greetings firstgenfb!

I am a new member with a new bird. Its a beautiful unmolested champagne 67 with its original everything. I was blown away with how well preserved it is and other than a few things querky, its a great car. I am converting the AC to 134a and going through the system and have run into an issue with the fan switch. When I cycle the switch throught the speeds going from the top down, it goes: off - low - med - off. I have checked the resister and replaced the relay. There is an inline fuse going into the relay as well that has constant power from the alt (which i thought was odd). ANy way i need the wisdom of those that have done it before...What should I do to get the fan to cycle throug,h all its speeds?

If it helps ill give some background on the car. Its a 326 2 bbl, auto, PS, AC. The car has been in storage since 1984 and has all its paperwork with it. I have replaced the ductwork to the vents already and comfirmed all the vaccuum lines are connected correctly. Replaced a compressor vaccum cap (little rubber round thing on a plastic dish on the vent switch assembly) Past that it seems to be just as it was 45 years ago.

THanks for the help guys and let me know if any more info is needed to help troubleshoot!

brandon

test the wires and the switch with a voltmeter or testlight

If it's like the '68s, the in-line fuse is for the high speed of the fan only which seems to be speed not working. You checked that fuse?

Jim is correct. The high speed position is derived from a different circuit. Go to the 1967 FB Supplement Manual and look up the Air Conditioner section. It has a schematic and description for how it works.

http://thefirstgensite.com/library/67fbservice/FI67S1B.pdf

Ok after checking and referencing the diagram the fuse works and all seems to be wired correctly. I tried a new relay with no different results. Is there a way to bypass the relay to see if the switch itself is faulty? Or is that unrealistic? Thanks again for the help guys.

Absolutely. The way this circuit works the 18OR line gets energized at the relay to pull the arm over placing 12 VDC directly to the motor via the 12OR wire. You could simply run a 12 VDC jumper from the battery to the relay post holding the 18 OR wire. Word of caution, anytime you lift wires or land jumpers you can F things up real bad, real fast. Be careful. If unsure place a 15 Amp fuse inline with the proposed jumper beforehand. Anyways, you should hear the relay click as it repositions.

If I was a betting man I would guess your problem is with the switch holding the 14BRN and 16Y mounted in the control panel.