top motor question for the electric guru's

[72 machrag]

My 72 top motor is giving me trouble. First I was burning out the switch every couple times I used it. So I hooked up relays in the circuit and that solved the switch problem.Now the motor stopped working altogether.This is what I have done so far.
I resealed the motor last year and found it had fluid in the motor part so I cleaned everything with contact cleaner.
When I rebuilt the engine I installed a 120 amp alternator.
The guy that installed my top said to make sure the engine is running when I put the top up and down.I think there are too many amps going to the top motor this way.
What do you think?

[Rare Pony]

Never had any problems with my convertible top on my 73 Convertible, but you should have a circuit breaker at the starter solonoid that is for the convertible top. Some heavily optioned Mach 1's have it too for some accessories. Here are some pictures:

[1969jimmach]

My 72 top motor is giving me trouble. First I was burning out the switch every couple times I used it. So I hooked up relays in the circuit and that solved the switch problem.Now the motor stopped working altogether.This is what I have done so far.
I resealed the motor last year and found it had fluid in the motor part so I cleaned everything with contact cleaner.
When I rebuilt the engine I installed a 120 amp alternator.
The guy that installed my top said to make sure the engine is running when I put the top up and down.I think there are too many amps going to the top motor this way.
What do you think?

I would check it with an amp clamp see what it is pulling also check the ground circuit most electrical issues start with a dirty or corroded ground circuit.

[Oztrailer]

Does the motor have bearings or bushes? The fluid may have been grease from gearbox. I am assuming it has a gearbox. It might have dried up all the grease in the gearbox? When you cleaned it all out with contact cleaner you may have taken away the lubrication from the bearing/bush areas in the motor and it might be siezed now?

[72 machrag]

Thanks for the replies. The grounds are all new. Cleaned all connections and service manual says circuit breaker is in the motor. I will have to pull the motor and open it to see if seized. Then I can check amp draw.Does anyone know the resistance reading for a good armature?
I have never seen a c.b. in that location before.Great pics. I'll have to do more research.
Anyone heard anything about having the car running during top operation?


Thanks, Ron.

[Oztrailer]

The only reason to have your engine running would be to reduce the load on your battery. While the engine is running it is helping to charge the battery. Some electric motors can have a large current draw while running.

[chutsonjr@yahoo.com]

Have you checked to see if any of the moving parts are in a bind . If the top doe,s not move freely with the motor atached . Try it by hand with out the motor hocked up . Do this a few times from down all the way to fully up and locked in to the window frame . Because you do have some ajustments on both sides to line up right also . If something has moved when you unhock the motor it could have been in a bind all along . If the motor isn,t the same size as what was first there you could be short or long . Some times a little oil could go a long ways . C . L .