I have many relays, sensors and electrical parts from various 914 parts cars.

My question is if these test out as being good, are they ok to use? Just asking if it might be better to buy new stuff rather than use 40year old electronics that would fail soon after being put back to use.

Any thoughts or experience with this would be appreciated .

Thank you

A lot depends on how and where they were stored. Rust is bad especially on things like electromechanical relays.

If it is something really hard to get to or critical to safety you may want to go with new. Otherwise, probably fine to use them.

Yes, used parts can fail, but they are "solid state", so test them, and carry some spares.

Buy a pack of red, white and blue fuses from the eBay vendor that sells 20 of each + free ship for $10. Replace them all including the ones on the relay board in the engine compartment. Keep the extras in the glove box. You can't go wrong with new fuses vs old.

I am not as worried about the solid state stuff as I am the relays, switches, motors.

How robust is some of this stuff? Sure it tests out on the bench and works now but after
It's installed back in the car and heats up wondering about the failure rate.

Thanks

I would use them and carry spares. Hell, even new parts fail.

The quality of the old relays is better than new ones. Just carry spares.

The "solid state" only applies to the ECU and a couple other items (tach, flasher relay, etc.). The biggest issue for this stuff is capacitor failure. The caps can dry out over time and fail.