Reply
 
Thread Tools Display Modes
Old 08-19-2016, 11:10 AM   #21
Senior Member
 
DaveSchwartz's Avatar
 
Join Date: May 2014
Location: Waterloo Region
Posts: 666
My white-LED replacement also didn't have this big resistor.

LAC stands for 'Low Ambient Control'. Unlike a fridge in a residence, an RV fridge may be operated where the exterior is not at 'room temperature'. The LAC feature is designed to compensate for this low ambient temperature and keep the fridge cooling properly.

I'm not sure what the purpose of adding 8 watts of heat was (or under what circumstances the control board would have energized it) but obviously they thought it could be cost-reduced out (and a ceramic wire-wound would have cost way more than a nickel).

Its part 'U' just about in the center of the following circuit diagram of the Dometic DMR-702.
Attached Thumbnails
Click image for larger version

Name:	DMR702 Wiring.JPG
Views:	52
Size:	111.7 KB
ID:	117764  
__________________

__________________
2015 Rockwood Signature UltraLite 8282WS Platinum, GY Marathon LRD, TST 507RV TPMS
2005 GMC 2500HD CCSB D/A, Curt E16, Prodigy P2, Garmin RV760LMT w/BC-20 b/u cam

Self restraint is for the young. I'm old and want it NOW!
DaveSchwartz is online now   Reply With Quote
Old 08-19-2016, 04:07 PM   #22
Member
 
Join Date: Jan 2016
Posts: 59
Thanks Dave, that's the same wiring diagram as mine.

If the resistor is near the temperature sensor it may make the fridge run longer and keep the freezer cold when the room temp is low.

I bought a refrigerator last winter for the garage and had to return it because the freezer wouldn't get cold enough at 40 degrees ambient.
I bought one that was "garage ready". It has a heater built in to fool it into running longer.
__________________

__________________

2017 Rockwood 2703WS
2016 F250 PowerStroke 3.55 axle
If women don't find you handsome, at least they should find you handy!
andymil is offline   Reply With Quote
Old 08-20-2016, 12:00 PM   #23
Senior Member
 
raspivey's Avatar
 
Join Date: Jun 2013
Location: Brazoria County, Texas
Posts: 1,276
I'm going to have to go look at mine in the next few weeks. I've got a really noisy fan that's going to have to go in favor of a quieter computer case fan or two. My biggest concern is 12V draw while boondocking for three or four nights. I'm going to install a switch for the fans should I need to disable them...temp should be in the 40 - 70 degree range, so I'm not sure how often or if they'll even run. I'm mostly concerned about the heaters.
__________________
2012 Chevy Tahoe LTZ - HD tow package
2017 Rockwood 2703WS Emerald Edition
raspivey is offline   Reply With Quote
Old 08-20-2016, 12:08 PM   #24
Senior Member
 
DaveSchwartz's Avatar
 
Join Date: May 2014
Location: Waterloo Region
Posts: 666
If the fan is noisy, you certainly have reason to replace it with something quieter but in the temps you are expecting, they should not run... there is a thermostat in-line with the fan (in the schematic I posted). I've only heard mine running in 80+ conditions.
__________________
2015 Rockwood Signature UltraLite 8282WS Platinum, GY Marathon LRD, TST 507RV TPMS
2005 GMC 2500HD CCSB D/A, Curt E16, Prodigy P2, Garmin RV760LMT w/BC-20 b/u cam

Self restraint is for the young. I'm old and want it NOW!
DaveSchwartz is online now   Reply With Quote
Old 08-20-2016, 12:31 PM   #25
Senior Member
 
raspivey's Avatar
 
Join Date: Jun 2013
Location: Brazoria County, Texas
Posts: 1,276
I'd noticed that about the thermostat. It's been so hot here that it's run constantly and I've only had it about two months, so I haven't seen it operate with cooler temps yet. It does appear to be speed controlled with temp. The fan is noisy enough it can be heard on the opposite end of the trailer with the door closed when it's running at high speed.

I've just got to get into it and see how much of a pain it'll be to disable the heaters temporarily if I need to.
__________________
2012 Chevy Tahoe LTZ - HD tow package
2017 Rockwood 2703WS Emerald Edition
raspivey is offline   Reply With Quote
Old 08-20-2016, 01:05 PM   #26
Senior Member
 
raspivey's Avatar
 
Join Date: Jun 2013
Location: Brazoria County, Texas
Posts: 1,276
Quote:
Originally Posted by andymil View Post
There is also a "LAC Heater" on the print, but the wire colors don't match anything I see. I think this is the ceramic resistor, but I'm not sure what it's for. The other lead of the resistor goes to pin 3 of the four pin plug on the light CB. It's marked LAC on the CB.
Quote:
Originally Posted by andymil View Post
Yeah, I just talked to Dometic and they told me that the resistor was not used on that model (DMR702) and it will work fine without it. Just wanted to be sure.
Just looking over the diagram and the PCB, am I interpreting this correctly as this model doesn't use the LAC?
__________________
2012 Chevy Tahoe LTZ - HD tow package
2017 Rockwood 2703WS Emerald Edition
raspivey is offline   Reply With Quote
Old 08-20-2016, 02:47 PM   #27
Member
 
Join Date: Jan 2016
Posts: 59
Quote:
Originally Posted by raspivey View Post
Just looking over the diagram and the PCB, am I interpreting this correctly as this model doesn't use the LAC?
Yeah, that's pretty much what Dometic told me.
__________________

__________________

2017 Rockwood 2703WS
2016 F250 PowerStroke 3.55 axle
If women don't find you handsome, at least they should find you handy!
andymil is offline   Reply With Quote
Reply

Tags
fridge, light

Thread Tools
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




» Virginia Campgrounds

Reviews provided by




ForestRiverForums.com is not in any way associated with Forest River, Inc. or its associated RV manufacturing divisions.

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 10:06 AM.