Interior Heater - What am I missing?

[TrackRat]

1976 CJ5

In the middle of a dash replacement / gauge upgrade. While everything is apart I figure I should take care of the missing components to the heater / ventalation system. I know the fresh air box is jacked (prior owner hacked it up to fit a stereo) - have a replacement on hand. I have all the cables to the dash. Seems like I am missing the defrost duct and the duct from the fresh air box to the heater box. Anything else obvious?

 

[TSB8C]

Looks like you need the air duct from the right side of the fresh air box that then curves down to the heater assembly above the passenger's feet, with the two clamps. You also need the drain hose (with clamp and cap) and the defrost hoses/clamps. And do you have the defrost ducts under the dash? Can't tell from your pic. Optionally you may also want the diverter for the floor heat. While it's out anyway, a new heater core would be good. A common upgrade is to also replace the blower motor. For these earlier style units, the VDO PM322 works well. It's a bit larger and may require a slight mod to one corner of the glovebox, but no biggie.

 

[TrackRat]

Super helpful. Appreciate the picture as well. Where does the Drain hose exit / drain?

 

[TSB8C]

The fresh air box drain is from the bottom of the fresh air box to a hole that is about 1 1/2" in diameter that should be visible just below your heater/air plenum, about 20-24" down from the bottom of the fresh air box and then into the firewall. It is slightly offset to the right of where the air box drain is so the hose doesn't necessarily go straight down. It exits under the battery tray. MTS sells the drain hose and cap that goes on it. Part # CJABH-1. Early CJ Air Box Drain Hose

They also have the duct hose from the air box to the heater assembly, with the clamps. Part # CJABFAH-1. Early CJ Duct Hose

 

[TrackRat]

My new fresh air box has a different mount for the cable control than my original unit. Any suggestions on how to clamp the cable end?

 

[TSB8C]

If you have a pop rivet tool, remove the bracket from the old box and put it on the new one. Or, since the top is accessible (open where you can get your hand in there), just drill out those existing rivets and use a pair of small screws with lock nuts on the inside to mount the bracket. I wouldn't mess with trying to jerry rig a way to secure the cable to a bracket not made for it.

 

[TrackRat]

The fresh air box drain is from the bottom of the fresh air box to a hole that is about 1 1/2" in diameter that should be visible just below your heater/air plenum, about 20-24" down from the bottom of the fresh air box and then into the firewall. It is slightly offset to the right of where the air box drain is so the hose doesn't necessarily go straight down. It exits under the battery tray. MTS sells the drain hose and cap that goes on it. Part # CJABH-1. Early CJ Air Box Drain Hose

They also have the duct hose from the air box to the heater assembly, with the clamps. Part # CJABFAH-1. Early CJ Duct Hose

Thanks for the lead on the Duct Hose. Had ordered what I thought was the right part from Summit but was way too short. Used the link provided to grab one from 4x4partsdude.com who were super helpful.

Another Q… what (if anything) does the opening to the right of the outlet for the defrost hose connect to?

 

[TSB8C]

There are actually two defrost hose connections on the top. The right one is hard to use due to the drain hose. So many people just cap off that right one and just use a single defrost hose on the left with a funnel shaped defrost duct like in the pic I posted.

 

[TrackRat]

Perfect. Just installed a duct similar to the one in your picture yesterday. Prior owner had a jelly jar top over the second opening. I’ll give it a nice coat of black paint and call it a day then. Thanks again!

 

[bcstringer]

I just wanted to thank you all for this post and answers! I have a 1972 CJ5 . I also ordered an oval fresh air duct hose that I thought was the right size but it was too short at 11"-12" long. Hopefully the 15" CJABFAH-1 I just ordered from MJW Jeep Parts will work now. Also, I found a 2.25 in black vinyl cap Item # 41223 at US Plastic to cover up the open port on the right next to the port that receives the defrost hose. It sure is hard to find these old CJ parts these days!