Let's see, the aircraft in question is a 1968? Is that correct Robert? Tony, are you referring to the electric power pack? The 68 is gear pump on the accessory case of the front engine. Just to keep things straight let's make sure which aircraft model we are troubleshooting. It sounds like the main gear switches are not functioning properly or have a short, crack, etc. That's usually the case as Hank pointed out.
I would not use the E pump for the testing while on jacks. The E pump is not for continuous use. I agree that it is a good idea to at least lower the gear once in a while with the E pump but retracting it will not give you the same operation as the gear driven pump on the engine. You don't need a mule to do this function. Contact Owen Bell and he has a socket bit that is the female to the gear pump. Simply remove the pump from the front engine and use an electric powered drill to transition the gear. It works great. And you will own the tool for the rest of the time to swing your gear for each annual. It's well worth the money.
See my video on you tube
http://www.337skymaster.com/messages...ead.php?t=2656