Central locks activating if headlights on

[Winterhawk]

We have a base model 97 850 wagon. Ours did not have keyless entry (no control unit behind glove box).
We just got a used control unit and keyfob from a 96 855R. I installed the unit, programmed the fob via the key on 5 time method.
The fob works, it locks and unlocks the doors, however if the headlights are on (key on or car running) the locks are engaging on their own. They don't fully unlock, they just pop up a little, but make the same noise as locking/ unlocking via the key.

I pulled the battery from the remote to verify we didn't have some sort of rouge signal but when the headlights are turned on it persists. Do we have a faulty control unit?

Other thoughts?

Justin

[rspi]

There may be a different relay for under the dash for cars without the control box. Check into that and you may need to swap out that relay from the donor car.