HVAC Dead after battery change

[32valvesftw]

I had to replace my battery today, no big deal everything went smoothly. Replaced the Bosch with an identical unit. When I fired the car up after the change the HVAC display shows 1 short dash and 2 long dashes, the green light above the auto switch is lit, but none of the buttons respond. I do hear some type of motor running (probably the blower motor) albeit noisily when the key is on and when the car is running. I pulled the AC fuse and the noise goes away and the HVAC display is blank. Any Ideas? I think this is probably why the battery went dead?
Pulled codes following the Factory Service manual nothing shows up.
I have the factory service manual, but I do not have section 8A, which I think I need for this issue,

[Dynomite]

I had to replace my battery today, no big deal everything went smoothly. Replaced the Bosch with an identical unit. When I fired the car up after the change the HVAC display shows 1 short dash and 2 long dashes, the green light above the auto switch is lit, but none of the buttons respond. I do hear some type of motor running (probably the blower motor) albeit noisily when the key is on and when the car is running. I pulled the AC fuse and the noise goes away and the HVAC display is blank. Any Ideas? I think this is probably why the battery went dead?
Pulled codes following the Factory Service manual nothing shows up.
I have the factory service manual, but I do not have section 8A, which I think I need for this issue,

Have you disconnected power before with similar results.....
I disconnect power frequently using a disconnect switch so I do NOT have to charge my battery. ZR-1 fires right up even after several months of disconnect with no re-learning issues. I would disconnect battery for a couple minutes and re-connect.......... then fire it up again just to see what happens :)

Do the battery disconnect/re-connect with switch OFF.

Oh.....and battery will NOT "went dead" with a disconnect switch :cheers:

The Battery Disconnect Switch TIPS (https://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-8.html#post1587653767)

[S.hafsmo]

When I got the three dashes, the C68 programmer was dead. Tried replacing the components in the kit Batee.com sells for these, but unfortunately in my case that didn't work either. Replaced it with a used one from the registry, and was back in business.

From the manual:

SYSTEM DIAGNOSIS
Diagnosis for this system is based on
diagnostic codes stored in the Heater and AIC
Control Head. When a code has been stored the
MODE Indicator (LED) of the current mode will
flash. Three dashes will be displayed on. the
Heater and AIC Control Head if the AIC
Programmer fails.

Diagnosis:
https://imagizer.imageshack.com/v2/800x600q90/924/mWDeJz.jpg
https://imagizer.imageshack.com/v2/800x600q90/924/PABggz.jpg

[32valvesftw]

Thanks for the info, I will try disconnecting the negative and see if it resets. I did try to pull codes from the system following the directions in the FSM, but the auto fan button does not seem to respond, so I can't scroll through codes. I was able to get it to show -00, but that was it. According to the FSM the display gets it feed from the Programmer, so I think the it may be the programmer. I am having trouble finding information regarding the location of the Programmer though. I think it is behind the HVAC head unit in the dash?

[Flyman 27]

I believe that your HVAC programmer is on the firewall above the steering column. VERY hard to get to.
I am preparing to rebuild mine with parts from Batee. I already did rebuild / clean the head unit with Batee parts, since then all buttons & lights work.

[32valvesftw]

Cliff's advise worked, pulled the negative, reconnected it and its all good.
Thanks Cliff, thats twice you helped this car out. When I go to SD to visit my son, I'll buy you dinner.

[Dynomite]

Cliff's advise worked, pulled the negative, reconnected it and its all good.
Thanks Cliff, thats twice you helped this car out. When I go to SD to visit my son, I'll buy you dinner.

Good News :handshak:
What town in SD does your son reside?

Disconnecting the battery (I have disconnected the battery many times on several ZR-1s) does not seem to bother the electronics of the ZR-1 at all and DOES save on battery condition. That is why I was surprised that installing a new battery caused you issues :p

A battery disconnect also provides an anti-theft feature and it is so easy to disconnect the battery with the Battery Disconnect Switch for short or long periods of time with no deterioration of the battery :thumbsup:

The Battery Disconnect Switch TIPS (https://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-8.html#post1587653767)

https://cimg6.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/350x400-1/80-9b113ff3_2c27_4600_aba8_a9f3456647a4_1__3056398d56 5c3bef00aa9bb61a496cedc48f56b5.jpg

[32valvesftw]

Son is in Madison at DSU,
Battery disco is on the list, just have to order one.