I mentioned heat because it was significantly hotter here in RI when it failed to work. When I resumed troubleshooting and found it was working again, the only difference I noted was much cooler air temperature. Nothing else changed.
By without a load, I meant with an empty cab - no people or objects that might trip an overload circuit. When the problem was happening, it would not travel down more than the 6 inches with or without a load.
Thanks for your interest.
