My father in-law's corvette's ventilation fan has just started to run non-stop with the air being ported to the windscreen demister, even with the ignition completely off and the air conditioning control panel removed. I've tried adjusting the fan speed using the air conditioning control panel, the fan speed doesn't change, but the air conditioner will clutch and de-clutch and the airflow will change from demister to the front vents.
Does anyone know the Air Conditioning Control panel button sequence to get it to display the faults codes?
From other forum advice, it looks like the blower control unit is probably faulty, I'm guessing the the control unit is underneath the evaporator.
Here's a link to some photos of the Control Panel and under the hood.
If someone is also able to tell me what the relays are that are on the side of the evaporator box, that would be great to.
https://onedrive.live.com/redir?resi...hint=folder%2c

 

it's on youtube for the self testing control

 

Earlier than '90 C68/automatic AC builds weren't capable of that diagnostic display. The generally considered "fix" for your condition is the replacement of the blower control module on top of the evaporator case in LHD builds. I don't see it or anything similar in your snapshots. You mention underneath and that seems very likely.

Your situation is considerably different possibly in that your car is RHD so the evaporator module is dramatically different. The relays on your evaporator case are in/near that location on LHD conventional builds and the evaporator case was an appropriate place to anchor them.

The 14078915 #'d relay was generally/frequently used as a fuel pump relay, the 14078902 #'d was more commonly found to be cooling fan control in GM builds of the time. The relay with no visible GM# also has "wire to wire" splices so that is a relocation I'd guess of sorts by the RHD fabricator OR a service part from a later repair. Maybe the 2nd cooling fan relay if the car has an AUX fan. Post the wire colors on the other end of the "wire to wire" and the wire colors could be used to ID it. The same for the relays with GM #'s, wire colors maybe to ID the controlled device. I see maybe a more recent relay addition in one of your snapshots.

It might be easier to help if you mentioned the year of the build and maybe your location.

In this thread is a snapshot of connector/control from an '89 it's mentioned. You should find similar "under/bottom of" your evaporator/blower case maybe.

https://www.corvetteforum.com/forums...post1589952806


I might be interested in you "showing me" -

 

I did not know the older ones did not do this I have a 94. learned something new thank you.