My aircon blower wont work. It sometimes comes on unexpectedly when switched on but 99% of the time..nothing.

I take help from online websites that have this service like helping in repair some like reliable-store have instant help.. others are a bit slow which I don't prefer... rest is up to u.. U can also get free manuals

CHECK FOR VACUMN OR SWITCH

When you say heat only works sometimes are you talking the blower fan only running once in a while if it is the fan your talking about it sounds like a loose connection either on the switch or possibly on the blower mother itself

Heater blower? Well it's either the switch or the blower motor. Probably the motor if you use heat or AC often, and it's happening intermittently. Test the motor with an outside power source (like another car battery), I bet it acts screwy. It may just be dirty, depending on where you drive, or some small animals could have made a home in there. Hopefully nothing has come undone in your dash, that's a mess.

Go pick up a $20 Chilton or Haynes manual for your truck, that will help greatly, it's worth the cash.

Good luck!

First check battery to motor ground, battery to body ground and motor to body ground strap for corrosion under bolts. Bad ground can cause all sorts of electrical problems. If these are ok, the most likely culprit is the blower motor itself or the switch.

Sounds like the switch,I have had the same happen. Won't work on 1or2 but 3-4 worked fine. The next day 1-2 worked....? With out a meter to check it will be guess work.

Try replacing the blower motor resistor. That controls the speed of the blower motor.

First possible solution: On many Hondas the AC button will only light when you slide the blower fan on. (The right slider knob on a 92 Prelude)

The second solution: When you notice your AC button NOT lighting, pay attention to see if your vent selector buttons actually switch your air direction from floor to face to defrost, etc. Also, take not to see if they fail to light also. If the other buttons don't light, you may have to pull out and disassemble your climate control cluster to actually "re-solder" the terminals on the GREEN PLUG receptacle back on to the circuit board. It's a difficult task to get out and in but if you're very careful, nothing gets broke. I have done this repair recently to a Prelude and it worked. There is not enough reinforcement on the board for this plug and it wiggles enough to cause a cold solder (broken connection).

I had the exact same problem, I changed the "ignition switch" because the contacts inside were burned, this is why you see all those troubles coming in and out at different moments. It costed me 150$ to do it myself, buy the switch on an online reseller, must cheaper than the dealer! Now everything is back to normal on my Grand Prix GT 99 exept that my headlights don't light up automatically when starting the car... I have to check my fuse/relay and switch to make sure everything is ok on that side.

Good luck.

sounds like an "open circut to me. check for loose connections at the blower motor, blower motor resistor, and blower motor switch, you may have to tap each one several times to produce the railroad effect