- Do It Yourself Auto Repair
The Chevrolet Corvair Convertible: How to troubleshoot its problems
When your top fails to lower or raise
There may be a day when you want to lower or raise your top in a 65-69 model and either nothing happens or the top moves a little and stops. After you try several times, you come to the realization it broke. As long as there is no immediate rain, don’t worry.
While the electric motor behind the rear seat is basic, it is the source that raises and lowers the top. The GM manuals do not tell you a lot about them. Generally, it is unlikely that both drive cables attaching are broken. The cable is very strong and well protected, odds are it has something to do with the switch connections being corroded, the switch is bad, or the motor after so many years has burned out. The motor is hard to find, Clarks has them for $325! A switch can be found for $56. Another place is near the motor and the relay area where electrical connections happen. Each drive cable from the motor also connects to the right and left side behind the seat. The motor turns them which raise and lower the top. If the cables are well connected in all areas, discount this area as a problem.
If you need to raise or lower the top and the motor fails, simply disconnect the two cable drives going into the motor. Now raise or lower manually-it is heavy! Lowering can be done fairly easy with one person, raising is done best with two people.
Things to Troubleshoot
The motor and drive cables
1. Remove the two screws holding it on and examine for any obvious bad connections or other issues. The top can be removed and one can clean the three contact poles of the switch.
2. Disconnect the wiring going to the motor. Disconnect the two drive cables.
3. Attach a temporary ground wire from the motor base to the negative post of the battery.
4. Run another long wire from the positive post on the battery and touch it to the wires leading into the motor.
If the motor operates and the cables are spinning then it's not the motor or cables. It is not likely both drive units would go bad at once. Consider the switch or power to it (should be 12V).
If the cables don't spin and the motor doesn't sound like it working then it's probably the electric motor or gear drive attached to the motor.
5. Open up the Gear Housing Cover (three screws). Examine the gears, make sure teeth are good and are well lubricated. If you find chips or pieces, replace the gear.
6. See if the top will move up and down by hand (it will be stiff but should move smoothly). This should isolate the problem to the motor/gearbox or top mechanism. Things to check: all electrical connections, burnt contacts in the relay, old, dried, grease in the gearbox. Take good care of the gearbox, it is expensive to replace. Check both ends of each of the drive cables by unscrewing the ends. While you have them out, re-lubricate them.
Using a Voltage meter, ground the black wire. Turn on ignition. Using the red probe and pushing the switch forward (to lower) touch each connection of the switch. The meter should be 12V. Other connections may read differently. Now do the same except pull the switch (to raise). Touch the probe on the connections for a 12V reading.
Alternatively, bypass the switch and use a jumper wire from a 12V source like the cigarette lighter and touch the wire of the switch that lowers the top. If the top lowers or motor operates, the top connector to switch is OK, but the actual switch is bad.If the switch is bad, the good news is that you can find them and easily fix. If the motor, odds are you will have to have a manual top for some time until you find it.