Heater control questions

[scooter]

This would be on a 82 CJ7 BTW. If I pull the Heat cable and turn the fan on I get some hot air,if I pull the cable that says heat/vent in 2 different positions the first position makes for more air flow but also allows a huge blast of cold outside air from the heater box opening you can see. Pull the same cable all the way and still you get hot air from the heater and now get cold air comming in on the drivers side thru the little air vent hanging under the dash and no cold air on the other side

[Redmanchew]

the heat cable is for a bypass flap that is in your heater box allowing some or none of the air to pass by. this is how the temp is regulated.
the heat/vent/off cable allows no air in in the off if the seals are ok, under vent allows air to be drawn in through the intake to the passenger vent, the center vent (allways open) and the drivers vent (allways open). Both of the latter pass by the heater core pending what temp you have your heat at. Under heat it shuts the passenger vent drawing air from the intake missing the passengerside vent (now closed) across the heater box (pending where your heat knob is pulled out to) to the center and driver side dischage.

[Redmanchew]

sorry slight mistake. when i said the center and drivers side discharge allways open i ment depending on your defrost knob.. it blends between lower vents and the 2 defrost vents.

[only in a jeep cj]

You need to turn the wheel adjuster over by the passenger side air box (between it and the sheetmetal). Vent cable all the way in should be no air flow into the cabin. One pull position out on VENT is opening the cowl vent to allow air forced in from driving OR pulled in via fan. Full out position on VENT opens BOTH drivers and passenger air flow doors for full air flow into cabin.

[John Strenk]

this might be confusing. There are 3 vents. One on the passenger side one in the center on the floor with diverters to the center and drivers foot. and a drivers fresh air vent that is under the dash. Some actually have a duct to under the lip of the dash but most I've seen just open behind the dash.

With the air control off (all the way in) it closes a flap in the intake plenum shutting off all outside air. In the heat or middle position air is allowed to flow to the floor vent or defroster vent. all the way out opens the doors for the passenger side vent and the driver fresh air vent.

The wheel on the passenger side I thought was just to make sure the drivers fresh air vent and the passenger vent close at the same time otherwise, one or the other vent might be left open in the HEAT position.

[scooter]

Adjuster Wheel???? where is this thing you speak of? I do have the plastic duct if you can cll t that that forces the cold air from the drivers side right on at my ...ah well say goods. The passenger side blows in from the opening on the heater box grat/opening you can see if you look at the assemble and its blasts in when your doin 65. With the "air control" cable pushed all the way in to the dash the door in the box seems to be at a 45 degree angle no fully closing and giving a view to the blower cage. Ive tried to push it in with my fingers if the cable was hung up but it appears to go no further. The heather does blow hot air with th etemp control out all the way,air control in all the way but just not much. iread lots of posts about heater improvements id assume this is way cause its pretty inefficent? I ride one of my bikes more than anything anyhow so I just need to remember to bundle up Id imagine.

[John Strenk]

It is a masterpiece of cables and levers.
Here is an overall view:

The adjustment knob is on the far right.

First thing that catches your eye is probably the OFF-HEAT-VENT control. Keep this well lubricated.
Missing is a large washer that covers the post but it was removed to make the movements clearer.

Here are the 3 major positions.

OFF position:



HEAT Position:



VENT position:



Notice also the conditions of the cables. Many of these are bent or the shield is broken. This makes it impossible to move some of the vents.

[scottymac62]

Wow John! Excellent images. Thanks!

[scooter]

Good Lordy.....thank you for the pics and info. At any rate you kinda have to chuckle with a "vent" in a jeep. Its a rolling air leak to start with,specially without the top I will go hang my head underside and see whats working or not.

[scooter]

Ok,everything looks good,the main control works like in the pics and the last item is the adjuster wheel. The flap in my heater box with evertyhing off,cables pushed in has it neither down nor up at a 90 degree angle. Adjusting the wheel I can move the flap quite a bit but have no idea where im shooting for. As it is now looking in thru the grate at the flap I can just see the top edge of the blower cage,is this about right or should it go way up or almost down flat??
Thanks a bunch guys.

[Tager705]

On mine I just pulled the fresh air vent Assembly completely off, its sitting in my living room floor, it improved the air flow allot, and if I want fresh air I just open the window.

[John Strenk]

Originally Posted by scooter

Ok,everything looks good,the main control works like in the pics and the last item is the adjuster wheel. The flap in my heater box with evertyhing off,cables pushed in has it neither down nor up at a 90 degree angle. Adjusting the wheel I can move the flap quite a bit but have no idea where im shooting for. As it is now looking in thru the grate at the flap I can just see the top edge of the blower cage,is this about right or should it go way up or almost down flat??
Thanks a bunch guys.

In the Heat or Center position I would adjust the flap so it just shuts (vertical). This will allow you to draw fresh, dry air from the outside in the winter and it will help keep your windows from frosting up in the winter. If you drive in the winter and use windows in the winter.

[baja67]

I had a similar problem with the passenger vent not closing all the way. Everything was working properly except the door would not shut when the cable was in the correct positions. I took the vent cover off and pushed the lever up on the side until it bumped the stop, door was not closed. Apparently somewhere over the years the flap or door had gotten twisted out of position. I bent the flap back by hand until it was fully closed. Put it back in place and connnected the cable back. Works perfect now. You may have the same issue.

[Mike Romain]

The arm from the hinge pin to the cable came loose on my passenger side fresh air flap so it wouldn't close like yours. I held it in place closed with a coathanger hook and then pulled the handle half way out and used JB weld on the hinge post where it goes into the lever. Has worked for 10 years or so.

I also removed the cables and pulled them to the on position, then drilled a hole in the back side of the base of the knob arm, the size of the red tube for spray white grease. I then let fly in the hole behind with the grease and it came out the far end of the cables. They work nice now.