OAP Heater bypass valve not working?

[Steven Lobel]

No idea what happened, but this time out the heater servo valve quit working. Could not get hot air blowing.
Superlite GT-R
Vintage Air slimline
OAP 50-1555 electronic valve.


Troubleshooting:
Test that switch/dial is getting power- done. And grounded.

Now what?

I ordered a backup valve in case of part failure. It is mounted on firewall under motor.

 

[Tom]

test positive voltage at servo lead
test continuity of servo
test ground lead