Lost all gauges and start button

thomasinnv · May 25, 2017, 10:36:21 AM

With master switch on you should have 24v on stud 14. From there it goes to start switch then back to stud 3 if you have anti-theft then to stud 4 (straight to stud 4 if no anti-theft) from the start switch. With the start switch held in you should have 24v on stud 4. The only place the start button and guages have in common is stud 14, which gets it's power from the master relay in the front junction box.

If you find no power on stud 14 look for a 30a circuit breaker on the main 24v bus bar, position 4.

Hope this helps narrow it down. I think I would start by looking at stud 14 for power if it were me.

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Scott & Heather · May 25, 2017, 11:30:46 AM

Much thanks. So, I have no idea what fixed it....but it's working again. Incidentally, for a while now I've heard a relay clicking on and off in the front JBOX. I narrowed it down to the relay for the bulb test switch. Somehow this switch is also tied into my atec touchpad so with it having issues my atec pad wasn't lighting up. To get the bus going I had to bypass the bulb test switch and connect the atec touchpad directly to power. Working perfect now, relay is disconnected so I have no test lights but whatever. Half of them have never worked anyway.

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Iceni John · May 25, 2017, 12:13:05 PM

Quote from: Scott & Heather on May 25, 2017, 11:30:46 AM
Much thanks. So, I have no idea what fixed it....but it's working again. Incidentally, for a while now I've heard a relay clicking on and off in the front JBOX. I narrowed it down to the relay for the bulb test switch. Somehow this switch is also tied into my atec touchpad so with it having issues my atec pad wasn't lighting up. To get the bus going I had to bypass the bulb test switch and connect the atec touchpad directly to power. Working perfect now, relay is disconnected so I have no test lights but whatever. Half of them have never worked anyway.

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Is it a relay or a self-resetting circuit breaker that's clicking? A while ago I inadvertently misconnected something in my junction box, and I heard a CB there clicking off and on - it puzzled me until I realized what I had done!

John

Scott & Heather · May 25, 2017, 12:27:06 PM

Yes John, thanks for the correction it was indeed the self resetting CB. I am not sure why it was doing that but the test switch had loose wires and I'm guessing something was shorting

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Aviator · May 25, 2017, 03:02:14 PM

I have a 102C3, and I've had this happen before

Look at the ground studs in the front electrical box on the bottom of the box. I had a stud that was corroded almost off and it would cause these odd intermittent electrical issues. I would loose things like the starter switch, electrical gauges, turn signals and it was kinda random.

Larry
MCI 102C3

Scott & Heather · May 25, 2017, 04:38:29 PM

Thanks Larry. I got the start switch working again but gauges are all still dead. Without a schematic, I'm shooting in the dark.

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gumpy · May 25, 2017, 04:54:33 PM

Quote from: Scott & Heather on May 25, 2017, 11:30:46 AM
... I've heard a relay clicking on and off in the front JBOX. I narrowed it down to the relay for the bulb test switch. Somehow this switch is also tied into my atec touchpad so with it having issues my atec pad wasn't lighting up. To get the bus going I had to bypass the bulb test switch and connect the atec touchpad directly to power.

As I said. You have a short that is blowing a circuit breaker. Find the short.

BTW, when you have a short that is blowing a circuit breaker, it's generally not a good idea to bypass the circuit breaker.

Scott & Heather · May 25, 2017, 07:21:42 PM

Craig, the short was in a different part of the circuit. I had to remove the wires going to the circuit breaker. I then merely connected my touchpad to power. Not sure where the short is in the bulb test circuit but I can't chase this down without my schematic manual. I'll be headed back to Michigan in three weeks and will get it and troubleshoot more then.

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Scott & Heather · May 28, 2017, 08:33:57 AM

Ok guys, I am banging my head on this dead gauge issue. Even my fuel gauge is dead. Again, my coach electrical schematic is in my storage trailer in Michigan, but I really would like to get my gauges back online before the trek from Texas to Michigan. My jbox panel diagram indicates "AA" for dash panel gauges. I can't find "AA" on the diagram anywhere. If someone here could post and wiring schematic for a 102C3 you would make my month. Seriously. Or find "AA" on this diagram. I can't see it anywhere.

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Lin · May 28, 2017, 09:05:10 AM

It would seem that the common power to the gauges is at fault. Could you use a tone generator at the gauges and trace it back to the panel?

Scott & Heather · May 28, 2017, 10:08:40 AM

That's exactly what I'm going to try to do right now. Thanks. It seems like WH 36 wire might be at fault but i have no idea where it goes.

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gumpy · May 28, 2017, 10:14:36 AM

Well, looks like it might be circuit breaker #3. 6A. You're diagram above indicate AA, but I don't even see that on the diagram. I suspect it's the upper right one next to the stud board which is labeled CC. Note that the one below it is also labeled CC.

The bus bar appears to be fed through stud 14. Comes through the 6A CB and goes to stud 26. This then feeds a common point for all gauges and TT lights, though that common point location is not shown. Feed from stud 26 wire number might be 3-RD-18.

B_K · May 28, 2017, 10:31:37 AM

Scott just a thought, but you were working in the engine compartment when all this started.
I would go back and double check ANY wires/plugs that go from the engine/transmission to the coach. Especially any that go to the electrical panel over the muffler where you removed the old air cleaner. You may have accidentally bumped one of the plugs or harnesses and not even realized it.
If it were me I'd actually disconnect each plug and spray them with some CRC electrical cleaner (or equivalent) and then put some dielectrical grease in them before reconnecting them.
Might not be the problem now, but good preventive maintenance that should be done periodically anyway!

BK

Scott & Heather · May 28, 2017, 10:38:01 AM

Thanks Craig....I'll use your numbers and continue chasing...

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Scott & Heather · May 28, 2017, 10:40:49 AM

Bryce, my fuel gauge is dead too...which tells me it's not in the engine compartment??? I have been unplugging every harness behind the dash and cleaning it and plugging it back in. I have two cans of CRC so I'm going crazy lol. The only thing I've messed with really is the stud that feeds the bulb test light. But nothing there seems to be connected to the gauge power as far as I can tell....if I had my manual with schematic I could methodically chase this down. I might end up just driving without volt and fuel gauges. My coolant temp gauge works fine. This is just weird

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