87 300TD ac blower REWIRE/redesign
 

ever since i've had the car the AC auto climate system has never worked as it should, which is fine, since all i needed for it to do was to switch on the compressor clutch and provide a single blower speed(in my case...the lowest setting), which it did.

anyway...just yesterday... the "porcupine" unit decided to quit... it was failing, coz during the few times that i tried to switch to full blower speed the unit quits after just a few minutes. anyway... it eventually died. pressing on the buttons the compressor engages, but no fan speed.

the blower motor is fine.

preliminary testing shows no voltage at the x64 plug, that's the plug that goes directly to the porcupine/motor. what could this mean? the push button unit still has illumination and does engage the compressor...

i temporarily installed a relay which is triggered by the compressor lead and supplied directly by the battery to power my blower motor...at full speed all the time. i'm able to live with this setup... as i can probably wire a resistor block to control fan speed with a rotary switch as my worst case scenario. (reverting back to stock by replacing the porcupine is NOT an option.)

the only other problem with this temporary setup, aside from just 1 fan speed, is that whenever i disengage the compressor, the fan dies with it...since the relay is energized by the compressor clutch lead.

Sooooooo... anybody have any suggestions where to wire the relay instead of the compressor clutch lead? i was supposed to wire it to the x64 plug, but right now there is no power there. I CAN try to investigate the lack of power at the x64... is there a relay/fuse along its path to the pushbutton control unit? diagrams show no such thing.

Ideally i'd like to use the 3 FAN buttons to control 3 relays which will pass thru a resistor block. ANybody know if i can isolate signals from these three buttons? thanks


hahaha... 500th post!!!

why not replace the porcupine? it's an '87 so maybe it lasted 23 years?

aside from being a tad expensive, IF there were 1 available here, i want a medium blower setting. :) all that automatic crap is just that...crap. :) the simpler the better.

i may just end up hacking the pushbutton unit, particularly the fan buttons