2004 Classic - Furnace fuse pops

[Brawny]

Hi Folks,

I'm looking for some troubleshooting advice, to try and figure out what's wrong with our furnace. Rather than just take this to our dealer, I'd like to do a bit more investigation first, in case its something relatively simple, or at least to be able to narrow it down so that I have a better idea of what's required to repair it, even if I can't do it myself.

For background, we were away at a WBCCI Rally a few weeks back, and our furnace wouldn't come on. I found that the 7.5A fuse was blown, and was able to replace it, thanks to a fellow AS owner who happened to have one. (Yes, I'll be adding those to my stock of spare parts very shortly ). Tried the furnace a second time, and the replacement fuse blew.

I opened up the external furnace cover, and pulled back the black plastic cover, and didn't see anything obvious (no burnt wires, etc), but wasn't sure what I should be looking for. I didn't have my voltmeter with me at the time, so couldn't start poking around.

I'm hoping some of the handier folks on this forum will be able to share their advice on troubleshooting steps.

We're planning on a 'last minute' adventure later this week, where we'll be away for 2 weeks with our AS, and while we'll be OK without the furnace at night as long as we have 110VAC to run a space heater, I'm not keen to head out without the furnace working, just in case.

Thanks for any and all advice!
Steve

[Brawny]

This is so unlike Airforums! No advice after two days? I guess I should have mentioned tow vehicles or tires or self defence in the thread title...

I guess we'll plan on using a small space heater if it gets cold out, and have the dealer look at it before we store Wanda for the winter. We're headed to a WBCCI Rendezvous at the end of September - I expect I'll get lots of troubleshooting advice there!

Cheers,
Brawny

[Pride&Joy]

Sorry I don't have any advice but wanted you to have a reply! We have a 2001 Limited that we have owned since July. We are camping this week and it will be chilly so will be trying the heat pump for the 1st time and taking a space heater for back up. We are total newbies and hoping no blown fuses.
Hope all is well with your furnace!

[ROBERT CROSS]

Is this your unit?.....

Never blew a fuse, but it would't start....cleaned all spade connectors & bingo.

Bob

[CBWELL]

Check to make sure that the motor/fan turns. If seized, that will blow the fuze. You might have a fan problem with insects/ bugs.

[Brawny]

Originally Posted by ROBERT CROSS

Is this your unit?.....

Never blew a fuse, but it would't start....cleaned all spade connectors & bingo.

Bob

Hi Bob - it is.

Sorry for not closing the thread off - I resolved the issue a while back.

It looks like somehow a 7.5A fuse got put in place of the 10A fuse that is normally used for the furnace. I don't know how it happened, but I can say that the furnace worked last year, and Wanda was at the dealer for some repair work this year, and then the furnace started popping fuses...

When it stopped working, I didn't question the current rating on the fuse - just replaced it with another 7.5A. After trying this a couple times, I decided to go through the manual. I couldn't find any references to 7.5A fuses. Also saw the startup current on the furnace motor was ~9A, so definitely 7.5A wasn't sufficient...

The 7.5A and 10A fuses are both red coloured. Possibly someone changed the fuse and didn't look too closely at the number and just grabbed a red fuse. Not sure why anyone would have been mucking with the fuses in the first place, but whatever...

Good advise to clean the connectors. We're getting close to putting Wanda to bed for the winter - I'll clean out the furnace compartment with compressed air, and clean the spades before then.

Thanks for the advice!
Steve

[ROBERT CROSS]

Another no heat tip....

Mud daubers in the furnace exhaust tube.....line the door with a heavy duty furnace filter.
I buy bulk at HD and cut to size. Goes on the fridge and water heater door also.

Bob