Thread: 90 RRC Heater Blower Resistor

Sharing this work, there were some other old posts on this subject, and on other LR sites, but with some slightly different info relating to wire colours and part numbers.

Firstly - a few weeks ago the heater blower only worked in the I position - AC fans kicked it at the III position, but that's all.
Then on the weekend the car started developed a misfire - but after a few runs realised it was only when the fan was on - must have been shorting and sending some bad signals to the ECU or something.
So after some fiddling, checking the switch which was OK, found a few posts on other sites relating to the Blower Fan Resistor, which in the 90 models and over are pretty much out in the open air - to keep them cool they said. After a look at mine (passenger side behind the left plastic vent grille behind the bonnet) it was totally shot, rusty with wires sticking out. Note, carefully pry the plastic grilles out from the bottom, remove the push-in end and centre caps first as they also do some holding in.

Found a very nice looking replacement at various places overseas for around $70 US plus postage, but Atlantic British also has some nice photos. I've got more time than money at the moment so decided to make one the same. Went to RS Components web site and bought the correct heat sink resistors (part numbers listed below. Jaycar don't stock them, but RS ships overnight for free). The pre made resistor sets from OS you buy come with a plug, but with the caveat that if you don't want to take the dash apart to get at the plug, it should be spliced in externally. Their instructions listed a bunch of wire colours that mine does not have, but its easy enough to work out. Its only 5 wires, the 2 ohm resistor has its own pair, the 1.5 and 0.5 ohm share input power. I used 15amp wire, and attached the resistors to a piece of 80mm U channel and used the original mount holes from the old resistor to attach. If you are splicing, don't take out the grommet, its tough to get back in and you can just see the plug which is tied in place as a tease as it doesn't come out.

While I was in the binnacle space I sprayed some rust convertor on the brown patches, replaced the rotten earth wire to the wipers (which also work better now), and got some new foam to replace the bits of crumbling black dust which was all that was left of the old filters (20mm open cell foam from Clark, for $20 I got enough for 2 lots). The metal foam filter holder had to be drilled out to access the resistor, but only 2 pop rivets.

It was fiddly work, especially soldering the new unit to the old wires while hanging over the engine bay. The blower now works nicely, and no engine missing. Just in time for some fresh air for summer.

Part numbers: RS Components - there are some options, but I went for the ones available for overnight shipping. Cost me $20 for all 3.
They are all 50W Aluminium Housing Wire Wound Resistors. These Arcol ones are made in the UK.
2ohm - Arcol HS50 2R 252-2811
1.5ohm - Arcol HS50 1R5 160-900
0.5ohm - Arcol HS50 R5 158-452

Photos attached are the finished unit, in place, and one of the old resistor

IMG_3127.jpgIMG_3129.jpgIMG_3130.jpg

I used black shade mesh folded over itself a few times behind the plastic vents many moons ago.

It's still there, like new.

DL