Hello. I have removed the A/C from my 70 Malibu. I replaced the box on the firewall with a box I ordered from American Graffiti. According to the instructions that came with the new box, you are supposed to mount a resistor/relay on the firewall and plug in the old wiring. I have done this but the fan only works when switched to high. The other fan speeds do not work. Does anyone have an idea on what I did wrong? Thanks for any help you can give me.

Sounds like all you have connected is the high speed relay. Did you install the resistor? Don't know what American Graffiti recommends but the resistor should be installed in the new box so that it is in the air stream. Which requires cutting a hole in the new box. The air flow is needed for cooling the resistors.

To trouble shoot, using a volt meter or test light, make the following checks.

Speed switch in the low speed position, check for voltage on the yellow and dark blue wires at the resistor.

Med 1 position, check for voltage on the light green and dark blue wires.

Med 2 position, check for voltage on the light blue and dark blue wires.

The dark blue wire is or should be connected, soldered junction inside the harness, to the purple wire that connects the high speed relay to blower motor.

Elree, thanks for the reply. There are 2 electric plug-in things, that are screwed into the old A/C box, that was attached to the firewall. There are 2 seperate plugs from the existing wiring harness, that could be plugged into these that I did not reuse. Is this what you are talking about? What I could do is remove them from the old box and attach to the new box. Could this be what I need?

Yes, that is what you need but only one of them. The blower motor resistors (look like coils) is all you need. Install it like Elree said and you should be good to go!

OK, I'll give it a shot tonight. Thanks for your help.

I have removed the air on my 71 and have been considering the a/c/ delete box from american graffiti. Can you give me your opinion on the fit and ease of installation? Thanks

Cruzer, I installed the American Graffiti box on my firewall a couple of weeks ago. It is a nice piece of goods. You will need to remove the inner fender in order to remove to remove the old A/C box and to install the new Amer. Graf. box. After you have the old box out, it would be a good idea to make a template, from it, to use to drill the holes in the new box. The new box does not come with any pre-drilled holes. You will also need to drill holes for the blower motor. Another thing to note, is the fact that you will need to install the blower motor relay, on the firewall, above the new box. In addition, you will need to install the blower motor resistor inside the box as stated above. Good luck.

Thank you for your reply. I currently have the front end off, motor pulled and old a/c box off. The information you have provided really helps. thanks again!!

One more thing, I forgot to mention, is that you will need to put some stuff on the edge of the new box to seal it against the firewall. I used some 3M sealing strips that I got at a local automobile paint shop. They are 12 inches in length and they work great.