I have no lights on the warning light panel at the top of the gauge panel. Lifted the dash. There is just a plug in harness at the rear of this panel. How does this system work?
John,
Welcome to the Forum! Always happy to see new GV owners join the group. Feel free to ask any questions. We will try to answer.
As to your warning light problem. Do you have any wiring diagrams for your coach? If so, is there is one labeled (bottom right corner) B-2037 12V Wiring Diagram? If not, I will link one below that should be close enough to work for your U300.
First question: When you turn the ignition key ON does anything on the dash "come alive"? Does the blower motor on the dash heater work? Does the radio work? If YES, you can move on to next step. If NO, then you possibly have a bad ignition solenoid. We can fix that.
Looking on the wiring diagram, as you have observed, all the warning lights are served by one plug. The plug supplies power plus all the sensor inputs. The power comes from a fuse which is contained in the big fuse block, under the lift-up dash cover.
There should be a fuse diagram pasted to the underside of the dash cover. If not, you can located the fuse using the wiring diagram. It is labeled WARN LTS GAUGES 10 - a 10 amp fuse.
First check the fuse - see if it is blown. If it is good, try unplugging the harness connector and then plugging it back in. Check for loose wires in the connector.
Let us know what you find.
https://www.foreforums.com/index.php?action=media;sa=media;in=3856
https://www.foreforums.com/index.php?action=media;sa=media;in=3857
Thanks for the info. This is my first motor home. I'm pretty handy with repairs as I've owned an auto restoration shop for over 20 years. The two manuals I got when I purchased the MH are not very complete. No wiring diagrams or operating manuals. When I turn the ignition switch on. The only light that lights up on the warning light panel is the parking brake light. And it is very dim. No turn signal indicators or high beam indicator, etc. I really appreciate your help. Will check the things you mentioned. Did I mention that all of the regular gauges and their lights work fine. It's just the warning light panel.
OK, just checked the fuse. The fuse is good. Unplugged the the rear of the panel. Nothing changed. The only light that lites up is the parking brake light.
All those lights have a common ground. See if you can find the ground wire and check if it is good.
Check these links out - see what you can find info/diagrams pertaining to your coach.
https://www.foreforums.com/index.php?action=media;sa=album;in=165
https://www.foreforums.com/index.php?action=media;sa=album;in=194
John, welcome to the group. We also have a 1993 U300. When I turn on the key I get warning lights, the gauges come alive, and I get an annoying screech/whistle sound. If the only thing you are getting is a dim parking brake light I'd check the ground wire, as was mentioned above, but also check whether you are getting +12vdc there. Start with the start batteries in the engine compartment. Connections clean and tight? What voltage do you see?
Does the Detroit start?
Thanks for the advice. My internet has been down for a couple days, but here is what I've found. Checked and grounds are good. With the key on I've got 12volts to the back of the warning light panel. But no lights. All other gauges lights etc work. The engine starts fine. Now when I bring 12 volts directly to the high beam indicator light, and the turn signal indicator lights they light up. But the harness that plugs into the back of the warning light panel is all white wires, and they run down to what looks like some sort of module. There are colored wires that plug into that module. With voltage at that plug. But nothing coming out of the module. The module looks like it might have some sort of buzzer mechanism on it. Does this control the warning lights?
John,
That thingy is called the Javelina Digitron Alarm Module.
I hope it has not totally failed, because AFAIK they are pretty much unobtainable. The only possible hope of finding a replacement would be from a salvage yard or somebody parting out a coach.
See if the diagram below (from our Forum library Schematics folder) is any help:
https://www.foreforums.com/index.php?action=media;sa=media;in=4510
I had dealings with that device early in our coach ownership days. In my case the warning squawker wouldn't shut up. I have no idea why, but squawker finally went silent after I had our Allison ECU rebuilt.
Annunciator Trouble (https://www.foreforums.com/index.php?topic=22425)
Found a photo of it in a old post, but that doesn't help you any:
Wiring diagram (https://www.foreforums.com/index.php?topic=40466.msg401701#msg401701)
Thanks for the wiring diagram. It gives me a place to start. It looks like some of the warning lights work when they get a 12 volt signal. Turn indicators, high beam, etc. but it's looking like the others might work off of the warning switch grounding. If this module just controls the warning buzzer. I can probably find a work around. If it actually controls the warning light panel then I might be in trouble.
John,
If you keep poking around it may take you back to the ignition switch or the connector. Stranger things have happened with the switch going bad.
Mike
Once you have the 12V schematic for the U300 electrical system in hand, take it to the print shop and have it blown up to as large as they can and store it in a mailing tube. You wouldn't look a a house plan in 8x11 size so blow the much more complex 12V schematic up. Bill Chaplin (RIP) showed up at our house with a big schematic. I think of him every time I pull it out.
A bad ground is the first suspect when you have a dim bulb. Check the ignition solenoid under the dash top first for secure wires and the ground located nearby. Vibration is always a reason to check connections on a coach or any vehicle.
Pierce
Update on my warning light panel and buzzer. It was the connector at the alarm module. Some time in the past someone got in there and loosened some of the wires going into the connector. Thanks for all of the advice. I'm brand new to owning and working on motor homes. But I've got about 40 years of restoring and customizing antique autos. It's really great to have a group of people that have so much experience and info on this subject. I'm just getting started on this project. So, I'm sure I'll have a million more questions. Again thanks to all for the info.