Hatsuwr

Well, found out my ZJ suffers from a clogged AC condensate drain. The gallon or so of water that suddenly appeared on the passenger side gave it away...

So while the carpets are out drying, I figured I'd put a finer filter on the air intake - just enough to get some of the particles that might cause future clogs.

While I'm at it though, I want to put an air filter at some central location in the air distribution system. Anyone know where I can find a diagram to make some sense of how the system flows?

Thanks!

Hatsuwr

Took off the instrument panel. That was a fun one. Anyway, figured out the HVAC.

There are 5 vacuum control lines which control the HVAC. These are behind the zone selector **** (defrost, recirculate, floor, etc.)

Black is a vacuum reservoir - it goes through the firewall.
Green, when engaged, opens up a panel to let air through the center dash vents.
Brown does the same, but opens up both the floor vents and side dash vents.
Yellow counteracts the Brown line partially and closes just the side dash vents, leaving the floor vents open.
Red leads to just above the blower. It opens a panel which allows air to be recirculated within the vehicle. Otherwise, air is taken in from a small hose that goes somewhere I haven't been able to find yet. From the debris in the fan though, it is somewhere with good access to leaves.
Finally, it seems as if the main defrost vents (along the front windshield) are always open.

I figure I'll put the air filter just behind the panel which opens to allow re circulation. It would be nice if it were more accessible, but this seems like the best option. Once I figure out the external air intake I'll see what I can do about a filter there.

dave1123

IDK if this helps, but when I replaced the blower motor in my 2000 WJ, I looked up the hole it mounts in and saw daylight from the cowl area. There is an optional cabin air filter available for the WJ and it mounts across the air intake for the heater in the cowl. You have to take off the wiper arms and cowl cover plate to get to it. My cover plate mounts with plastic screws but IDK about the ZJ. The heater air intake is a square hole in the firewall that's vertical in the back of the cowl area and I covered it with pet-proof window screen. My cowl was full of pine needles. The guy at the hardware store told me the pet-proof window screen is made out of Kevlar. IDK about that, but my cats climb my storm door screen if I don't let them in quick enough and it doesn't hurt the screen a bit!

Hatsuwr

Thanks for the tip, mine was just about as you described. Still thinking about how I will make a filter for that one, but for the inside (recirculate) filter, I think I have a decent plan.

I don't want to remove the instrument panel every time I need to change the filter, so I'll make one that I can push through the hole for the blower. The blower hole is about a 5.5" circle, and above it spreads to a ~6.5" square.

I figure I'll make a 3 layer filter, with the following:
Carbon Pre-Filter ~$.50 per 6.5" square
30 PPI Foam Filter ~$2.50 per 6.5" square
65 PPI foam filter ~$3.00 per 6.5" square
So, around $6.00/filter. Not too bad.

If I can make it stiff enough then it should be able to rest right above the blower. The foam filters are supposed to be oiled so they won't be working as well as they otherwise might, but I'm not sure what other material I could use that would be okay being crushed a little and then fill out well enough to make a good seal.

dave1123

You can buy household furnace filter material that's a woven matrix of fiber and cut it to any size or shape you want. The stuff looks like someone took black nylon fishing line, clumped it together, and welded it together in a microwave. It's washable and vacuumable. I use it in my furnace because my filter is an odd size, so I just use this stuff over the filter frame. If you oiled it, it would work very well. Grainger has special oil for this.

Hatsuwr

I'll look into that!

Since I had the instrument panel off, I did a few other things.

Installed an amp wire, although I could have done that with it on.
Added some soundproofing/insulation. Not really necessary in those areas I think, but I figured it wouldn't hurt, and I'd hate to realize after reassembly that I wanted it there after all.

I also put in some new foam around the air duct junctions, since the old stuff was almost entirely disintegrated.

Finally, I cleaned the drain for the evaporator, and cleaned the evaporator itself. That thing was nasty. I didn't want to remove the entire unit, so I just cut a small hole in the case and fished what I could out. Used a mirror to check my work and it looks alright. Had I known how bad it was beforehand, I probably would have made a bigger hole...





That's why my AC wasn't working well...



What I could get out with a quick pass with a wire.

jon-d

holly smokes!

dave1123

AH HA! pine needles! They'll get past about everything. It makes me wonder what MY heater looks like. My house has 60' tall pines all around it and I have to sweep off my roof at least once a year. I actually removed my rain gutters because of them. The gutters had shields on them and they STILL filled up.