ALT CHARGE LIGHT (While Towing)

[gprince]

I've read all the treads about alternator issues and their fixes, but mine is a little different. My ALT CHARGE light came on at the end of our first trip within 50 miles from home of a 600 mile trip. When I saw the light come on, I stopped at a truck stop and did some tests with my meter. I was putting out 13.9 volts at the batteries. I turned off the coach and turned it back on and the light went out. Thinking it was a fluke, I got back on the interstate and withing a couple of miles the light came back on. In my research, I have found that the light only comes on when I'm towing my toad. I cannot trigger the light sitting still, the light triggers after I tow more than a mile. I'm using the Cool Tech integrated wiring harness that plugs into my 08' Jeep Wrangler along with their negative battery post disconnect and pulling the IOD (Ign Off Draw) fuse in the Jeep's fuse box.

Any help would be appreciated.

[wa8yxm]

The idiot light comes on when the alternator output voltage is less than the battery voltage (it is a bit more complex than that) but that should be the only condition that turns on that light.. I'm guessing you have a problem somewhere in the wires, or the alternator is suffering from overheat and shutting down.. This could be caused by a diode failing in the heat.

However, just now we are dealing with a single (Well really 2) symptoms. and in another thread on a completly different topic I pointed out that is not enough for a diagnosis. As Johnny 5 says, Input, need more input. (Movie: Short Circuit)

[gprince]

Update: I received an email from the CoolTech company that sold me the integrated wire harness for the Jeep and they suggested I take a few measurements with my volt meter at the Jeep and coach. All my tests were good at the Jeep, but when I started testing the coach I found that I didn't have any voltage for the running lights at my plug-in at the rear of the coach and it suddenly dawned on me that I didn't have any running lights period on the coach. I have head lights, dash lights, turn signals, but no running lights. I even have over head lights in the cockpit when I twist my head light switch, but no running lights. I pulled the Monaco manual and looked up my fuse panels which led me outside under the drivers side compartment. I checked fuse # 34 in the Front Distribution Panel (the big one with three wing nuts holding the cover on) and the 7.5 amp fuse was good. I then checked Monaco 1 (under the big fuse box) and the Marker lights - 20 A checked good on continuity, so I moved on to the relays and pulled the marker lights. From the diagram on the relay, the continuity checked out, but I'm not sure I did it correctly given the connecting dots reference on the relay, but when I check continuity touched the pins where the connecting dots were connecting, I got a beep on my meter indicating good throughput. I then noticed that the left turn and right turn relays were the same brand, number, etc as the relay for the marker lights, so I swapped the right turn with the marker lights and went inside the coach and first tested the right turn signal and it worked, so I then did a drum roll like Chevy did on Christmas Vacation and pulled the headlight switch, ran outside and no running "marker" lights. Any suggestions on what to do or test next?

BTW, I keep on asking myself why I didn't know my "marker" lights were not working and I keep coming up with I guess I've been driving the coach in the daytime since my trip when the ALT CHARGE light came on and took it for granted that since the headlights and driving lights were on, the running, "marker" lights were on. Goes to show you, you have to check things closely!

[TEDDE]

I remember the course I took for my air brakes. To pass the questions I had everything down pat as to the sequance and the checks to make before driving. During that inspection a driver would have picked up any problems with the lighting system that may be present.

Today I forgot that sequance and what to even check for ..We get in... check the fuel gauge...check to see if the DW is present and off we go..I am sure more than one of us would have missed the running light thing...I know I would of....I guess I better brush up on my before travel ..coach check list..

I think we all get complacent after awhile..LOL

Ted