I own a 1972 LT-1, and the wiper motor has never worked since I purchased the car. I initially assumed it was a bad motor, so I recently had it professionally rebuilt by D&M Restorations. Unfortunately, after reinstalling it, the wipers still won’t operate.
Before reaching back out to D&M (who have been excellent to work with over the years), I want to make sure I’m not missing something on my end — particularly with the wiring.
Here’s what I’m working with:

• Three-prong connector
• Single red wire connector
• Separate ground

I can get power to the three wires depending on the switch position, and I’m attempting to bench test the motor to rule it out completely. Given D&M’s track record, I’m inclined to believe the issue is somewhere in the wiring rather than the motor itself.
The switch does open the vacuum door, but it will not turn on the wipers.
Does anyone have a wiring diagram for a ’72 LT-1 or suggestions on how best to troubleshoot this setup?

Any guidance would be greatly appreciated.

 

I'm watching to get ideas for one of mine.
Have you made sure the motor is grounded?

 

I have had issues with these assembly's with the Relay switch assembly sticking with age leaving the circuit in the open position, non operable. WD-40 often works. The relay is what places the wiper blades in the Park position.

 

 

I resolved the issue today. After tracing the red/white power wires from the fuse box to the vacuum switch, I confirmed they had power—but only when the switch was engaged fully. The switch uses an adjustable bolt and keeper nut to activate the plunger. I found the bolt wasn’t pushing the switch firmly enough to allow power to pass through to the pump’s red/white wire. After adjusting the bolt to ensure solid contact with the switch, power flowed properly and the wiper motor is now working as it should.

 

That's good news. Thanks for reporting back as it might help somebody in the future. I always heard back in the day that the wiper door is hard to keep adjusted properly also.