Intermittent Windshield Wiper issues, 1989 325i w/ M50

[CMG]

I have a few minor electrical gremlins I am trying to sort out. One of them is windshield wiper stalk has intermittent issues with sometimes not working. Most of the time it works fine but sometimes none of the functions work, and it can come and go while driving. I checked fuses and relay and jumped pins and used a multimeter to confirm things in fuse box are ok. I checked the grounds under dashboard and they are tight. Anything else I can check? Is it possible the stalk itself could come and go like that?

[packratbimmer]

There are the wiper motor circuit board and the large/long cuboid relay.

[CMG]

I assume you mean the rectangular relay in fuse box. I tested that and worked at the time. I am not aware of the wiper motor circuit board. My issue comes and goes and involves both sprayer and wipers not working. It comes and goes randomly, but wipers have never got stuck in up position. The relay or power/ground seems to be the issue. I assumed that relays usually get stuck in one position, as opposed to intermittently coming and going.

[dnguyen1963]

My old relay got hot for some reasons and the wiper would not work. Changed the relay and everything was fine.

[Tzantushka]

Yeah, I would start with the relay and if that checks-out the actual wiper motor can get gummed up.

[CMG]

Yeah all the basic tests and checks of everything came back negative. It's not the wiper motors cuz if that was the case I could spray cleaner onto windshield and wipers would not work. It always happens together. Intermittently I have electrical gremlins that occur every few months, car is driven regularly. I think at some point I should just do a thorough check of the fusebox, harness, and under dash wiring. Since it's a swapped car it obviously had changes to the wiring and grounds. I'm gonna start with fusebox cuz I have the fuse for power mirrors that sometimes burns out. I just did some basic searching and looks like fuse box replacement is a PITA, but how hard is it just to flip it over to inspect and check wiring underneath?

[CMG]

So I think I figured out most likely was the issue. I previously tested and checked everything but did not have to replace anything. Was working fine for months then yesterday out of the blue wipers and sprayer stopped working. Checked fuse box and fuse was good not blown, but when I looked closely noticed that the filament inside looked like it had a line across it. BTW I only use the original oem fuses with the slot on top you can look down at filament, and the fuses are all over 20 years old. I swapped out the fuse and solved the problem. I'm guessing that over time the old fuses can have the filament degrade or even crack, so visually they look good, but they may not be able to conduct full amps all the time.