on board #8 in the RRB.

Wow! What a problem!! If you want to email me you can, at K7JV@ARRL.NET. I can share what drawings I have from Monaco, if they will help any, much easier than I can reduce their size and attach them through iRV2's site.

K7JV · 01-08-2016, 06:49 AM

Bill, did you ever solve your problem with your lights?

Bill767 · 01-09-2016, 06:01 AM

No, not yet. I have made several runs at it myself and with the help of a knowledgable friend. I am going to get a circuit tracer and see if that might do the trick. It's taking awhile and since we are sitting for 4 months, a few other items have taken priority. I will report back what I find when I find it.