Bx Blower, proper fix???

Niek · Post by **Niek** » 21 Sep 2005, 03:24

Hello guys,
I know this has been discussed numerous times but I can't really find an answer.
I need a proper fix for a Bx blower, ours breaks down about once a year, I then take it apart completely, clean everything including the brushes and it works again for about a year... Very frustrating!
Does anyone recognise this and have any sort of tips?
The whole thing might also be a little less annoying if the max speed relay would work. I've done the mod to the pcb in the dash but that didn't do it. My relay is definatly not mounted on the steering bracket (LHD car). Are there any other places it could be or is it possible to have a Bx that doesn't have this relay altogether??? (I do have the green wire coming out of the +12v wire at the motor, and it is linked to terminal 4 of the dash connector.
Thanks,
Niek

fastandfurryous · Post by **fastandfurryous** » 21 Sep 2005, 05:51

It could be something like a shorted winding in your motor causing excessive sparking/arcing between the brushes and commutator. How clean does it look when you take it apart each year? If this is the problem, then the easiest/cheapest option would be a second-hand motor.
I've had this happen with a wiper motor before. Blue arcs all over the place, and a burned mess. Cleaned up and worked again for about a week.

citronut · Post by **citronut** » 21 Sep 2005, 14:12

the speed control is the pcb behind heater controls and the resitor in the rear of the fan box,99% of the time replacing the resitor fixes the prob,also the contacts in the dial on earlier pcbs used to burn out when the resitor failed,on the later pcbs this did not seem to happen as much as they moded the copper contacts
regards malcolm

AndersDK · Post by **AndersDK** » 21 Sep 2005, 14:58

Malcolm there is no resistor in the speed control module on later models. It's a Power Transistor circuit [;)]

tomsheppard · Post by **tomsheppard** » 21 Sep 2005, 23:09

As the originator of the infamous modification, the suspect boards are those marked ELEDASA. Others should not need the mod. Check the middle pin on the pcb is earthed. Often there is a break in the wiring to the fusebox. If the earth is suspect, I take the group of five wires
(three green and two brown) which are accessible by removing the glovebox and joining the two browns together before taking an earth wire from there to the bolt at the back of the centre console. A common fault is the rivet that holds the transistor to the module in the fan. Drill it out and replace it with a brass screw, a nut and a shake proof washer. If your motor has new brushes and fails often, then I suspect it is shorted within so get another from a scrapper. To activate the full speed relay, earth the second pin from the left on the controller board.

citronut · Post by **citronut** » 21 Sep 2005, 23:22

anders that may be so but GSF still call it a fan resitor,and it is part of the speed control system shuerly
much regards malcolm

citronut · Post by **citronut** » 21 Sep 2005, 23:25

why go to all the bother of moding this when it is usuly fixed by replacing the "resistor"ha ha or module what ever you want to call it
regards malcolm

Niek · Post by **Niek** » 22 Sep 2005, 02:46

@ fastandfurryous: It looks clean when I take it apart, I think it's usually caused by bad contact due to corrosion on the resistor board thing that lives in the blower housing.
@ Tomsheppard: I'll try the further mods, brass bolt, and the wireing check.
If the relay is not on the steering bracket (LHD) where else could it be, or should I just replace the whole wireing and ass a relay to it???
Cheers,
Niek

Niek · Post by **Niek** » 26 Sep 2005, 01:48

Hi Guys,
I fixed the blower, replaced the rivets with bolts and cleaned everything again. Works.
Our Bx definetly didn't have the max speed relay, this means that the wireing loom was changed near the end of production (our's is Nov. 1992). Traced the wireing needed according to the manual and added a relay. I had already done the mod to the pcb (ELEDASA type) and everything works now including the max speed !!
Thanks alot.