Help with electrical glitch - Page 2 - Fiberglass RV
Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 05-09-2019, 07:31 AM   #21
Senior Member
 
ZachO's Avatar
 
Name: Z
Trailer: Sasquatch
Montana
Posts: 2,561
By “disconnect the leads” do you mean where the furnace is hard wired into the camper? So unplug the furnace and see if it still blows fuses?

Fortunately I had it out so many times last season I finally put quick disconnects on those wires. Unfortunately I still need to disconnect the gas line to get to them...someday someone will come out with quick connect gas lines...

I remember coming across that site at some point a few years back. Probably wouldn’t hurt to check it out again.

Thanks!
ZachO is offline   Reply With Quote
Old 05-09-2019, 07:45 AM   #22
Senior Member
 
ZachO's Avatar
 
Name: Z
Trailer: Sasquatch
Montana
Posts: 2,561
Just read something online about possibly a “reverse polarity diode” or something like that in the furnace circuit board that could blow. So, if the wiring tests ok, looks like I’ll be replacing the board again. Brand new last spring! Well, easy to access and still cheaper than a new furnace.
ZachO is offline   Reply With Quote
Old 05-09-2019, 07:46 AM   #23
Senior Member
 
Joe MacDonald's Avatar
 
Trailer: 1981 Trillium 5500
Posts: 1,158
yes disconnect hardwiring at furnace, that way you prove that the wiring to the furnace did not get damaged or nicked and shorted out
Joe
Joe MacDonald is offline   Reply With Quote
Old 05-19-2019, 04:51 PM   #24
Senior Member
 
ZachO's Avatar
 
Name: Z
Trailer: Sasquatch
Montana
Posts: 2,561
It doesn't blow the fuse with the furnace disconnected.

Since I was in there, I took a closer look at everything just in case I could see what was going on. I noticed that the relay looked like it may have heated up. Hard to see in the photos, but there's definitely some melted material. That would explain the burning smell...I think I found the culprit.

Click image for larger version

Name:	IMG_2500.jpg
Views:	16
Size:	213.1 KB
ID:	129426

Click image for larger version

Name:	IMG_2501.jpg
Views:	19
Size:	183.2 KB
ID:	129427
ZachO is offline   Reply With Quote
Old 05-19-2019, 06:34 PM   #25
Senior Member
 
Borrego Dave's Avatar
 
Name: Dave
Trailer: Casita SD17 2006 "Missing Link"
California
Posts: 3,738
Wonder if the connector was a loose fit????
Borrego Dave is offline   Reply With Quote
Old 05-19-2019, 06:57 PM   #26
Senior Member
 
ZachO's Avatar
 
Name: Z
Trailer: Sasquatch
Montana
Posts: 2,561
Not sure..? I know a loose connection is never good, but would it cause an issue with reverse polarity? That wire is the power wire for the furnace. The first place 12v goes when it connects to the furnace is the pop-button 5amp fuse. From there it's the pictured wire, going into the relay. I know it didn't blow any fuses when I had the battery hooked up wrong (but I sure wish it had!).

I don't know enough about electronics yet but it makes sense to me that with the battery hooked up wrong, the first thing power hit which wasn't a wire or fuse, it burned.
ZachO is offline   Reply With Quote
Old 05-20-2019, 11:56 AM   #27
Senior Member
 
Name: Michael
Trailer: Trail Cruiser
Alberta
Posts: 825
I've always thought of a relay as a switch in a high powered circuit that is activated by a switch in a lower powered circuit, as in headlight, horn circuits on a vehicle. Correct polarity is critical. Melting means overheating and likely the need for a new relay.
Mike_L is offline   Reply With Quote
Old 05-20-2019, 01:36 PM   #28
Senior Member
 
John in Santa Cruz's Avatar
 
Name: John
Trailer: Escape 21, behind an '02 F250 7.3 diesel tug
Mid Left Coast
Posts: 2,943
Noting there's a electrolytic capacitor 'potted' into that relay module, and that I can see the top of a NEC EP1F-B3G which *is* a relay also potted in there, that's not just a simple relay, but rather some sort of electronics module.
John in Santa Cruz is offline   Reply With Quote
Old 05-20-2019, 02:24 PM   #29
Senior Member
 
ZachO's Avatar
 
Name: Z
Trailer: Sasquatch
Montana
Posts: 2,561
Well, a new one will be showing up sometime between tomorrow and Thursday. Luckily I still have my Buddy Heater from last spring when I was doing work to the furnace. But I'll be back to furnace heat hopefully before the weekend.
ZachO is offline   Reply With Quote
Old 05-20-2019, 02:33 PM   #30
Senior Member
 
Byron Kinnaman's Avatar
 
Trailer: Scamp
Posts: 7,056
Registry
Quote:
Originally Posted by ZachO View Post
Not sure..?
I don't know enough about electronics yet but it makes sense to me that with the battery hooked up wrong, the first thing power hit which wasn't a wire or fuse, it burned.



Let's try to correct a misconception here. Electricity dose NOT care about the "first" thing in the line. One needs to remember electricity travels at near light speed. In other words very fast. Fuses and other protective devices take time to trip or open up. Things take time heat. Let's take a quick look at fuse, it's piece of metal that is sized to open after some time if more than the rated current is passed through it. However that actual number could be as much as double the rated number. Circuit breakers have a heating element so that when the rated current is exceeded by some amount for some time the circuit breaker trips and opens the circuit.

Hope this helps in some way.
__________________
Byron & Anne enjoying the everyday Saturday thing.
Byron Kinnaman is offline   Reply With Quote
Old 05-20-2019, 03:11 PM   #31
Senior Member
 
ZachO's Avatar
 
Name: Z
Trailer: Sasquatch
Montana
Posts: 2,561
Oh, that should probably help.

I guess I'm not sure why only the furnace had any issues with reverse polarity. The water pump and lights worked. No fuses blew. Apparently just that relay/switch heated up and started melting, and eventually shorted. Not sure how long it would have taken for the fuse to finally blow. Maybe it's more accurate to say the relay was the most sensitive thing in the line that electricity hit.

I read something about a reverse polarity fuse, which is meant to blow right away if you hook up the battery backwards. That seems pretty handy...The relay wasn't expensive, but still another $30ish I wasn't planning for, plus being without the furnace for a couple weeks while I figured it out.
ZachO is offline   Reply With Quote
Old 05-20-2019, 03:37 PM   #32
Senior Member
 
Byron Kinnaman's Avatar
 
Trailer: Scamp
Posts: 7,056
Registry
Quote:
Originally Posted by ZachO View Post
Oh, that should probably help.

I guess I'm not sure why only the furnace had any issues with reverse polarity. The water pump and lights worked. No fuses blew. Apparently just that relay/switch heated up and started melting, and eventually shorted. Not sure how long it would have taken for the fuse to finally blow. Maybe it's more accurate to say the relay was the most sensitive thing in the line that electricity hit.

I read something about a reverse polarity fuse, which is meant to blow right away if you hook up the battery backwards. That seems pretty handy...The relay wasn't expensive, but still another $30ish I wasn't planning for, plus being without the furnace for a couple weeks while I figured it out.



A good hefty diode will work better than any fast acting protection device.
__________________
Byron & Anne enjoying the everyday Saturday thing.
Byron Kinnaman is offline   Reply With Quote
Old 05-20-2019, 03:51 PM   #33
Senior Member
 
The Minimalist's Avatar
 
Name: Clif
Trailer: 08 Weiscraft Little Joe 14 Subaru Outback 2.5i CVT
Louisiana
Posts: 754
Registry
In your second picture, that connector is burned on the outside. I'd be looking for something near it that has a similar burn from contact with the connector. That might not solve the problem, but it may prevent the same thing from happening again when you get it fixed.
__________________
Clif
The Minimalist is offline   Reply With Quote
Old 05-20-2019, 04:16 PM   #34
Senior Member
 
ZachO's Avatar
 
Name: Z
Trailer: Sasquatch
Montana
Posts: 2,561
Thanks, I'll take a good look at everything in there.

It's hard to tell in the first photo, but the black plastic stuff on the relay looked like it had started to melt at that connection. I think the discoloration is from that stuff melting. I'll check everything closely, but I think it's just the relay that got fried.
ZachO is offline   Reply With Quote
Old 05-20-2019, 05:01 PM   #35
Senior Member
 
The Minimalist's Avatar
 
Name: Clif
Trailer: 08 Weiscraft Little Joe 14 Subaru Outback 2.5i CVT
Louisiana
Posts: 754
Registry
I'm not talking about the black discoloration but the little bright silver spot/circle. Looks like someone very small was arc welding on it.
__________________
Clif
The Minimalist is offline   Reply With Quote
Old 05-20-2019, 05:27 PM   #36
Senior Member
 
John in Santa Cruz's Avatar
 
Name: John
Trailer: Escape 21, behind an '02 F250 7.3 diesel tug
Mid Left Coast
Posts: 2,943
thats a sign something shorted up against it.
John in Santa Cruz is offline   Reply With Quote
Old 05-21-2019, 08:24 AM   #37
Senior Member
 
ZachO's Avatar
 
Name: Z
Trailer: Sasquatch
Montana
Posts: 2,561
I think I see what you're looking at. Whether it's a hot spot or just where some of the plastic didn't stick, or is from me pulling the connection and some of the melted plastic getting scraped off that little part...I don't know. But I'll look closer.

To me it doesn't look clean, like it got burned hot there, it just looks like there isn't plastic gunk on that spot. I'll let you know!
ZachO is offline   Reply With Quote
Old 05-21-2019, 11:44 AM   #38
Senior Member
 
ZachO's Avatar
 
Name: Z
Trailer: Sasquatch
Montana
Posts: 2,561
Can anyone explain how reverse polarity would damage the battery? When I winterized the camper last fall, the battery was fine. I pulled it, set it up with my portable solar in the yard for a couple days to charge it, then put it in the shed for the winter.

Then it tested "bad" this spring, after having the polarity reversed. I figure the reverse polarity damaged it. Well now I have a new battery...which was also hooked up backwards for a couple days. I notice it only registers "fair" on my display panel. It'll briefly go up to "good" after some sun on the panels, but never seems to hold there, even with very little power use. So...wondering if battery #2 is damaged, too.

Just wondering, if it matters or I'm able to understand it anyways, how that could happen.
ZachO is offline   Reply With Quote
Old 05-21-2019, 11:53 AM   #39
Senior Member
 
Joe MacDonald's Avatar
 
Trailer: 1981 Trillium 5500
Posts: 1,158
Without getting too technical, reverse polarity effectively kills the battery, then charges it in reverse, damaging the internal battery structure, it may accept a partial charge when connected properly, but will never take or hold a full charge
Joe
Joe MacDonald is offline   Reply With Quote
Old 05-21-2019, 12:07 PM   #40
Senior Member
 
ZachO's Avatar
 
Name: Z
Trailer: Sasquatch
Montana
Posts: 2,561
Hmm. Well I'll have it tested to be sure...but I guess add another expense due to my screw-up!

Would this happen, though, if I didn't do any charging of the battery?
ZachO is offline   Reply With Quote
Reply

Tags
electrical


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Electrical-can't get my electrical heater started. robertmarchiony Problem Solving | Owners Helping Owners 6 09-08-2017 06:11 AM
picture posting change or glitch? WildBirder Forum Admin, News & Announcements 1 01-13-2013 04:08 PM
Electrical problem - Help! scott fraser Problem Solving | Owners Helping Owners 2 08-07-2007 06:03 PM

» Upcoming Events
No events scheduled in
the next 465 days.
» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 01:37 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.