Trojan Boat Forum

Posted: **Thu Sep 15, 2011 12:40 pm**

I have a Norcold DE728 refrigerator, probably was OEM back in 1985. My question is the unit runs fine on shore or gen. power. But will not work on 12vdc. I tried calling Norcold, they do not have a tech department for the consumer, only dealers. They gave me a number for an "Authorized Service Center", I had to explain to them that Marine refrigerators do not work like RV refrigerators. Not sure what to look for has anybody else had this problem?

Thanks

Posted: **Thu Sep 15, 2011 2:18 pm**

From just a quick look online it looks like some current model Norcold reefers can be used in either RV and boats. I would check your 12volts wires coming to the unit, both Pos and Neg. (always check the neg for continuity back to the battery) And check any 12 volt fuses you can find. My Norcold DE0040 has a 12v fuse on top of the fridge.

Posted: **Thu Sep 15, 2011 3:40 pm**

There was another post a couple of months back about someone with a fridge that stopped working on DC as well. Don't know if he ever got his straightened out. Try doing a search on the forum for 'fridge' to see if any other ideas/thoughts show up.

Posted: **Thu Oct 20, 2011 8:33 am**

The fridge has an ac compressor. The module converts dc to ac. Either the transformer or module inverter is likely bad.

Posted: **Thu Oct 20, 2011 8:03 pm**

Have you seen this?
http://www.boatered.com/forum/topic.asp?TOPIC_ID=123146

he has opposite problem... only works on DC. Have you found the inline DC fuse?

Posted: **Fri Oct 21, 2011 9:17 am**

Didn't know it had one. Do you have to pull the refrig to get at it?

Thanks

Posted: **Fri Oct 21, 2011 10:45 am**

abkeywest wrote:Didn't know it had one. Do you have to pull the refrig to get at it?
Thanks

Mine is on the DC wiring to the AC/DC transfer box... since it was a self install it is on the outside of the cabinet.... no idea on your setup.
Suggest you try to follow the DC wires from battery/or panel to the refrig.

Posted: **Fri Oct 21, 2011 11:11 am**

That was me and for the 1st time in my life.... it was the fuse!

The fuse that was installed was undersized. I replaced it and it's worked on 12v DC fine ever since.

Check that first, my fuse was on the unit itself so I had to pull it out to get to it.

Bob

Posted: **Fri Oct 21, 2011 11:46 am**

Have that model in my Carver. The P.O. didn't install the 12v wires ..I had to pull it out to hookem up ..The fuse in mine was on the bottom back side.I rewired it and put it where I can get to it..hope this helps.

Posted: **Fri Oct 21, 2011 1:57 pm**

No guarantees, but someone claims this schematic is for a Norcold DE728
http://www.mumert.com/Norcold.htm

Posted: **Fri Oct 21, 2011 2:05 pm**

If I understand the schematic correctly would the inline fuse be CB1, the breaker?

Posted: **Fri Oct 21, 2011 4:19 pm**

abkeywest wrote:If I understand the schematic correctly would the inline fuse be CB1, the breaker?

I think that is the on/off/thermostat switch within the frig.
The fuse should be inline on the 12V lines... none shown.

Posted: **Sat Oct 29, 2011 10:50 am**

I checked the schematic against the one I got from the electrical area of my 400DE-a and it looks Identical. If anyone should need a schematic give me a shout I have it resized and in PDF for emailing.

Posted: **Sun Oct 30, 2011 9:01 pm**

larryeddington wrote:I checked the schematic against the one I got from the electrical area of my 400DE-a and it looks Identical. If anyone should need a schematic give me a shout I have it resized and in PDF for emailing.

I also have the schematic of my 400A, if anyone needs it. I also found I could reuse the guts of a 704C to fix mine when it crapped out, so I think they are all pretty similar.

There was no 'inline fuse' within the electronics of the fridge itself with either mine or the 704C I cannibalized, so any fuses will be in the wiring before you get the reefer. The DC lines for it (at least on my '79 F32) run from the crossover switch 'black box'.