rocklizzard91

ever since ive got my 94 hatch the heater vents dont change, and the buttons dont light up. meaning i cant move air from the floor to the face vents to the defrost. which is very troublesome when i have to defog the car

also i think the recitculate is stuck on closed (again these buttons dont work because i cant hear the flap open/close, and the car fogs up really bad really quickly in the rain)

i need to try to get this working asap.
any ideas of what it could be?
the blower does work.
turns off, and all 4 speeds work.
and a kicker: i have no AC, but the AC button lights up when i press it :confused:

i looked and there is no fuse location for the vent buttons. what should i check next?

phootbag

Perform an input test on the control head.

Also, if the A/C button lights up but the compressor clutch doesn't engage you have a problem with the A/C system. Meaning, other than the control head most likely. Low charge, bad compressor clutch coil etc.

ca-rs

Most likely the servo motor that redirects the flap for vent location.

rocklizzard91

i have no ac installed on the car. so ac isnt the issue. just saying its weird that i dont have ac (no condenser, compressor, anything) and the button lights up, but the other buttons dont.

if the servo motor is dead would that make the buttons not light up when pressed? how would the servo avvect the recirculate?

how do i perform an input test on the control head?

phootbag

I see, I missed the part that you don't actually have the A/C components installed in the vehicle. Sorry.

The reason I say perform an input test on the control head is because you apparently don't have ANY functions working besides the A/C button. You need a wiring diagram that shows the terminals for power and ground.

Also, A/C is essential for keeping fog of your windows during rain. It dehumidifies the air.

rocklizzard91

oh ok. where can i get a wiring diagram?
i have a multimeter, so testing will be no problem. i just dont know which wire does what

ive never needed AC for keeping them fog free.
yes im sure it helps.
but my jetta has no AC and i just make sure its not on recirculate and i just blast the air on each set of vents to combat fogging
if the windshield is foggy, i set it there. when its clear i move to the next window, and so on.

phootbag

I'm not at work so I can't look it up for you, I'll try to remember tomorrow. Or, if someone else has the information and can give it to you before I find it.

Obviously, I would start with fuses and actual ground points since those don't require the removal of the control head to check. I like easy.

rocklizzard91

i couldnt find any fuses that are for the vents.
i looked on the back of my fuse box cover and saw nothing to do with the vents.
but i didnt look in the bay. i can go look there.

phootbag

It's probably an interior fuse not labeled as such, though.

rocklizzard91

hmmm ok i'll just pull them all and check then

Corksil

call me a dumba$$, but i have a 94 del slo. it's about the exact same as a 94 hatch.

afaik, the heater/air flaps are all cable operated. There are cables that control the opening and closing of flaps, not servo motors.

Get a manual for your car, a haynes/chilton should have the wiring diagrams if it is in fact electrically operated flaps. if it's cable operated, you should be able to see pictures that show what cable goes where etc...

I can't tell ya how many hondas have had problems like this, and i take the dash all apart to find a cable that has slipped off the slider/thing the cable operates.

but yes, checking all the fuses would be smart too.

rocklizzard91

the heater uss cable operated, yes. But switching between floor, face, and defrost vents are not

Relic1

A/C switch is powered from a different source. and the light in the switch works even if the A/C parts are not present.

likely the reason why your air delivery system is not working... replace fuse #13

rocklizzard91

Fuse 13 is good. Just walked out and checked.
The blower a works fine if i didnt mention. I just cant move air from vent to vent

rocklizzard91

Fuse 13 is good. Just walked out and checked.
The blower a works fine if i didnt mention. I just cant move air from vent to vent

phootbag

Describing an input test through a message board for a circuit like this is going to be a pain in the ***. But, I'll try.

Fuse 13 supplies power for the Mode Control Motor, Recirculation motor and the Heater Control Panel. Ground for all three is also shared. Since all are affected, I would suspect a problem with Power or Ground. But, we need to make sure to save a bit of money.

BLK/YEL is power input to the Heater Control Panel for the illumination. BLK/YEL is also power at the Recirculation Motor. BLK/YEL turns into LTGRN/RED for power to the Mode Control Motor. BLK is ground from the Heater Control Panel. A splice after the BLK ground terminal at the Heater Control Panel is the ground path for the Mode Control Motor. Ground at the Mode Control Motor is YEL/BLK.

I would confirm all these then test each component individually. YEL/LTGRN is the signal input for the floor position. LTGRN/WHT is the signal input for the face position. Signal is given by the heater control panel buttons....

phootbag

... providing ground paths for these wires. The YEL/LTGRN and LTGRN/WHT wires should have 12 volts at them. When ground is supplied by pressing an individual button, its corrosponding wire should drop from 12 volts to 0 volts. This is a way to test the function of the heater control panel switches.

I have a feeling you're going to remove the heater control panel and find it unplugged.

rocklizzard91

its not unplugged. thats what i checked first. HOWEVER, there are a few larger plugs down under the dash that arent plugged into anything. but i cound no connectors that match them IIRC.
i wont have a chance to really test anything until friday.
so i will post back then.
thanks for the help
i'll let you know how the testing goes on friday

phootbag

You could possibly have discovered the problem then.

rocklizzard91

Ill take pics of said plug and post it

onebad4D

Was your issue resolved?

rocklizzard91

No, I actually got out of hondas before I fixed it and got into a mk2 Mr2, working on a 3rd gen 3sgte (jdm turbo motor) swap