tgray41

Hey all

This is my first thread on CherokeeForum.com but I am looking forward to becoming apart of the community. I recently bought my first Jeep, a `96 Grand Cherokee with an I6 and right around 192000. So far I've fallen in love and am getting the upgrade itch. I've started by fixing what wasn't working, simple stuff (driver's side window regulator, cat converter, etc), and then added some black mirrors to replace the painted ones.

As I'm sure I'll be asking often about upgrades like lift kits and lights and wheels & tires... I'd first like to start with something a little more basic (or so I hope). When I hit the heat in my car, it works and heats up just fine, but there's a nasty smell. I'm assuming its all kinds of crap in the heater box, but wanted some expert opinions. I'm also wondering, if this is what the smell most likely is coming from, how involved cleaning the heater box would be. Like is it under all kinds of dashboard and such.

Any and all posts/responses is extremely appreciated and am looking forward to becoming apart of the CF.com community.

Thanks an Best Wishes!
tgray41

wildspear

Welcome to the "Grand Cherokee" life. You can do a quick cleaning of the heater area by dropping the blower motor and the blower motor resistor. The blower motor is held in with three bolts (10mm) and the resistor is held in with two phillips head screws.

Our heater box's get filled up with all kinds of junk from trees and what ever else is around, the junk enters in from the hood vent area and its a short trip to the heater. The smell is probibly coming from debri that is packed up against your blower motor resistor. This resistor heats up quite a bit so its probibly scorching some of the stuff. You'll want to remove that junk as it can lead to a shorter life span of the resistor.

As in any work done around our electrical syestems, disconnect the battery before you mess with the heater. Safty first.

tgray41

@wildspear Much Thanks for the welcome and the advice. It sounds like you hit on exactly what I mean... looks like my project for tomorrow... after I disconnect the battery of course! Thanks again!

Now onto another question... how would I fix the problem of only certain vents working? When I turn the heat/ac on, the only vents that work are the windshield defrost and the floor vents... like some mechanism is stuck on only that setting. Is there a vacuum system on our ZJ's or like a flap system. I'm wondering if/how it would be repairable. Again, any and all insight is appreciated!

Thanks everybody!

wildspear

Almost always, if some vents work and some don't, its the vent doors that have worn out (bushings and such). I don't have the info with me but they do make repair kits for the blower doors. Try search for blower doors. Ill also try to find more info when I get home (om at work right now).

jnicewan

As with almost every vehicle with vacuum controlled HVAC controls the system defaults to the Defroster and you will usually feel some air bleed from the floor. What I would look for first is the vacuum lines that feed the HVAC controls. Most of the time the little black plastic vac line is cracked or broken in the engine compartment. Does the speed control work? part of the HVAC supply line also supplies vacuum to the speed control too.

Look at the little plastic line under the hood. It starts at the intake manifold, runs back to the firewall, has a tee connector real close to the heater hoses, runs along the pass fender to the speed control servo and then up under the battery to the vacuum reservoir. This plastic line becomes brittle with age and engine compartment heat. Sometimes touching or wiggling the line is enough to crack it, so be carefull. If you find a crack or break then goto parts store and get 1-2ft of the smallest vac line avail. Cut small pieces to splice broken line together or buy enough rubber line to fix larger sections.