A/C clutch won't engage

Hey guys, I'm having some peoblems with my A/C. As the title says, the clutch won't engage.

This is what I have done so far.

Connected wire from battery to clutch, engages and works fine.
Replaced the clutch relay.

Probed the wire going into engine from cab that triggers the relay. It never registers any voltage.

Probed the wire coming from the Heater Control box (I think that's what it is) and leads out to the engine bay. It also never registers any voltage.

I put in a new climate control because my old one was cracked all to shit and the holes for the mounting points were broken. Didn't fix it either.

So, my last guess is that the heater control box is screwed. Its the silver box right behind the glove box which a lot of the a/c wires go to.

Any suggestions? Thanks in advance.


P.S. The wire that should trigger the relay is yellow with silver dots. The wire going to the clutch from the relay is red with blue dots.

if it needs charged it wont engage, i assume you have a book on the thing, find the low pressure sensor and use a paper clip or somthin to jump the connector, if it engages then have the system charged

When I jump the clutch to the battery, it immediatly blows ice cold. At any rate, I will try that. Not sure where it is and I don't have a book, but I'm sure I'l find it quick enough.

it'll just be a sensor on a line or on the reciever/drier (the little silver can thingy in the front fender or somewhere) it could be a relay or somthing too but the most common thing is low system pressure

I jumped the sensor and made sure it had voltage. Nada. Still doesn't engage.

now's when you get out the dvom and start checkin stuff, see if you can find some diagrams for the A/C system and look for relays and what not, if you cant find any let me know and what year and model you have adn i'll email em to ya

I don't have the diagrams :( I have a 91 CRX Si. Thanks for the help.