Blower / heater mystery

[Morgenster]

Hi guys and gal,

My blower only blows on 1 and 4
I'm wondering if my blower resistance is really the culprit because sometimes 2 and 3 work, but only if the knob is in that position when I turn on ignition. Anyone know how the knob itself functions?

Also, there seems to be heating at the passenger side even with both knobs (driver/passenger) set to cold. Is there a separate valve for the passenger's side that's stuck somewhere?

[BillionPa]

the problem is the sword (i think)

[shogun]

http://www.bmwe34.net/e34main/mainte...ical/sword.htm

Maybe the know is not working. On my E32 it is a thumbwheel. Check that also.

[joshua43214]

It could be the switch or the resistor, its pretty straightforward to test for voltage at the resistor for each fan speed.

There is 1 water valve that has separate controls for passenger and driver.

This is very well covered ground here, do a search of the forum for lots and lots of info

[Morgenster]

Found the resistor pack after a long and frustrating hunt. Mine's on the passenger side and isn't blue but brown...
It's a pretty open circuit with three spring wires and 4 connectors at the plug. There was nothing visibly wrong but I didn't get to test resistance..
When removed completely, the fan will only blow in position 4, so the resistor pack takes up 1, 2 and 3.
The pack looks very simple. I couldn't see who manufactured it though.
Anyone have an idea who made this and what resistance values should be read from it?

As for the heater valve: I'm prett sure now that it's the valve stuck open. The website Shogun mentioned speaks of valves stuck shut, but I guess it works both ways. I'm going to give the gentle hammertap trick a try and pray to God that it'll fix the problem cause I really don't feel like shelling out the money for a coolant drain and fill + parts for something this simple.

[genphreak]

Found the resistor pack after a long and frustrating hunt. Mine's on the passenger side and isn't blue but brown...
It's a pretty open circuit with three spring wires and 4 connectors at the plug. There was nothing visibly wrong but I didn't get to test resistance..
When removed completely, the fan will only blow in position 4, so the resistor pack takes up 1, 2 and 3.
The pack looks very simple. I couldn't see who manufactured it though.
Anyone have an idea who made this and what resistance values should be read from it?

As for the heater valve: I'm prett sure now that it's the valve stuck open. The website Shogun mentioned speaks of valves stuck shut, but I guess it works both ways. I'm going to give the gentle hammertap trick a try and pray to God that it'll fix the problem cause I really don't feel like shelling out the money for a coolant drain and fill + parts for something this simple.

The valve sticks from gunk, so beware your cooling system may have (or be) gnking up- a good flush through the heater core and valves (cycling open close open close) plus of course changing coolant with a by the book block flush, radiator removal flush etc. may be worth doing... it is pretty much a replacement item- cheap to buy new at $110 odd. A lot of people fix the resistor packs (a lot of people call them swords) by resoldering the power transistors, though others have to replace them. I'd resolder and reconnect to see. The joints dry up and crack from the constant heating/cooling I think. Careful isnpection of the PCB is a must at least. nick

[Morgenster]

The valve sticks from gunk, so beware your cooling system may have (or be) gnking up- a good flush through the heater core and valves (cycling open close open close) plus of course changing coolant with a by the book block flush, radiator removal flush etc. may be worth doing... it is pretty much a replacement item- cheap to buy new at $110 odd. A lot of people fix the resistor packs (a lot of people call them swords) by resoldering the power transistors, though others have to replace them. I'd resolder and reconnect to see. The joints dry up and crack from the constant heating/cooling I think. Careful isnpection of the PCB is a must at least. nick

What is PCB?
I'm thinking that next time I take it out I will test resistance on all terminals and solder if needed. The whole unit was very basic and you could look right into the transistors since they have zero insulation. As far as I know it's not a sword unit but the basic resistor block unit which is supposedly cheaper but has three different manufacturers and I can't figure out which one.

I guess I'll just hang on for a month and a half until I drop the car off at my indy for some other repairs to get that valve fixed if it doensn't come off it with the hammertaps. Now let's see that amounts to: valve cover gasket, sump gasket, oil drain plug to be re-drilled, cooling system flush. Thank God this guy only charges 20 euro's per hour.

[genphreak]

What is PCB?
I'm thinking that next time I take it out I will test resistance on all terminals and solder if needed. The whole unit was very basic and you could look right into the transistors since they have zero insulation. As far as I know it's not a sword unit but the basic resistor block unit which is supposedly cheaper but has three different manufacturers and I can't figure out which one.

I guess I'll just hang on for a month and a half until I drop the car off at my indy for some other repairs to get that valve fixed if it doensn't come off it with the hammertaps. Now let's see that amounts to: valve cover gasket, sump gasket, oil drain plug to be re-drilled, cooling system flush. Thank God this guy only charges 20 euro's per hour.

Sorry, PCB; Printed Circuit Board. I'd just resolder every link and then test it. Sometimes one can find hairline cracks in the tracks on the board (from the expansion/contraction) or even the board itself (especailly around the transistors where it gets hotter). I'd do it myself as it can be done at home easily and good mechanics aren't (usually) brilliant with electronics as well. Nick

[Morgenster]

Sorry, PCB; Printed Circuit Board. I'd just resolder every link and then test it. Sometimes one can find hairline cracks in the tracks on the board (from the expansion/contraction) or even the board itself (especailly around the transistors where it gets hotter). I'd do it myself as it can be done at home easily and good mechanics aren't (usually) brilliant with electronics as well. Nick

Hah! No PCB then. This unit just has One plastic piece with the connector at one end and resistors at the other. They're very big resistors by the way. Just three open springlike wound wires (about an inch long) naked over a series of connections in the plastic piece. No cracks visible yet some blackening near some edges. Even after cleaning all that up nothing changed. It looks like something that should be fixed easily if broken. Maybe I should've taken a picture while I was at it. It doesn't resemble a SWORD and kind of resembles the resistor pack mentioned in www.bmwe34.net's write-up, yet it is not blue.
Maybe it's a eurospec thing, or at worst, a wrong replacement part that never functioned properly.

[genphreak]

Hah! No PCB then. This unit just has One plastic piece with the connector at one end and resistors at the other. They're very big resistors by the way. Just three open springlike wound wires (about an inch long) naked over a series of connections in the plastic piece. No cracks visible yet some blackening near some edges. Even after cleaning all that up nothing changed. It looks like something that should be fixed easily if broken. Maybe I should've taken a picture while I was at it. It doesn't resemble a SWORD and kind of resembles the resistor pack mentioned in www.bmwe34.net's write-up, yet it is not blue.
Maybe it's a eurospec thing, or at worst, a wrong replacement part that never functioned properly.

520i stuff is rare around here. Why that'd be different I have no idea. Maybe different heater controls. Anyway, buy new components if you can, solder em on and away you go. Often requires an elecontric shop if its a bit weird. If that sounds hard just get a replacement part- perhaps check on the online ETK to see which one it is first