As I mentioned yesterday, we had just had the vehicle air conditioning serviced, but that's only making sure there is enough coolant in the AC system. Some experimentation showed that the compressor was still working and a slight amount of cool air (mainly what airflow forces through the system by driving down the road, which isn't much) was coming through. Cold air came from the rear vents in the back of the minivan and we could hear the fan running back there. So it was the fan that was the issue, or possibly the switch to the fan, which has failed before. (The rear fan is on a separate switch.)
When we stopped at the grocery store, Lisa checked what would have been the easiest issue: the fuse. That wasn't it; the fuse was intact. That means either the switch or the motor. There was nothing more we could do that night. We made it home (fortunately the worst of the heat was behind us) and looked into options. Lisa opened up the Astro and determined that it was probably the motor because she could detect current downstream from the switch.
As soon as the Chevrolet dealership in Reno opened on Monday, I called to look into getting a replacement for what we have now learned is technically listed as a "blower motor." The dealership could not supply us with a GM part for our 1989 Astro. Such parts exist, but they are special orders and would take too long to get here.
Auto parts stores in Fernley sell aftermarket replacements, and we got one from O'Reilly. It causes Lisa's teeth to grind to have to buy Chinese-made parts, but it only has to last a few weeks. We can look into getting a better replacement when we get home from Kansas City.
We made three trips to O'Reilly yesterday. The first was to buy what we thought was the correct part. Then Lisa discovered what the real problem was: what the shop guide for the Astro calls a "cooling tube." This is a small rubber hose that looks similar to this one, although the site says that the one pictured is not actually compatible with our minivan. The problem is that even with pictures and part numbers and shop manuals, the parts stores around here can't find an equivalent part. A plain rubber hose isn't enough: the ribs on one end fit into a hole in the blower motor.
Why is this hose important? Well, the cold air from the cooling system feeds into a box inside the engine compartment where the "squirrel cage" fan that the blower motor turns pushes the air into the vehicle's duct work. At the front bottom of the air compartment is a fitting. This cooling hose attaches there and runs up into the blower motor. This allows some of the cool air to actually cool the motor itself. Without this hose, the motor will overheat and die, and Lisa says that's what happened here.
It is at least possible that if we took the Astro to a GM dealer and left it with them for a couple of weeks, they could eventually track down both a GM blower motor and the specialty tube. But we don't have weeks. We leave on Thursday afternoon. While having working air conditioning isn't absolutely required to make the vehicle run, I don't want to make the trip without it.
The third trip to O'Reilly was to trade the motor we originally bought for the correct one for our minivan. It turns out that there's a different motor depending on whether you have the optional rear air conditioning fan, which we do. It makes a difference because the cooling tube inlet is on the other side of the motor for the other part, and the motor does not have rotational symmetry. Fortunately for us, Lisa was able to get the old motor off without damaging the "squirrel cage" fan, which is good because the correct part doesn't come with the fan. OTOH, that means it also doesn't come with the specialty washer necessary to make the squirrel cage engage with the fan motor, and which wasn't on the original motor because the factory design didn't need it.
Lisa dug through the garage and found washers that were (intentionally) not quite big enough to fit on the blower motor spindle. She then used the drill press we bought from Adrienne Foster's father's estate to widen the hole a little bit, and then she used a metal file to file two sides of the slightly-larger hole flat so that it would engage correctly with the spindle. Thanks to her improvisation and the parts and tools with which the garage is filled, she was able to get the squirrel cage to correctly engage the spindle so that the fan would turn when you applied power to it.
Next was a work-around for the cooling tube. Fortunately, the fitting is not a high-pressure fitting. Air flows through no heavier than the fan forces air through the car's AC system. It's not like the vacuum fittings that failed on last year's road trip that would pop off under use. So Lisa used large amounts of electrical tape to seal the end of what's left of the cooling tube to the cooling inlet on the blower motor. It doesn't have to be perfectly air-tight, but it does need to let most of the air coming through the cooling tube get into the motor; otherwise, the motor will simply overheat and burn out again.
After three trips to the parts store and considerable improvisation with washers and tape, Lisa undertook to fit the replacement blower motor into the minivan. It was around 9 PM, which did mean it was comfortable temperatures in which to work, although the bugs drawn to the shop light were annoying. I held the shop light and handed Lisa tools as she directed.
Here is the blower motor (dark black object near center) installed in the air housing (grimy grey-black box). The cooling tube runs between the bottom of the blower motor and the air housing. You can see generous amounts of tape holding the tube to the motor. There is also tape on the housing because the generic aftermarket blower motor didn't exactly cover the air housing, leaving a gap through which air would leak, and Lisa sealed that up with tape.
Before reinstalling the radiator coolant recovery tank and the windshield washer tank, which sit in the empty space in the photo above, Lisa had me turn the minivan's ignition to On (but to not start the engine) and turn on the fan: success! the blower motor works and pushes air through the system. Lisa reinstalled the two tanks, put away the tools, and cleaned up.
Lisa said, "If I get this installed and working, will you order us a pizza?"
I said, "No." She looked startled. I explained, "I can't. It's after 10 o'clock, and everything is closed." Lisa allowed as that was a pretty good reason. I offered to take her to Denny's (our only 24-hour restaurant in town now that Amazon moved out of Fernley, taking with it the late-shift workers that justified late-night restaurants), but she decided to just call it a night.
Lisa is worried that the repairs may not hold. I, however, am astonished that Lisa got it to work at all. Assuming that keno ticket didn't drain all of our luck away, this should hold together long enough to get us to Worldcon and back, after which we can look into getting better replacement parts more or less at our leisure.