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Defender 90 1995/Wynn's A/C Repair

My Wynn's A/C unit started making a horrible squealing noise... right before it smelled of burning plastic. That's not a good combination. Another piece of the puzzle is the fact that the NAS Defenders were offered for four years and each year had a different A/C system! Upon dismantling the unit, I discovered that the source of the problem was, as expected, a blower motor fan, which had cracked and was rubbing against the housing, which was also broken.

Quick Parts/Special Tools List:

The blower motor is a Spal 006-A40-22, which is still available from Spal (http://www.spalusa.com) for $165 at the time I'm writing this. From talking to the guy at Spal, there is also, apparently, a new part number for it: 3006707, but they had several of the 006-A40-22s on hand, so I got one of those.

Spal does not sell the fan blades a la carte, so good luck finding replacements! But, for that $165 you get an entire new assembly that bolts onto the evaporator housing. It's not exactly the same, but it's a little beefier and has a stronger housing. The important parts are the same and the bolt pattern is identical.

Basic procedure is:

  1. Reclaim refrigerant from A/C system
  2. Remove two plastic trim panels from the left and right of the evaporator housing (small Phillips-head screws
  3. Unclip main wire harness located next to the refrigerant pipes and unclip the three wires from the speed resistor
  4. Remove the four hole plugs, air bezels, and Phillips-head screws securing upper A/C housing to the dash; remove upper A/C housing from vehicle
  5. Disconnect two refrigerant pipes to/from evaporator (it's already discharged, right?)
  6. Remove three M11 nuts securing upper evaporator housing to dash
  7. Remove two M10 nuts (mounted vertically) that hold the rear/top lip to the dash
  8. Disconnect +/- electric wires at motor and remove evaporator unit from the vehicle

So now it's out! Clean things up and unscrew the four Phillips-head machine screws towards the four corners of the blower motor housing. They're attached to the evaporator coil via speed nuts and the bottom two should be nicely rusted by now due to years of exposure to condensation, so be careful to not strip the screws. Additionally, now is a great time to replace the old foam gasket that has probably deteriorated completely by now with something fresh. Just scrape off the old one, remove the ancient adhesive, and reapply new strips. I also recommend a bead of silicone sealant against the blower/housing joint, otherwise condensation will find its way onto your floorboard before it gets to the drain hole. Attach your new blower motor unit and reinstall the assmebly onto the dash.

The wiring is a bit different due to the different resistor setup. I opted to use the blower motor's resistor and bypass the old looks-ready-to-fail-at-any-moment resistor on the upper A/C housing. This did raise the lowest setting up a bit... now I've been using the lowest setting as my default! Just be sure to test out the blower operation before you put everything back together and especially before you vacuum the system.

Once you're satisfied with the blower motor operation, replace all of the o-rings in the joints that you disrupted with new r134a-compatible ones. Oil them slightly with PAG oil before installation. Replace the receiver/drier and the o-rings there too, then pull a vacuum on the system and do a quick check to make sure there are no gaping holes; then thoroughly vacuum the system for at least 1 hour, but the longer the better, and do a 30-minute (or longer) leak-down test to make sure it can hold the vacuum.

Charge the system up with 32oz. r134a and enjoy your noise (and smell)-free A/C!

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