Originally Posted by acg_ssei

Okay, wish me luck, everybody; I'm using my vacation days to _finally_ (after too many years) get the leaky old evaporator out of the firewall, get a new one in there and get some working A/C once again. As I type this I've got most of the components out of the way and am going in after lunch to get the evaporator/core housing cover off.

Got the factory manuals to guide me on this, and it'* been not-too-bad so far. System had basically nothing left to evacuate; pushed on the low-side Schrader valve anyway just to see if anything would come out, and got nothing but some hot air.

Fittings for A/C accumulator unscrewed nicely without needing the dreaded Special Tool for disconnecting in-line connectors, and accumulator lifted right out. Wrapped it in a plastic shopping bag to keep it clean for now. Also wrapped plastic bags around open A/C lines to keep dirt out of condensor and elsewhere.

Discovered that the vacuum reservoir on the Bonneville is _not_ the usual black spherical thingy seen on older cars, but is a large _cube-shaped_ plastic box on the firewall right next to the brake booster. Wonder how much wrong advice I've been giving out about _that_ thing here, thinking of what the one in my old '82 Cutlass looked like. My bad. :(

Discovered in the course of removing the blower motor that its cooling duct is completely missing, so there'* been a nice 1" diameter hole in the housing, letting engine-compartment air right into the ventilation system all these years. Charming. Also found that the blower speed controller (goes in the same hole as the blower resistor pack on manual-control cars) was held in by 3 different 7mm screws, only one of which looked original, which makes me suspect that some goofball'* had this stuff apart before. (Some months ago when I was installing the remote starter, I found an entire pack of Kool cigarettes with a 1994 tax stamp jammed inside the dashboard.)

Got the underhood fuse/relay assembly detached now, and after figuring out how to release the three big relays on the passenger'* side of the holder, I was able to detach the right and left wiring harnesses into two halves, and swing them completely out of the way.

Can now see the entire top of the housing that needs to come out. Next step is to detach the lower heat shield and some underdash pieces (including the ABS controller, I think) to get at a couple of bolts on the inside, which should release the housing to let me get the evaporator out.

Haven't ordered the new one yet; figured I'd wait to make sure that the old one is leaky and covered with dirty oil and dust, like I'm told I should find when I get it extracted. The local Lee Auto outlet has a new GM replacement available for next-day order, so let'* see if I can get the order in by end of today.

Will check back in here periodically later on, so if anyone'* got any helpful tips for swapping the evaporator, let me know...

Originally Posted by misterfixit1967

I'm interested in your pictures. You mentioned in your last post that you will have pictures available. I am about to undertake the same taskand the pictures certainly would help. Mine is a 92 Bonne sse. Thanks in advance.