I made a video see if it helps explaining myself. I forgot to mention that I charged the battery last night and brought a jump starter in case the battery was low.

 

You swapped with #88 (rap)relay? Does the rap work? SWAP with a known working relay like #72 controls the windshield wipers, do they work?

 

After you verified relay good, go back to the tank and check connection/contacts to the MU1473

 

It's messing with me 🤦‍♂️. I had swapped them and it didn't work. The only thing that has happened is the relay swap in the video, towing the hummer back home, then swapping again as suggested and it turned on. Is there really a clear repair, it doesn't seem like a reliable part of the vehicle.

https://youtube.com/shorts/btWMWLg4JP8?feature=share

 

Do the windshield wipers work after the swap?

 

Yes, the wipers worked after the relay swap.

 

Time to open a can & clean relay/fuse block contacts(BATTERY DISCONNECTED).