Check the Fuse/Relay block. There are quite a few burnt blocks in the junk yards. I can't remember which rely socket burnt up on my daughters 94 940. The cause wasn't the connection from the relay to the socket but rather the hot wire connected to the short buss below the socket. I spliced in a second wire to double feed that bus and replaced the socket too. Her car’s problem sent me on a quest at the local u pics. I must have pulled out a dozen blocks and turned them over. I saw several overheated connections on the under side. If one of the feeds fails several things stop working. When you replaced the relay you probably disturbed the connection enough to make things work for a while.
Now the clincher .. According to my copy TP 3904202 section 3 (39) 1994 940 Wiring Diagrams; Fuses 1, 2, 3, 4, 5, share a common feed from the battery.
1- Fuel Pump (LH) and Fuel System
2- Hazard Lights, Door Locks
3- Power Seats
4- Brake Lights, Shift Lock
5- Clock, Vanity, Trunk, Interior, Radio, Door Lights
6- Electronic Climate Control
Good Luck

Al
Had 1-245D, 1-240D, 1-240, 3-1994 940s
Have 1993 945 with ~ 400K mi
Looking for a “Young” 94 or 95 945T