Windshield wipers do not work

Okay. We need to do a couple things. First take a look at the wiring diagram. We need to check for power at number 1 with the key in the run position.

Then we need to turn the wiper switch on and find out if the GEM is grounding the relay to close the relay. You do this by putting your red meter lead on positive battery terminal, then remove the relay and put the black lead at number 2. The meter should read 12 volts. If it is then the GEM is grounding the relay correctly.

If this all checks out then you know the relay is getting grounded so jump number 1 to number 3. If the wipers come on your relay has failed.

Let me know what you find and we can go from there. Thanks

Sorry. You listed yourself as a mechanic so I didn't explain that more as I made an assumption that you had experience with wiring diagrams. We need to remove the relay and check the voltage as described as above.

Here is a guide that will help in explaining this:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit