29 replies to this topic

[RichH]

Is this unique to the VX220 or is it the same as other Vauxhall models? I've been trying for ages to get hold of a new resistor pack for mine but the only people that I've found with one only want to sell the entire heater unit, which I don't need. If I can pick one up from a local scrappy from an Astra or something it would be ideal. Cheers, Rich

[rabidh]

As a fix, you could buy a decent high power resistor and put it in across the one thats blown. The failure of position 1 seems pretty common, so I wouldn't be surprised if one from a scrappy would fail after a few months too.

[RichH]

As a fix, you could buy a decent high power resistor and put it in across the one thats blown. The failure of position 1 seems pretty common, so I wouldn't be surprised if one from a scrappy would fail after a few months too.

I thought of doing that, but the resistors are not typical electronic ones, plus I have no idea what resistance I'd need to fix in place. It's for the slowest fan speed (if that's what you mean by position 1).

[rabidh]

You can definitely get meatier resistors from Farnell/RS, but you should be able to find them elsewhere...

Maplin do 10W ones for 25p - you might need to buy a few and put them in parallel to get the resistance down/power dissipation up. I guess you'd just have to guess the resistance based on what the others resistors in the block turn out to be.

Maplin resistors

I haven't looked at the speed controller block but you could maybe make your own resistor just by winding some copper wire around something that isn't going to melt.

[rabidh]

Right. Didn't have much to do today so I decided to fix mine. The resitor pack is in the top of the heater, held on by 2 rusty screws. I didn't manage to get the last one out so I just had to pull (hence the white lug on one of the mounting holes).

To be honest calling it a 'pack' seems to be a bit optimistic. behold - two bits of coiled wire!!



And the one covered in cement type stuff appears to be broken. The other one is about 1 Ohm, so it looks like the maplin resistors are out of the question. I'll have a go at rolling my own and see how it goes!

[rabidh]

Ok. Very, very quick howto:

1. Pull off the aluminium heater ducting
2. There are a few wires wrapped in a black ribbed pipe that go down towards the heater (where the ally pipe came off at the bottom). They should split halfway down, with one branch going off deeper into the car and one plugging into the heater right under the brake servo in a really inconvienient place. Undo the 2 self-tapper screws on either side and pull the unit that the wires plug into carefully out (its the thing pictured above - bending the wire coil wouldn't be good...).



3. Check with a meter which coil is broken, and unsolder it.
4. Get about 2 foot of that twist tie stuff (used for tieing stuff up in the garden, or tieing bags up in the kitchen) and strip off the plastic surround. Check the resistance of the length of wire - Around 2 ohms is the right resistance assuming that the lowest fan position has died.
5. Wrap it tightly around something about a quarter of an inch diameter so you have something like the coil thats on the resistor pack already. It'll be way longer, but i found if i used something of a bigger diameter then the coil got really messy.
6. Solder the coil on (the tie wrap stuff is a bit crap so it needs tinning first really) and bent it so none of the coils are touching and it doesn't get in the way of the other coil - it turns out the coil can stick up quite a way without fouling anything.



7. And stick it all back together... I vasolined all the contacts and where the screws go back in, and used some screws that had something resembling a head on them still.

To be honest it would be much better to buy some decent resistors, or even to find a resistor pack off something else, not even bother getting the old resistor pack out, and mount the new one somewhere else. After all, you could just use spade connections to connect to the resistor pack connector.

I remember that the sierra heater fan had a little box on the top with resistors in that might do quite well. There's a pic of the original heater fan In a kit car. There are only 3 wires so wiring it up would be easy.

Edited by rabidh, 28 August 2006 - 03:41 PM.

[rabidh]

Not sure about commercial use infringements but:

I've just looked around and I reckon I can make a batch of new resistor packs - with proper aluminium cased resistors bolted onto a patch of aluminium sheet, and then 3 fly leads to connect to the original connector - and it could just be bolted/cable-tied to the chassis.

using something like these guys:


It'd probably work out at around £20 each if anyone's interested. I'd really want at least 10 people before I started though...

[RichH]

That's beyond the call of duty mate. Thank you very much I'm must say that I also managed to get the front screw out when I've taken a look this afternoon and failed with the rear one (I guess the one that you pulled out?). From your pics that really look like the most archaic piece of electronics I have ever seen in any consumer item. Especially in a £20k+ high performance sports car. I mean, how much did they really save by using those parts instead of proper durable resistors? Now I just need to find an ohmeter that I can borrow cheers mate, I owe you a pint. Rich ps. I've just seen your other post. If you ever do make up some of those resistor pack I'd definitely buy one

Edited by RichH, 28 August 2006 - 04:50 PM.

[pugwhizz]

pardon my ignorance but why is there only 2 coils when there are 3 fan speeds? do they use 1, then the other, then both or sommat?

[rabidh]

I'm must say that I also managed to get the front screw out when I've taken a look this afternoon and failed with the rear one (I guess the one that you pulled out?).

Yep. The head was just too rusted - and its awkward anyway. I was going to drill it out, but i couldn't even get a drill in! The lug is like the standard trim fixing things really - it sortof expands out and jams in - it seems pulling/twisting mine didn't really damage anything.

the most archaic piece of electronics I have ever seen in any consumer item

its not great Even on the 20 year old sierra they'd used substantially thicker wire and wrapped it around little ceramic cylinders.

pardon my ignorance but why is there only 2 coils when there are 3 fan speeds?
do they use 1, then the other, then both or sommat?

1, then the other, then no resistor at all And the 3 wires are basically just 12v in, then power out via 1 resistor or power out via the other. God knows why they used a plug with 4 spades (2 of them are shorted together).

edit: I really don't think the tie wrap wire is the best thing to use (but its the closest I had) - I tried some heavy duty mains wire, but even 1 foot of the earth line was 0.2 Ohms! Probably some single core copper wire from Maplin would be a better bet.

Edited by rabidh, 28 August 2006 - 06:05 PM.

[Flecski]

God knows why they used a plug with 4 spades (2 of them are shorted together).

edit: I really don't think the tie wrap wire is the best thing to use (but its the closest I had) - I tried some heavy duty mains wire, but even 1 foot of the earth line was 0.2 Ohms! Probably some single core copper wire from Maplin would be a better bet.

They probably use the same plug in other cars which have four fan speeds.

Maplin sell resistance wire:
Maplin Resistance Wire

At 4.2 ohm/m - if you need one 1ohm & one 2 ohm piece then thats less than a metre per unit. The pain would be in the winding.
I can't guarantee what current they can take, although it does mention it can be used for heating elements which would indicate a reasonable value.

Good luck

Flec

[walshy123]

ok guys speed 1 and speed 2 are now gone. just to clarify, speed one is 2ohm and speed 2 is one ohm?

[walshy123]

ok guys speed 1 and speed 2 are now gone.

just to clarify, speed one is 2ohm and speed 2 is one ohm?

guys im just bringing this up again as i want to get this sorted.

im looking at resistors. anyone any idea what wattage i need?

[SteveA]

Resistors will be far to powerful you need resistance wire, zirconium is the way to go. 2ohms for speed 1 and half that for speed two (i would imagine) edit - FYI resistance is measured in ohms not watts.

Edited by SteveA, 25 December 2008 - 11:30 PM.

[davep24]

looking at TIS, fuse 3 is the one for the fan blower and thats 20A, so i would say a resistor rated at 300W should be ok

[walshy123]

Resistors will be far to powerful you need resistance wire, zirconium is the way to go. 2ohms for speed 1 and half that for speed two (i would imagine)

edit - FYI resistance is measured in ohms not watts.

thanks mate, im aware that resistance is measure in ohms, power rating is measure in watts. resistors have two main parameters - resistance and power rating. it was already stated that the resistance required is 1ohm and 2ohm, so i was asking what power rating i needed

why do you think a resistor would be too powerful? why would a 1ohm 300w resistor not suffice?

[walshy123]

looking at TIS, fuse 3 is the one for the fan blower and thats 20A, so i would say a resistor rated at 300W should be ok

thanks dave

Edited by walshy123, 17 January 2009 - 04:07 PM.

[slindborg]

Resistors will be far to powerful you need resistance wire, zirconium is the way to go. 2ohms for speed 1 and half that for speed two (i would imagine)

edit - FYI resistance is measured in ohms not watts.

thanks mate, im aware that resistance is measure in ohms, power rating is measure in watts. resistors have two main parameters - resistance and power rating. it was already stated that the resistance required is 1ohm and 2ohm, so i was asking what power rating i needed

why do you think a resistor would be too powerful? why would a 1ohm 300w resistor not suffice?

I'm going to use some 300-500W ceramic (or better yet Transistor packaged ones) resistors when I revamp the heater setup.
Good enough for an MGF, good enough for a plastic skip!

As you say 20*12 = 240Watts.... on full tilt, so with the resistors limiting the voltage (lets pretend the motor has a 1Ohm resistance too) by half and to 1/3rd you should be fine

[Anarchy]

Position one and two has gone on mine am I right in thinking position three will just keep working because there is no resistor or could that be about to go? What happens if you get the resistance wrong, different speed, will blow straight away again?

[walshy123]

Position one and two has gone on mine am I right in thinking position three will just keep working because there is no resistor or could that be about to go?


What happens if you get the resistance wrong, different speed, will blow straight away again?

yes speed three should work forever. (im in the same boat as you, its all or nothing)
wrong resistance = different speed or no speed at all