I've just spent the winter trouble shooting/replacing/repairing my 1971 ls5 after sitting in storage for 5 years. The clutch assembly has been replaced, 4 speed Muncie rebuilt, leaking engine gaskets replaced, oil pump replaced, starter armature cleaned/brushes replaced & tested for function, battery replaced, smaller diameter steering wheel installed, horn button kit installed, oil/filter changed, and other routine maintenance stuff. All has been reassembled and engine has been cranked over but not started. What I notice/hear is a "clicking" sound immediately heard when both cables are hooked up to battery. The clicking sounds exactly like a solenoid trying to engage but engine cranks beautifully when key is turned in ignition switch to the start position. Clicking sound occurs even when not engaging the starter switch. Two things come to mind: The adjustments on both the Neutral Safety Switch located on the clutch pedals may have changed with the installation of an all new pressure plate, clutch disk, and throw out bearing, and/or the backup switch located on the side of the 4 speed transmission. May be one or both need readjusting? May be neither. Any suggestions will be greatly appreciated as the resolution of this "headache" will complete my preparation to ready her for street driving to events, shows, and pure pleasure.

 

Get a helper to connect the cables while you look for the source of the noise.
What you are describing sounds like a relay not a switch.
Dont forget to look at the relay in the jack storage compartment if you have a factory alarm.

 

If you want to do it yourself, remove the fuses in the fuse box and install them one at a time to see what circuit the relay is on. This will help narrow down the source. Good luck. Jerry