65/66 convertible switch blowing out?

[Impalabricker]

I know this sub forum stops at 65, but may I ask a 66 question since it uses 65 parts? I have a 66 Rag top that has blown 2 aftermarket switches already due to excessive current draw and switch heating. is this normal? I recently bought a NOS 65/66 switch for it and installed it but Im scared to use the switch since I paid almost $200 for it! What are you all using to power your tops? Someone suggested a relay..? Would that work, why do these draw such high current?

 

[Jim Sullivan]

I haven't looked at a wiring diagram, but would think there should be a circuit breaker in the system to prevent damage. There may also be a relay in the system which may be bad or have been removed and bypassed? If there wasn't a relay in the system from the factory, and the switch is designed to carry the load from a properly functioning pump, then there is probably an issue with the pump causing the switch to burn out. You may have to bypass the switch with a fused jumper and an amp gauge to verify if the draw is in or out of spec.

 

[RussC]

Jim is right there should be a circuit breaker. Earlier models are located near or behind the driver's kick panel. The overload could be a number of things...bad pump...binding top rack...I would check the wiring to the pump for a short to ground. I had one I couldn't figure out so I installed a relay at the pump and used the switch to operate the relay...problem solved

 

[63impalass409]

There is a circuit breaker bolted up above the driver kick panel where the power feed from horn relay join and for my 65 convertible it uses the same breaker as my power windows. My top motor and cylinders are new so no problems so far knock on wood!!!

 

[fsc66]

As already stated, there is a 30 amp circuit breaker above the driver's side kick panel that is used for the power top, power seat and power windows where applicable, see attached pic. You need to make sure the circuit breaker is there and if so, that the switch runs to it. You'll find more detailed information in the assembly manual. If you don't have an assembly manual, we have a PDF of it on the Full Size Chev, site, here is the link: https://toms427impala.info/CT/66assemblymanual.pdf See page12 D1, D2, D3 and D4. Here is the GM part number for the breaker in case you need one, pretty readily available but I'm betting it's there:
Breaker GM 4850166
Paul

 

[pvs409]

Here is where the circuit breaker is installed on 61 to 64 Chevy's. I would think your 65 is similar.
The picture is a 62 SS convertible with power top connection & power windows. The wiring harness from the top motor connects to this circuit breaker as does the power windows, and SS console wiring.


The yellow wire goes to the firewall and then to the starter (using a red wire to the starter from the firewall).
Paul

 

[Junky]

I'm betting on it being a bad power top motor. The only way to know for certain is to check the amperage draw with a meter. It also could be the top pistons binding or having rust on them, but that usually only takes out the piston seals. If you were using cheap Chinese switches, that could definitely be a problem. A good switch should cause the circuit breaker to trip before it was destroyed. If you power top system is original, and it still has brake fluid in it, then you will need to disassemble it, and check for rust in the impeller and check balls. Just be careful not to pull the armature up, because it is a real bear of a job to get it back in place with the brushes, etc.. If you get everything cleaned in the pump, then remove the cylinders and lines, blow them out (away from the car), and refill everything with Dextron transmission fluid. If you don't want to do all this work, then you can purchase all new parts. Ask Paul (PVS409) where to purchase them.

 

[Impalabricker]

Thanks for all the great information. Im gonna pull the kick panel off and see what's in there. I guess there are lots of possibilities. Does anyone know how many amps the motor should be pulling? I recently replaced a hydraulic line after purchasing the car and I used the bleeder pump found on ebay to re-fill and purge the system of air. Im not quite sure I have enough fluid in the lines as the top sometimes struggles to come back up after going down. Would lack of fluid cause the motor to work extra hard thus drawing excessive amperage?

 

[Don Jacks]

No but it can cause damage to the pump motor.That motor shouldn't draw more than about 15 amps.

 

[63impalass409]

My breaker is way above kick panel not behind it almost have to be a monkey and hang upside under steering column to get to it! Doesn't help I also have all the factory cruise control crap in the way! 1st world problems right?

 

[fsc66]

I also believe the circuit breaker is above the kick panel. You'll have to look up above the kick panel and I think you'll see it. Also grab hold of the power feed from the power top switch and carefully follow it and hopefully it will lead you to the circuit breaker. Paul

 

[DonSSDD]

If you replaced any lines or fluid in the top system , you could have low fluid or air in the lines, which would make the pump work harder and not work properly.