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FormerBoater · 05-16-2019, 12:51 PM

Just completed a 2600 mile round trip from NE Florida to Manchester NH.

Our active duty USMC Staff Sargent graduated on Saturday from SNHU , so we picked him up in Quantico and gave him a lift to the ceremony.

Great time, but here are the issues that arose during our 8 days on the road:

-Furnace #1 has excellent ignition of the burner, but their is no heat or air movement coming from the front of the coach heating vents.

-A/C #1 stopped working on the southern return portion of the trip. No response from the A/C unit or the rooftop fan. Suspect a 12 volt fuse but do not know in which fuse box location the fuse for the thermostat may be. (Did not test the heat function of the thermostat but will do tomorrow).

-Now for the weird one. Filled the fresh water tank in Northern Virginia before leaving the campground...all was normal and the tank filled completely. 10 miles down the road stopped for fuel. Water was pouring out of the coach from the wet bay. Leaked down to 1/2 tank by the time we arrived in northern SC. Water pump works normally and when hooked up to campground city water there are no leaks that I can see and we have water at all faucets, the toilet and the shower.

It is not a faulty check valve as I southern engineered a valve/fresh water hook-up a few years back when the factory check valve failed.

TIA for any and all input!

mackwrench · 05-16-2019, 07:04 PM

The furnace may have a blower motor failure or controller.
The motor is 12V do look for a fuse for it as well.
If by chance the controller is bad, Google Dinosaur Electronics....way less $$

Kinda odd the same furnace and A/C not working, perhaps a bad wall thermostat? (Just a wag)

The A/C is not 12V, the blower is 120 ac voltage. You can remove the top cover, check for power at blower, if the compressor is running, the breaker is good.

No idea on water leak, you can remove the wet Bay panel and perhaps see it....

FormerBoater · 05-17-2019, 06:09 AM

Mackwrench, do you know if the thermostat has its own 12 volt fuse and if so the location?

The A/C unit is not activating at all, no compressor or blower. The 120 volt breaker is not tripped, so I am hoping for a blown fuse for the thermostat itself.

Any tips on how to determine if the furnace problem is the blower motor vs. the controller board? I am hoping it is the controller board as I have purchased a board for the water heater from Dinosaur Electronics and am very pleased with the product and their tech support.

The fresh water tank problem seems to be from a rupture/crack above the 1/2 way full mark. I am surprised this happened at the end of the trip...the third leg thru NY City on the way up is where we experienced earthquake road conditions and there were no issues immediately following that punishment to the motorhome.

For anyone else planning a trip to the great NE this summer...avoid NYC and I-95 north of the NJ line!

FormerBoater · 05-20-2019, 07:25 AM

Well I guess I will re-phrase my questions as follows:

-Does anyone know the location of the 12 volt fuses on this vintage (98) American Coach for the furnaces and the thermostat?

Jon_C · 05-20-2019, 08:06 AM

I do know most furnaces have a safety device inside called a sail switch that makes sure the blower is on before ignition of the burner. The fan air pushes a metal “sail” that closes a switch to allow gas to flow. Can u hear the blower coming on at all? If not do not use that furnace and have it repaired. Burner with no air to cool it is not good.

And dometic thermostat does require 12v, mine is in coach 12v fuse box outside on drivers front bay not sure where yours would be. Its not labled but if i pull fuse 6 the thermostat is dead. See pic

mackwrench · 05-20-2019, 06:26 PM

Quote:

Originally Posted by FormerBoater

Well I guess I will re-phrase my questions as follows:

-Does anyone know the location of the 12 volt fuses on this vintage (98) American Coach for the furnaces and the thermostat?

Oops, sorry boater, I hadn't checked here in a few days....but on my 99 there is 12V fused at the dash panel ahead of steering wheel, another just next to the A/C power breaker box under foot of bed and one next to chassis/house batteries in the compartment just behind right side drive tire.
If you've had your coach a while you've seen all them by now lol

I'd suspect the furnace/t-stat fuse at the fuse box under foot of bed.

FormerBoater · 05-21-2019, 07:03 AM

Yep Mack, I am familiar with all the fuse locations, just have not done the deep dive to see if I have a fuse that is labeled thermostat or furnace.

I also have not attempted to fire up the furnace....been too hot here in NE Florida!!!!!

As the burner would ignite when we were up in New England, I am wondering if perhaps the duct work got jarred loose traveling through the roads that are worse than most 3rd world countries! The sail switch was definitely allowing the propane to flow to the burner and the ignition was normal.

Jon C, I can hear the blower running..just no flow thru the vents.

Still hoping it is just the thermostat for the A/C issue

mackwrench · 05-21-2019, 11:00 AM

Quote:

Originally Posted by FormerBoater

I also have not attempted to fire up the furnace....been too hot here in NE Florida!!!!!

You ain't telling me nothing, I promise it ain't no cooler in Tallahassee!
Forecast for 100 degrees in N. Florida this holiday weekend!

completelymo · 05-22-2019, 09:32 AM

Quote:

Originally Posted by mackwrench

Oops, sorry boater, I hadn't checked here in a few days....but on my 99 there is 12V fused at the dash panel ahead of steering wheel, another just next to the A/C power breaker box under foot of bed and one next to chassis/house batteries in the compartment just behind right side drive tire.
If you've had your coach a while you've seen all them by now lol

I'd suspect the furnace/t-stat fuse at the fuse box under foot of bed.

Same locations for my 1997 Eagle.

FormerBoater · 05-22-2019, 11:47 AM

Just did the "deep dive" on all the 12 volt fuse panels this morning.

Nothing is labeled thermostat and the 2 furnace 15 amp fuses look good.

There is a 2 amp bussman fuse in the thermostat itself that looks good, but I will replace it as I have been advised by Keith Mallory in the past that these fuses can go bad and still look pristine.

Fresh water tank is holding 3/4 of a tank of water with no leaks, however the tank will not pressurize and the water pump continues to run very slowly and quietly after you turn the faucet or shower off. Will look for a crack above the 3/4 fill line when the weather cools a bit.

Hopefully I can get to it and apply a little JB Weld magic!

FormerBoater · 07-11-2019, 02:29 PM

Just a concluding post to say that as of today all of these issues are in the rear view mirror.

Kept us off the road for almost 2 months!

Time to go camping!!!

Thanks for everyone's input of the various threads about each of these issues.

SlowJoe · 07-11-2019, 08:06 PM

Glad to hear it. Please post your findings so we can benefit from it if we have the same problem. Thanks!

FormerBoater · 07-12-2019, 06:36 AM

Quote:

Originally Posted by SlowJoe

Glad to hear it. Please post your findings so we can benefit from it if we have the same problem. Thanks!

A/C had to be replaced. After 21 years of service this was not a surprise.

Furnace had to be reconnected to the heating duct.

The fresh water tank did not have a leak. I over-filled it and started a siphoning process which solved itself once the water level was low enough to break the siphon.

The fresh water pump had to be replaced..once again after 21 years of service this was not a surprise.

Fresh water pump was leaking and that was why it was cycling ....JB Weld did not solve the problem!