Community Forums

garybo · 07-06-2015, 02:29 PM

We have a Norcold N61 frig. I want to add an external fan to the bottom back of the unit via the outside access door. I don't have a question about the fan or location- discussions about these items, temp switches, etc, elsewhere.

There are 2-12v positive wires and 2-12v negative wires going into the frig power/control box pictured. I can splice the fan wires to one each of these + and - main frig wires, matching polarities. Also put in a 1A fuse on the + fan wire. The fan will be on a rheostat to control speed/noise.

Should this cause any problem for the frig operation?

mel s · 07-07-2015, 06:12 AM

Quote:

Originally Posted by garybo

We have a Norcold N61 frig. I want to add an external fan to the bottom back of the unit via the outside access door. I don't have a question about the fan or location- discussions about these items, temp switches, etc, elsewhere.

There are 2-12v positive wires and 2-12v negative wires going into the frig power/control box pictured. I can splice the fan wires to one each of these + and - main frig wires, matching polarities. Also put in a 1A fuse on the + fan wire. The fan will be on a rheostat to control speed/noise.
Should this cause any problem for the frig operation?

garybo
Splice into the pair that supplies the 12V power TO the control box. (aka: the wires going TO the control box)
If both pairs of wires are "going to" the control box splicing into either pair will not be a problem.
HOWEVER if one pair is "coming out of the control box" I would NOT splice into that pair!
Mel
'96 Safari

garybo · 07-07-2015, 10:19 PM

Thanks Mel
You say splice into the + positive wire going to the control box, but don't use the - negative (ground) coming out of the control box, ie, find another ground?

mel s · 07-07-2015, 10:52 PM

Quote:

Originally Posted by garybo

Thanks Mel
You say splice into the + positive wire going to the control box, but don't use the - negative (ground) coming out of the control box, ie, find another ground?

garybo
What I am saying is splice into the pair of 12V wires, both the positive (+) and the negative (-), carrying 12VDC TO the control box...but NOT into the pair of wires (+) and (-) carrying 12VDC OUT OF the control box.

However splicing only into the (+) wire going to the control box and finding another ground (-) as an alternative to splicing into the negative (-) will work perfectly fine.

Mel
'96 Safari

garybo · 07-08-2015, 05:10 PM

OK Mel, I understand.
Thanks,
Gary

garybo · 07-08-2015, 05:44 PM

Well, actually I don't understand.

The 2 + 12v wires go to the SAME terminal on the above LEFT. My Fluke meter display reads +12.9v on both of these wires, measured to each of the - wires, so I don't know which is going "in" or "out".
Can my meter or something else tell me which is "in" and "out"?

STLNLUV · 07-08-2015, 05:59 PM

The 2 pairs of wires shown in your photo are the ones you want to connect/splice to. Connect the +12vdc for your fan circuit to either of the 2 wires connected to the +12vdc on the board in your photo and connect the - (ground/negative/0vdc) for your fan circuit to either of the 2 wires connected to the GND on the board. You should be fine. I assume you are using a computer type fan that draws less than 0.5 amp/ 500ma.

see the last page of the instructions here: http://www.thetford.com/wp-content/u...2306-21907.pdf

Cat320 · 07-08-2015, 06:42 PM

I did that only used AC power, not 12 volt. Plugged it into the back of the refer (Dometic) and controlled the on/off function by a remote located inside the RV.