CJ/YJ Heater Improvement -- A Novel Idea

[Inspector-Gadget]

good news and bad news

Hello All,

I, like many of you, regularly scan through the tech posts of a few other Jeep-related internet sites. I recently ran across an idea on a Canadian Jeep BB for improving the heater performance of CJ and YJ models. I thought that idea might be worth sharing.

The essence of that BB post: take one CJ/YJ junk-yard underdash air conditioning unit and do some minor plumbing work to enable engine coolant -- instead of freon -- to circulate through the evaporator coil. The evaporator coil is, of course, contained within the underdash A/C unit. The original poster wrote that he connected the Jeep heater core in "series" with the evaporator core (coolant flows sequentially through both cores).

For those unfamiliar with older Jeep A/C-ing, I am talking about this thing:

Supplemental heat and "steerable" heat vents -- one can only dream!

If this setup actually works, it would seem to be a great idea. More heat without the firewall cutting involved with the Blazer heater motor mod (not that one couldn't do both).

What are your opinions of this idea?

Regards,

Gadget

 

[red89yj]

That sounds awesome, but nothing is worse than a muggy rainy day in july, when you have to have the top up. More heat is always a plus, but nothing comes between me and my A/C. another thing that i was just thinking, I remember reading that the a/c unit helps the defroster by "drying" the air before it blows onto the windshield. . .

 

[Inspector-Gadget]

Hello red89YJ,

I agree with you about the value of A/C in a closed vehicle on a hot-muggy day, but my post is not about disabling a perfectly good existing Jeep A/C unit. I wouldn't consider the idea of doing that.

This idea is for CJ/YJ Jeeps which never had A/C or have a failed A/C unit which the Jeep owner is not going to fix.

The purpose of my post was only to present a new and unique (to me, at least) method of adding a supplemental source of interior heating.

Regards,

Gadget

 

[Bounty__Hunter]

Have you seen the mod where the fresh air intake of the heater is blocked, whereas the heater only draws air from inside the jeep, making warm air even warmer.

 

[Inspector-Gadget]

Hi Bounty,

I am aware of the fresh-air-block heater trick, but I wouldn't do that mod.

Call me an old fuss-budget -- which is appropriate because I am an old fuss-budget -- but I think that mod is dangerous. That is an excellent way to asphyxiate by carbon monoxide a perfectly good Jeep owner.

We had this discussion recently. I know one can put the heater controls of many modern vehicles on "recirculate," but most vehicles produced since the 60's, older SWB Jeeps being an exception, also have flow-through ventilation. (Those funny looking grills in the C-Pillars.)

Beyond that caveat, I won't re-hash that discussion.

Regards,

Gadget

 

[Snitty]

looks like a good mod... would one have to get the controls for it as well... i'm sure you could build your own