trying to check wiper motor relay.

[MIKe30]

just picked up an 90 325is with no windshield wiping capabilities. when you flip the wiper stalk, nothing happens, no extra noises nothing. i want to check to see if it is my relay before trying to replace the motor (which i hear is a nice royal pita).

I've read the long rectangular relay on the passenger side is the one that controls the wipers, and i have another e30 to swap the relay from to check it - but it is a 91 318is, and the part number on the relay is different. bad idea to try and swap it or no? worst scenario if i try it is...?

thanks for the input.

-mike



edit:

part # for 318is - 1 386 978 stamped in white ink on side - 012 11SB
part # for 9032is - 1 374 613.2 stamped in white ink on side - 92011 SB

318is relay also has a brown circle on the bottom side. otherwise the rest of the relays match up (all pins labeled same numbers 53b, 53, 15, 31, etc etc)

[MIKe30]

if both relays control the same things on both cars, then they should be interchangable. at least thats my thought process... am i wrong on this? also the second thing is i'm not sure if they both control the exact same functions.

hope someone has some insight.