2016 GT Refrigerator not work on DC power

[cjrdad]

Both refrigerator and freezer work fine when plugged in but only the freezer works on DC power like when driving. I haven't checked but I am assuming they both work on generator. Ideas?

[DavidEM]

I assume that this is a three way fridge: 110V, 12V and propane. First DC provides a fraction of the cooling of the other two sources. Why not run on propane while on the road? It works fine.

David

[cjrdad]

Actually, unlike the fridge in trailers, compressor fridges are in Interstates and do not run on propane.

[Pahaska]

In the 2016 GT, the refrigerator and freezer are separate compressors with separate hookups to 12v. Both are on the same fuse. It is very possible that there is an open connection to 12v for the refrigerator. I'm afraid you really have to pull the refrigerator out to find this one. Look for a bad crimp or loose connection.

Since 120v is converted to 12v in the refrigerator controls, it will work on 12v if the connections are good.

[Al and Missy]

Originally Posted by Pahaska

In the 2016 GT, the refrigerator and freezer are separate compressors with separate hookups to 12v. Both are on the same fuse. It is very possible that there is an open connection to 12v for the refrigerator. I'm afraid you really have to pull the refrigerator out to find this one. Look for a bad crimp or loose connection.

Since 120v is converted to 12v in the refrigerator controls, it will work on 12v if the connections are good.

I don't own an Interstate, but if the compressors always work on 12 volts and are supplied by one fuse, how would it be different depending on where the 12V comes from, the batteries or the converter?

[cjrdad]

Originally Posted by Pahaska

In the 2016 GT, the refrigerator and freezer are separate compressors with separate hookups to 12v. Both are on the same fuse. It is very possible that there is an open connection to 12v for the refrigerator. I'm afraid you really have to pull the refrigerator out to find this one. Look for a bad crimp or loose connection.

Since 120v is converted to 12v in the refrigerator controls, it will work on 12v if the connections are good.

Thanks, John.
I was afraid of that...

Anybody have tips on removing the fridge? I'll search the forum also.

[Pahaska]

Originally Posted by Al and Missy

I don't own an Interstate, but if the compressors always work on 12 volts and are supplied by one fuse, how would it be different depending on where the 12V comes from, the batteries or the converter?

Because, as I posted, each compressor is fed separately. They are fed through crimped push-on connectors into the control circuits on the back of the boxes. Here is a snip from the owner's manual that shows exactly what I posted.

There was a recent post on a different problem that was traced to a bad crimp done by Airstream. I developed hardware for 35 years for IBM and I would rate this a high probable. First. make sure 12v is getting to the box.

Another possibility is that the switch-over circuitry between 120v supplied 12v and direct 12v in the refrigerator has failed. This would require replacement and I would check the wiring first.

[Heckler56]

Originally Posted by cjrdad

Thanks, John.
I was afraid of that...

Anybody have tips on removing the fridge? I'll search the forum also.

There have been a couple recent posts on removing the frig. Wxboxy posted a couple weeks ago. As I recall the first big tip is remove the door. Then know as you get to the point of sliding it out the 12v connectors on the back will not allow you to fully remove the frig. and a second set of hands to uncouple those are helpful. Then just add some wire length for future removal.

[Al and Missy]

Originally Posted by Pahaska

Because, as I posted, each compressor is fed separately. They are fed through crimped push-on connectors into the control circuits on the back of the boxes. Here is a snip from the owner's manual that shows exactly what I posted.

There was a recent post on a different problem that was traced to a bad crimp done by Airstream. I developed hardware for 35 years for IBM and I would rate this a high probable. First. make sure 12v is getting to the box.

Another possibility is that the switch-over circuitry between 120v supplied 12v and direct 12v in the refrigerator has failed. This would require replacement and I would check the wiring first.

While the compressors are wired separately, they run on 12 volts only. OP said they both work on shore power but not on battery. So it can’t be a problem with the wiring to the compressors.

Is there a separate feed in the fridge for shore power to develop 12 volts? Why wouldn’t the converter provide 12 volts from shore power on the same wire as the batteries? It seems overly complex to convert shore power to 12 volts in both the converter and the fridge. But then I don’t own an Interstate so what do I know?

[Pahaska]

Originally Posted by Al and Missy

Is there a separate feed in the fridge for shore power to develop 12 volts? Why wouldn’t the converter provide 12 volts from shore power on the same wire as the batteries? It seems overly complex to convert shore power to 12 volts in both the converter and the fridge. But then I don’t own an Interstate so what do I know?

There are really two totally separate refrigerators in his coach, one of which is being used as a freezer. They are compressor refrigerators, totally different from your adsorption refrigerator. They run on mains 120v power when it is available rather than use 12v converted power. That frees up more 12v power from the converter for the rest of the coach and for charging the batteries. When there is no 120v power available, the refrigerators default to 12v and run off the batteries.

If you will look at the diagram in my last post, you will see 4 connections to the refrigerator that are separate from connections for the freezer. Those are what need to be checked. If that is the problem, then the hardware is good. If there is a solid 12v and ground getting to the refrigerator portion, then the problem is probably the switchover circuitry.

[Al and Missy]

Originally Posted by Pahaska

There are really two totally separate refrigerators in his coach, one of which is being used as a freezer. They are compressor refrigerators, totally different from your adsorption refrigerator. They run on mains 120v power when it is available rather than use 12v converted power. That frees up more 12v power from the converter for the rest of the coach and for charging the batteries. When there is no 120v power available, the refrigerators default to 12v and run off the batteries.

If you will look at the diagram in my last post, you will see 4 connections to the refrigerator that are separate from connections for the freezer. Those are what need to be checked. If that is the problem, then the hardware is good. If there is a solid 12v and ground getting to the refrigerator portion, then the problem is probably the switchover circuitry.

I was misinterpreting the diagram. I finally understand. The shore power wiring isnt shown. Sorry for injecting confusion.

[cjrdad]

Good news to report!
I removed the fridge (Thanks Heckler56!) and found one of two 12v connectors was loose(like John suspected). Fully seated the connector and problem solved. Thanks John!

Paul

[Pahaska]

You are welcome. 35 years of developing hardware paid off!