92 k1500 5.7 4x4 Climate controls not working

[nhelmar19]

Got a little bit of an obscure one for you guys, I recently purchased a 92 k1500 5.7 4x4 and the truck didn't come with a climate control unit. I went on eBay and bought a unit with the "RECIRC" and A/C button (its an ac truck so i assumed that much) got that unit installed then powered it on only to discover it didn't. Long story short the original 12v ignition and ground wires werent working correctly so i connected them to the aftermarket radio the 12v constant, ignition and ground are shared with the radio wires now. After getting those wires hooked together the unit powered on fine and appeared to be working, i adjusted the vents from head to foot and i can hear the actuators working under the dash but then the arrows showing where currently selected vent start flashing. Maybe 30 seconds after those start to flash every arrow above the temperature indicator also begins to flash. I can hear the door moving when adjusting the "cold to hot" bar but every arrow continues to flash on the display. The blower motor doesnt do anything regardless of whats going on with the display. Picture below is with all the arrows lit on the heat cold indicator and the bars to the left of the person except it would be flashing unlike in the picture lol.

So basically im wondering if any of you have had this issue and what suggestions would be? I know its fairly involved to get the blower motor out but if that would be the problem i dont care. My issue now is ive thrown 300 bucks at this problem on top of the 2k i paid for the truck so its getting a little frustrating.

Other information if it makes a difference to diagnostics: Went to fill the ac system and it had no pressure in it, the interior was swapped from another truck. Previous owner couldnt confirm what the previous climate unit looked like, i also tried a climate control unit with the "max" button instead of recirc but nothing changed.

 

[Dropped88]

Im fairly certain 92 didnt have max or recirc because those control heads had 4 speed control and the older one where only 3 speed. And the flashing arrows is actuators faults which again i believe are different on 93+.

And i also have a 92 in my fleet which is only 3 speed and no max/recirc

 

[nhelmar19]

Im fairly certain 92 didnt have max or recirc because those control heads had 4 speed control and the older one where only 3 speed. And the flashing arrows is actuators faults which again i believe are different on 93+.

And i also have a 92 in my fleet which is only 3 speed and no max/recirc

Would the incorrect unit also cause the blower motor to be non responsive?

 

[someotherguy]

It does sound like a mismatch on the controls, however I would also have to question why was it missing the controls in the first place? Did this interior swap include more than just seats and panels? Hopefully you still have the original 1992 HVAC box so that the correct 1992 controls will help towards solving the issues.

Richard

 

[nhelmar19]

It does sound like a mismatch on the controls, however I would also have to question why was it missing the controls in the first place? Did this interior swap include more than just seats and panels? Hopefully you still have the original 1992 HVAC box so that the correct 1992 controls will help towards solving the issues.

Richard

As far as I've been told the HVAC equipment is original to the truck, the dash pad and seats/carpet were what was replaced. As long as the HVAC is original does it sound more likely that a simplified control unit would solve the problem?

 

[Dropped88]

My opinion is get the correct control head and see what works from there. I know 88 & 89 is compatible but i dont know whats compatible from 88-91 with 92 if any of those are

 

[someotherguy]

My opinion is get the correct control head and see what works from there. I know 88 & 89 is compatible but i dont know whats compatible from 88-91 with 92 if any of those are

90-92 should be compatible; don't know on 88-89 but those would stand out as the face is black instead of gray. I used a 90 HVAC box complete swapped into my 92 when I was putting it back together from being stolen and stripped. The 92's HVAC box was damaged from a prior crash.

Richard

 

[evilunclegrimace]

My '92 has the six button control head in it like the OP showed in his pic.

 

[nhelmar19]

My '92 has the six button control head in it like the OP showed in his pic.

Well damn it

 

[studigggs]

I believe 88-90 were without max/recirc and '91 and up had the button. 88-90 also require a different fresh/recirc actuator under the glove box (5 pin).