Hello So my windscreen wipers can be only used on max speed and only this speed. Was time when was working few seconds on mid speed but after 2-3 seconds stopped in the middle of the windscreen. Atm only max available, fuses are fine- checked, cant find relay or relay module in my car. Pulled out today half of the dash and didnt find anything. Any ideas where it could be? Thanks
More than one similar thread has ended up finding wear of the low-speed brushes inside the wiper motor. I had a different experience, where I lost my wipers completely (nothing on low or high) and fixed it completely by pulling the wiper fuse and rubbing its legs with a pencil eraser and putting it back. But that's not likely to be the issue here, if the wipers do work on one speed, just not on the other.
Yep; most likely wiper motor or switch. Don't know what you were expecting to find by ripping your dash apart????? Replace whichever one is cheapest and go from there. Don't know if you have access to junk yards out there; but that would be the cheapest route. Good Luck
Maybe was expecting have relay control unit same as says diagram schematic unfortunately in my case BCM does relay function , relays are first in line of fault, then might be something else, I might have relay on switch module itself as well. Control unit found for 10 quid so cheapest option so far, motor 150 up scrap yard 10 days waiting.
The wiper motor has carbon brushes that wear out as it turns. They end up commonly being the cause in posts around here. Haven't seen as many (any?) where the switch was at fault, but I guess I'd never say never.
But there is one crown with brushes they provide connection to rotor and signal is usually controlled by relay or in my case BCM, there shouldn't be such archaic method with 1 brush for every speed ...or they are not that smart, so replaced brush should fix the issue.
Does gen 4 even have wiper relays? I just have a gen 3 diagram to look at, and gen 3 doesn't; its steering column switch is wired right to the motor.
Yes minimum 2 versions are available so far from my research. One has separate relay control unit And one with integrated relay into swith from what I can see it might be mine case. Its wired directly to motor but it must have driver so presume it might comes with relay integrated into motor itself as well in some versions. It's really misleading when you are reading diagrams and then realised that there is more than this. Takes time but i think im closer than was just dont have time to dismantle swith and have a look what relay model have here.
Most Japanese cars I've dealt with, the relays are usually in one of the fuse blocks, closest to the motor in question. They're usually not just dangling on the wiring harness like American cars. I haven't looked up the wiring diagram on a gen4, haven't had a problem. I did look at door switch diagrams to possibly hook up an improvised tremor switch with an on-off relay - but that's as far as I got.
As you can see there is many options, those you are pointing are those old type one relay in fuse box usually under the hood, mine has 2 relay boxes and one module for cooling fan under the dash in place extremely hard to reach. But wiper motor must have driver somewhere, I couldn't find anywhere took me 50min disassembly of the dash and 30min to assemble it, could go with first feelings that switch might have it before taking out dash. Its really small and compact in size to be honest, everything is soldered so quite difficult to reach and check it, amayama has 2 types of those switches for sale just in case.
Make the contacts in the steering column switch robust enough, and you can eliminate some extra wires and added relays. Seems to be the route Toyota chose in gen 3. I wouldn't know if they went back to relays in gen 4 for any reason. Even the intermittent-wiper timer for gen 3 is just integrated into the column switch. (The front one. The rear one is integrated into the rear wiper assembly!) Again, that's for gen 3 though.
