What happens when you connect the battery BACKWARDS

RedHorse1 · 06-02-2018, 09:44 AM

What happens when you are distracted?

You hook the battery up backwards.

Yup, guess what I did. So what happens? Well, what happened to me?
1) the 4 reverse polarity fuses blew (25A).
2) 15A fuse protecting the stereo, LP/CO detector, 12V to the antenna
3) here’s the biggie: the 2A glass tube fuse in both thermostats (ColemanMach)
And, they are different lengths! Applied a “temp field fix” (I cheated) by wrapping them with alum foil.
I found the longer fuse pretty easily (abt 1 1/8” long) but the shorter one (abt 3/4” is proving scarce.

I had spares for the spade fuses but none of the tubular ones for the ‘stats.

The moral of my story? Pay attention and carry spares, you can’t have too many!

Jagiven · 06-02-2018, 11:23 AM

That sucks. I think I have a few spares for everything but, the 1 or 2 amp spade fuse in the refrigerator control board. I have looked a few times for it, but I have not been successful.

The radio is tricky as there is a glass tube, fuse behind our radio. You have to remove the radio to access it.

Iraqvet05 · 06-02-2018, 01:02 PM

I did that once and the blew all the fuses you mentioned. I need to put red tape or heat shrink tubing on all my positive wires to remind me what goes where.

RedHorse1 · 06-02-2018, 01:22 PM

Quote:

Originally Posted by Jagiven

That sucks. I think I have a few spares for everything but, the 1 or 2 amp spade fuse in the refrigerator control board. I have looked a few times for it, but I have not been successful.

The radio is tricky as there is a glass tube, fuse behind our radio. You have to remove the radio to access it.

Don’t know if our radio has its own fuse or not, the one protecting it in the main panel was burnt, replacing it did the trick. The fuses in the t’stats are glass too and proved to be elusive. I found the shorter one in a “multi-pack”, $4 to get the one I needed but I didn’t want to leave my alum foil solution in place any longer than necessary.
Live n learn and hopefully remember.

GarlicDude · 06-02-2018, 01:44 PM

I just finished checking some electrical stuff on our TT with my multi and made a note to have that in my toolbox on the trailer. Have box of blade fuses, but will see what others I might need.

Best,
Steve

Jagiven · 06-02-2018, 01:47 PM

I keep my spare fuses in a Tic Tac container.

RedHorse1 · 06-02-2018, 01:49 PM

Quote:

Originally Posted by GarlicDude

I just finished checking some electrical stuff on our TT with my multi and made a note to have that in my toolbox on the trailer. Have box of blade fuses, but will see what others I might need.

Best,
Steve

If you have the ColemanMach t’stat it probably has a fuse. The front cover pulls off on mine and the fuse is near the low right corner.

us71na · 06-02-2018, 03:33 PM

Quote:

Originally Posted by RedHorse1

The moral of my story? Pay attention and carry spares, you can’t have too many!

When you get home label your cables! Or get some of these.

michael.g · 06-02-2018, 07:58 PM

I was happy to see Jayco labeled the battery cables on our Bungalow. I removed the battery at the end of last season. While driving up for the season this year, I was trying to remember how the battery was situated and how I would know which is which.

-Michael

travelingjw · 06-03-2018, 07:34 AM

I was lucky, it only blew the 30 amp fuse at the front of the trailer. I then installed a 30 amp breaker. Look up "fuse assortment" on Amazon. I bought one of these and have needed the fuses multiple times.

jasum · 06-03-2018, 01:47 PM

Quote:

Originally Posted by RedHorse1

What happens when you are distracted?

You hook the battery up backwards.

Yup, guess what I did. So what happens? Well, what happened to me?
1) the 4 reverse polarity fuses blew (25A).
2) 15A fuse protecting the stereo, LP/CO detector, 12V to the antenna
3) here’s the biggie: the 2A glass tube fuse in both thermostats (ColemanMach)
And, they are different lengths! Applied a “temp field fix” (I cheated) by wrapping them with alum foil.
I found the longer fuse pretty easily (abt 1 1/8” long) but the shorter one (abt 3/4” is proving scarce.

I had spares for the spade fuses but none of the tubular ones for the ‘stats.

The moral of my story? Pay attention and carry spares, you can’t have too many!

RedHorse you are supposed to take a pic of batteries BEFORE unhooking anything...........

Colorado · 06-03-2018, 03:25 PM

I put these on every battery, just a little extra visual recognition.

Atlee · 06-04-2018, 05:08 AM

My positive battery cable is red. Are other folks trailers not red?

Quote:

Originally Posted by Iraqvet05

I did that once and the blew all the fuses you mentioned. I need to put red tape or heat shrink tubing on all my positive wires to remind me what goes where.

WeRJuliian · 06-04-2018, 06:00 AM

As has been noted, labelling wires is always good.

Whenever I take anything apart, I take a picture or, failing that, a sketch on the traditional "back of an envelope", to avoid those "Where does this bit go?" moments.

RedHorse1 · 06-04-2018, 06:42 PM

I have no excuse.

The cables are labeled with narrow “+” and “-“ strips, black is pos and white is neg. I was talking to someone at the time and wasn’t paying attention and my report is the outcome.
I’ve found that when my “normal” routine is interrupted I can easily forget something. I’ve tried checklists but find I don’t carefully follow them too, the interruption issue again.
Anyway, I’ve recovered from this and anxiously waiting on my next “foul-up”.

us71na · 06-05-2018, 07:29 AM

Quote:

Originally Posted by Atlee

My positive battery cable is red. Are other folks trailers not red?

My positive wires are black, the ground is white.

ALJO · 06-05-2018, 08:26 AM

Redhorse1: we all have been there one time or another even if we are careful and responsible. If they run out a certain color on the line, you think the line would stop? They use the nearest matching color. So don't feel bad, we all pay for our mistakes the odd time.

Iraqvet05 · 06-05-2018, 09:19 AM

I don't understand the logic behind the cable coloring here. Nearly every 12v/24V DC system I have worked on as a civilian and as an Army mechanic used the red/black coloring scheme. However, the RV industry (at least Jayco) uses black and white like you see in a stick and brick 120V AC system. When all your POS wires are black on the TT but your car has a black NEG lead, you have to think twice. For me, it's not a matter of marking the battery terminals, but keeping the wires straight.

Riich · 06-05-2018, 05:23 PM

This was my mess before I properly color coded red to positive and black to negative. Notice how the red and black paralleling cables aren't even hooked up right. And the black/white combo just doesn't work for me.

us71na · 06-06-2018, 12:27 PM

Quote:

Originally Posted by Riich

This was my mess before I properly color coded red to positive and black to negative. Notice how the red and black paralleling cables aren't even hooked up right. And the black/white combo just doesn't work for me.

Actually it looks like it was orginally connected correctly with the two black wires connected to the positive terminal and the white to the negative, which is standard trailer wiring.

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