29 replies to this topic

[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?

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

any links to these?

[slindborg]

www.google.co.uk

[182ian]

Sounds like you have had good fun today! i have wondered recently why my no 1 fan speed is so quite. Probably not working then. haha. 2 and 3 are fine. We fit aircon sytems in the old cars at work. I wonder how the sizes of the units compare. hmmm

[rabidh]

My previous resistance wire bodge died, and I've now used 10W resistors from maplin. I used 1 ohm and 2 ohm, but decided to increase the power handling by using 2x2 Ohm in parallel, and 2x4 Ohm in parallel. I araldited them to an aluminium heatsink, as they did get quite hot after a while and I honestly think they wouldn't take it if they were on their own.

To be totally honest I think speed setting 1 (2 Ohm) is now a bit too slow, so I'd be tempted to go for 1.5 Ohm and 0.5 Ohm - or maybe 1 Ohm and 0.5 Ohm.

I used these because I was in a hurry and wanted to pick them up from a shop:
http://www.maplin.co...x?ModuleNo=2181

But really if I were you i'd just save myself some trouble and buy a 100W OR47 (speed 2) and 1R5 (speed 1) from here and don't put them in parallel:
http://www.rapidonli...resistors/65217
and then screw them to a sheet of aluminium through their mount holes. It'll cost you £7, look sexy, and it'll never, ever die.

[james141]

I dont see what the rush is to fix this, does anyone actually use the heater/blower on any setting other than full as even then it is like an asthmatic flea ?

[rabidh]

I dont see what the rush is to fix this, does anyone actually use the heater/blower on any setting other than full as even then it is like an asthmatic flea ?

I use it... Sometimes you've got to find that balance between feeling your legs and being able to hear yourself think

[james141]

I dont see what the rush is to fix this, does anyone actually use the heater/blower on any setting other than full as even then it is like an asthmatic flea ?

I use it... Sometimes you've got to find that balance between feeling your legs and being able to hear yourself think

Its not that loud on full especially compared to the roof off/radio/exhaust/k+N etc

[slindborg]

I dont see what the rush is to fix this, does anyone actually use the heater/blower on any setting other than full as even then it is like an asthmatic flea ?

TBH if its a mechanical part on the car I like to know it will work as "intended" even if its never used.... cosmetic stuff can FRO as far as im concerned lol.

[techieboy]

cosmetic stuff can FRO as far as im concerned lol.

Good to see you've mellowed with fatherhood. In the old days I'm sure you'd have never used an abbreviation.

[slindborg]

My previous resistance wire bodge died, and I've now used 10W resistors from maplin. I used 1 ohm and 2 ohm, but decided to increase the power handling by using 2x2 Ohm in parallel, and 2x4 Ohm in parallel. I araldited them to an aluminium heatsink, as they did get quite hot after a while and I honestly think they wouldn't take it if they were on their own.

To be totally honest I think speed setting 1 (2 Ohm) is now a bit too slow, so I'd be tempted to go for 1.5 Ohm and 0.5 Ohm - or maybe 1 Ohm and 0.5 Ohm.

I used these because I was in a hurry and wanted to pick them up from a shop:
http://www.maplin.co...x?ModuleNo=2181

But really if I were you i'd just save myself some trouble and buy a 100W OR47 (speed 2) and 1R5 (speed 1) from here and don't put them in parallel:
http://www.rapidonli...resistors/65217
and then screw them to a sheet of aluminium through their mount holes. It'll cost you £7, look sexy, and it'll never, ever die.

Actually, you shouldnt need to heatsink the 100W resistors as they are rated at 50W@25deg C with no heat sink.... should be more than enough, esp if you can mount them in the air flow pre heater rad.

cosmetic stuff can FRO as far as im concerned lol.

Good to see you've mellowed with fatherhood. In the old days I'm sure you'd have never used an abbreviation.

I know, its all good... I could even be nice to people now lol