68 Camaro AC Blower Fan
I have a 68 Camaro, with Factory AC. My question concerns the blower fan. With the vertical switch all the way UP, the fan runs the slowest. Then 1 click down it's slightly more, then one more click slightly more, than when the switch is all the way down, it slows to the same as in the UP position. What could be wrong? I had this problem, completely replaced the harness, and it's still there.
Probably the blower relay. All lower speeds go through the blower resistor. The blower relay supplies full battery current to the blower, when the switch is in the high position. I couldn't find a diagram for a '68, but on one for a '67, there was also an inline fuse for the relay. Check that too.
I was thinking that, but I'm not sure if the speeds are reversed also. I thought high, med, low and off would be top down, not bottom up. About to order the rely - if that doesn't fix it, guess the only other thing is the switch on the dash. I have the car for 30 years - and lived with it. Now that I'm restoring the AC (everything else done), it's become really annoying. Thanks!
Here is the image I found. According the image, if correct, the fan will always run if the temp lever is not in the off position. The speed switch will not turn the fan off. Don't buy the relay, this might be normal. Speed switch in the "off" position yields low blower speed, when the temp lever is not in the "off" position.
One more thing. The blower will turn off only if the temp lever and speed switch are both in the off position. This should indicate to you, where the "off" position is on the blower switch. From there, the speeds should increment (low, med, high).
I did some more testing. I checked continuity from the horn relay terminal to the end of the orange wire that has the in line fuse. It has continuity. I then removed the in line fuse. This had no effect on the speed of the fan. I suspect that the "high" speed I have is actually a medium. Everything matches the diagram above, exactly. One other thing is the ground under the mounting of the relay. Since the relay is mounted onto the plastic AC box, I guess that's just to connect the relay to the wire, and then the wire is grounded to the firewall through another connection inside the harness. I have continuity from the relay ground to the firewall, but not to the relay. The mounting screw is loose. I guess the plastic is stripped out. Can you confirm that that screw is just into the plastic box, and not into a bracket or something that should have ground. Maybe I should try a small bolt to secure that wire onto the relay??
Dose your relay look like this (see picture)? If so, this relay has a case ground. Power to the relay is supplied by the orange wire. Make sure that the case (metal housing of the relay), has a good ground.
One more thing. The orange wire would connect to terminal #4 on the relay pictured. The black/ground wire, would be attached to the case via one of the mounting holes.
Yep, that's the relay, and how it's grounded. Once I get a replacement relay, I"m going to use a small bolt instead of the mounting screw into the plastic case. Can't seem to get it to stay tight into the plastic case. Relay is probably shot too. Will let you know once I get the new one. Thanks a bunch.
I noticed that there are 2 orange wires for this relay. The smaller gauge wire goes to terminal #4. I've been a mechanic for over 20 years now (Not counting 10 years shade-tree), but will admit to never being under the hood of a '68 Camaro. The information I'm providing you is just what I could dig-up on the Net. My oldest service manual only goes back to 1974. Hope this gets you up and running again,..... GW707.
I ALSO HAVE A 68 & HAD THE SAME PROBLEM HERE IS A 68 DIAGRAM FOR THE 68 SS 350 SB
ALSO THEY DISCONTINUE THIS PART WHICH IS SHOWN N THE PIC BELOW (AMBIENT-TEMPERATURE-SENSOR-SWITCH-A-C- AIR-CONDITIONING ) IN THE BOOK THEY CALL IT ( SWITCH TOOK ME MONTHS TO FIND ONE HERE IS THE LINK TO ORDER 1 http://www.ebay.com/itm/3917359-483326-AMBIENT- TEMPERATURE-SENSOR-SWITCH-A-C-AIR-CONDITIONING- 1968-75-GM-/162117074760 I CHANGED THIS & THE RESISTOR & NOW IT BLOWS MY HAIR BACK...LOL
1 MORE THING WHAT REALLY HELPED ME OUT IS I WENT & BOUGHT THE 1968 CAMARO FACTORY ASSEMBLY INSTRUCTION MANUAL ( 12000 SERIES ). THE PIC'S I POSTED ON HERE R FROM THAT BOOK
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