1965 Rear Ventilation Motor In-operable

[James W.]

[George C.]

Re: 1965 Rear Ventilation Motor In-operable

James,
I do not know the answer to your question, but I think the. answer is yes.
I would start with testing the blower motor, with a set of clip lead/jumper wires. I have been know to use an American Flyer train transformer to do power tests, MOST of them are 0-16 volts AC output.
George

[Dan B.]

Re: 1965 Rear Ventilation Motor In-operable

Jim, With the key on and front blower off you should have power to the rear blower. Try moving the switch lever on the blower all the way to the right by hand, that will give the rear blower full available battery power bypassing the resistor and you should see the blower motor turn. If the battery is a little low and you are trying to run the blower through the resistor it may not turn in the slow position. The next step would be a volt meter to test for power. In low or med position (first and second position) you should feel the resistor get HOT if it's getting power. Good luck, Dan

[James W.]

[Dan B.]

Re: 1965 Rear Ventilation Motor In-operable

You should be getting 12V at the brown wire, do you have a good ground for the test light and to the motor itself (check the black wire)? I'd try running 12V directly to the motor just to test it and see if it works bypassing the switch and car wiring. If so, trace the brown wire back to the front under the dash, check for continuity and make sure the connections are good.
Troubleshooting in order will eventually solve this for you. Good luck.

[James W.]

Re: 1965 Rear Ventilation Motor In-operable

Dan,

Ground is good, I verified power at the cigarette lighter and the power antenna using the same ground source when I check the rear blower switch connection at the dash fan switch. There is no power at the brown wire connection which when plugged into the switch would feed the rear vent motor.

My guess is it is the dash switch which is not available for sale.

James

You should be getting 12V at the brown wire, do you have a good ground for the test light and to the motor itself (check the black wire)? I'd try running 12V directly to the motor just to test it and see if it works bypassing the switch and car wiring. If so, trace the brown wire back to the front under the dash, check for continuity and make sure the connections are good.
Troubleshooting in order will eventually solve this for you. Good luck.

[Richard M.]

Re: 1965 Rear Ventilation Motor In-operable

James,

If the switch is the problem, you may want to consider opening it up to repair it.

Also, not sure if you have this but see attached from Dave Z. re rear blower info.

I also have another pdf from Dave Z. and Tim W. that may help but too big to upload. We're working on splitting it up to get to fit.

Edit.... Also attached below in 2 parts.

Rich

[Dan B.]

Re: 1965 Rear Ventilation Motor In-operable

Yes, like Rich says, these switches can be repaired. I took the rear switch apart at the blower on mine and modified it slightly so it moved easier when actuated by the cable. Could do the same in the front for sure if that is your problem. I also discovered some of the internal switch parts are interchangeable with some other non corvette switches of the era from the same manufacturer.

[Michael S.]

Re: 1965 Rear Ventilation Motor In-operable

@rich mozzetta, just read your post. very useful info. very nicely done. thank you.

[James W.]

Re: 1965 Rear Ventilation Motor In-operable

There is no power getting to the rear of the car, so it has to be in the front (dash) switch. No power at the brown wire for the rear vent fan motor that is connected to the front dash switch. the low, medium and high speeds work for the heater blower motor.

James

[Richard M.]

Re: 1965 Rear Ventilation Motor In-operable

There is no power getting to the rear of the car, so it has to be in the front (dash) switch. No power at the brown wire for the rear vent fan motor that is connected to the front dash switch. the low, medium and high speeds work for the heater blower motor.

James

James, The front dash switch is the one I'm suggesting you repair. If you remove it take some photos and maybe I/we can walk you through it. Looking at Daves pictures in the Part1a pdf I attached earlier pages 8-11,14,15. It looks quite easy to open up as there are 6? bendable tabs to get inside. It's likely some dirty contacts inside and a simple cleaning may work. You'd just have to be careful when it opens up to see the orientation of the parts and take lots of pictures.

I see they make a replacement type switch(w/AC) but it's not identical to original and has wiring mods. Looks like a relay is included for the rear blower on coupes.

Here Pricey too.

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[James W.]

Re: 1965 Rear Ventilation Motor In-operable

I won't change the switch if it requires a wiring reconfiguration. I am concerned about removing the original front switch a digging into it only to find out it is not repairable when the front fan switch functions perfectly. I'd like for the rear vent fan to function for flight judging, but as I see it, it would only be a partial point deduction (+/-7) for that particular part of the vent system not working.

James

James, The front dash switch is the one I'm suggesting you repair. If you remove it take some photos and maybe I/we can walk you through it. Looking at Daves pictures in the Part1a pdf I attached earlier pages 8-11,14,15. It looks quite easy to open up as there are 6? bendable tabs to get inside. It's likely some dirty contacts inside and a simple cleaning may work. You'd just have to be careful when it opens up to see the orientation of the parts and take lots of pictures.

I see they make a replacement type switch(w/AC) but it's not identical to original and has wiring mods. Looks like a relay is included for the rear blower on coupes.

Here Pricey too.

[ATTACH=CONFIG]97941[/ATTACH]

[Don H.]

Re: 1965 Rear Ventilation Motor In-operable

James, If you don't replace the switch I would put power to the lead from the fan switch to the vent so it works. Then the only thing wrong is it does not shut off when the fan is on. Depending on the judge doing ops, they might not even catch it. Good luck, Don H.

[Mark M.]

Re: 1965 Rear Ventilation Motor In-operable

James, I'm not sure but that switch may be the same on all midyears. 1974 GM parts book shows 3864600 switch for 63-64 non(c.a.c.)and 65-67. There's a few used ones on e-bay now and the pictures show 5 terminals. I could get the switch from the 65 conv. I'm doing now as it's out of the car and check the terminals and functions.

[James W.]

Re: 1965 Rear Ventilation Motor In-operable

SUCCESS!!!

Today I made a jumper power wire, disconnected the brown wire connector that feeds power from the dash fan switch to the rear bower vent motor, connected the jumper wire to the brown wire connector for the front fan switch and the other end to the power terminal on the firewall fuse panel. I turned on the battery disconnect switch and the rear blower vent motor worked on all three speeds when moving the rear vent cable, so that determined that the rear vent blower motor works and the problem is in the front heater vent fan switch.

With some reluctance, I pulled the switch out of the dash, match marked it on two sides before disassembly and carefully took it apart. I found the all of the contacts were dirty so I cleaned them with contact cleaner and a cotton swab then lightly sanded them with some crocus cloth, then cleaned them again with contact cleaner. I carefully reassembled the outer cover using the match marks and reinstalled the switch in the dash and reconnected the terminal connectors. I had my son standing at the battery cut-off switch to turn it on and off at the first site of any smoke. I turned the key on to accessary and tested the front vent fan switch which worked on all three speeds. I turned the front switch to the off position and pulled the rear bower vent fan switch cable and it now works on all three speeds!

Thanks to both Rich and Dan for the information, great PDF's and encouragement to dive in and see if the switch could be repaired.


Best Regards,

James West