rob83ke70 Posted December 24, 2009 Report Posted December 24, 2009 hey, just wondering if anybody can get a hold of a wiring diagram for the ac system on my 1990 toyota dyna yh81r, I've got something not hooked up or missing around the distributor/ac control area and my ac won't turn on..... its been pulled apart for ages, and I've just resurrected it (components/leaks/gas/etc) but I can't turn it on!!!! it was a kettering ignition system and its been converted to electronic, and I'm thinking an RPM signal is missing, but not quite sure :thumbsup: Robert. Quote
Bamboo Posted December 24, 2009 Report Posted December 24, 2009 R, funnily enough I don't have the diagram. Question: Pressure? If the gas isn't at the right pressure the pump won't cut in. If it is the only other electrical component is the clutch in the pump. You can hotwire this too see if it cuts in and out. hope it helps Quote
rob83ke70 Posted December 25, 2009 Author Report Posted December 25, 2009 got it sorted with a bit of playing around, I now have fully working air conditioning :thumbsup: Rather than an "idle up" solenoid on the carburettor, I have a control unit for the air conditioning (think pcb with capacitors and transistors attached rather than computer) located under the glove box. This has an adjustment for at what rpm the air conditioning cuts in, leading you to believe that it needs an rpm signal. The ONLY place to get this signal is from the negative side of the ignition coil (tachometer signal). After looking at a hilux/4runner wiring diagram, I have noticed there is a wire going from this control unit to the ignition coil, a black wire.... I have used a multimeter to find which black wire (there are a few wires not plugged in to anything near where the coil used to live) connects to the control unit. The vehicle has been retrofitted with an electronic ignition, with the coil inside the distributor, so the wiring is somewhat different, and the a/c has not been working for years. I connected this wire to the negative side of the coil, and lo and behold the condensor fan cuts in and out when the switch is turned on/off for the a/c. After some more playing around, I discovered there is another wire that needed to be plugged in located in the same area of the car, and after this was done, the a/c compressor cuts in and out as it should. I have hooked the high/low pressure switch up (retrofitted on the new receiver dryer) and it is all working as it should... meh.... auto electricians..... they make their money off lazy people lol! I'm happy to spend heaps of time on this, its much better for me than throwing money at it!!! Now I have a ton of stuff to do on it, but its all fairly little stuff, neatening things up and cleaning stuff, and little repairs, which should keep me occupied for a while. The main thing is, the engine goes and the air conditioning works..... I might add that is raining and quite cool outside today as well! Merry Christmas to everyone!! Robert. Quote
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