Thank you for the replies.This is the older solenoid like the pictures in the second reply.
the resistance check produces no reading on the tester.It just stays at 1,which is where it is before testing.I think a new one is in order.I seen them on Ebay at $23.I shall attempt to find a local source first.
Try hooking 12 volts to the two small wires and see if the solenoid snaps when you make contact. If it does, you should be able to renew the internal contacts. The center contactor bar can be removed and turned upside down to present a new surface. The two battery contacts can be removed, dressed and positions swapped. That should give you another few years of use.
I have not been able to stay on this project consistently timewise.The Solenoid on this 1981 GL500 is similar to the second one pictured but not identical.The metal "cup" cannot be removed from the top which is plastic.There are not 2 wires as in picture two.
The resistance readout does not change from the 1 when read between g/r and y/r wires.
When the start button is pressed the solenoid clicks but the output voltage to the "motor" wire (starter) reads about .25 volts.
The starter works fine when the solenoid is bypassed.
I guess the solenoid is therefore defective.
Thank you all for your reading this and being patient,Mike