Hello!
I have a 1999 BMW 523i E39 (bad choice for reliability, I know, I'm currently looking for a replacement) that I have an issue with. I was out driving and were passing a semi at about 120 km/h (~75 mph) in a downpour and my wipers stopped working completely. The car has three modes (rain sensor, medium and fast) and I can manually wipe once by pulling the stalk down. Neither of these modes worked at all. I managed to pull off of the main road and stop and about at the same time the rain calmed down a bit and then the wipers started working again. After being unable to figure anything out right then and there I kept driving and during my three hour trip I drove through a few rainstorms and each time the same thing would happen, the wipers stopped working until the rain calmed down again.
I've scanned the car for codes but there were no codes stored at all. I've also looked over all the cowling and there's nothing broken, cracked, loose etc allowing water to seep in and I doubt that there are connections getting wet causing the issue since they start working again as soon as the rain calms down even though I'm at a standstill not allowing water to flow away by the wind etc. I'm not sure though as I'm not experienced with this, it's just what I think.
Do anyone here have any tips on what the issue might be, what I could try to diagnose it etc?
Thanks in advance!
If the wiper motor is good and the problem is in the control module(s) I would be very tempted on a car that old to just bypass whole electronics mess and hot-wire the wiper motor with a simple switch.
I’ll probably do that if that’s the issue as I don’t want to do more than absolutely necessary seeing as I plan on replacing the car as soon as I decide what I want to replace it with
The wiper motors might be faulty. Check to make sure you get power at the motors.
In what way would it be faulty in that case seeing as it works when it's not raining too heavily? And I'd assume they get power for the same reason. I'm not saying it's not the case, just trying to understand the circumstances
If the motor is weak, you may have intermittent situation. Maybe when it rains heavily, it does not have snow the power to do the job.
That sounds logical. Do you know any good ways to test this?
This might help:
https://youtu.be/7EliY2Hwj0E
Thanks! I’ll check that video tomorrow
My 2 cents on an electrical intermittent are bet on the wiper motor ground. The power feeds are usually a nicely insulated wires with snap together connectors, but the grounds are just terminals screwed into the sheet metal on many cars, and they get loose and/or corroded, especially after 22 years.
That definitely sounds like a possibility I didn’t think of. I’ll take the cowel off and look at it
The water from the heavy rain seems to be interrupting the grounding circuit like Glen_stet said. Check the motor grounds for looseness and corrosion.
That definitely sounds like a possibility I didn’t think of. I’ll take the cowel off and look at it