Makita How To

How did you measure the power at the switch Live to N ? that would rule out a break in the cable all that is left is Armature ,Stator coil and wiring to both.

the light is normally activates by the trigger, so either the switch has gone faulty or the wires running to bulb are contacting.
press the helpful button and check link below

Makita BTD142 Trigger Switch Replacement

Owners Manual contain the wiring diagram.
Makita Owners Manual

I KNOW IT !!! MAKITA the first gear is damaged the notches in the gearbox (planet-transmission)are grinded away about 2 or 3 mm are left and the gear shaft will not fit in the notches anymore , MAKITA the BDF 4** and many more models have all the same gear box problem, (NOT EVERY MODEL of MAKITA but much models ) LXT 18V and ??? because of the planet transmission GEAR BOX they are oft very vulnerable to switch over from one to 2 or from 2 to gear 1 the gearbox should anyway be replaced , and switch the topswitch on top of the machine without use the power switch at the same time its must standstill allways when shifting 1 to 2 or vice versa, inside the top switch there are special 2 springs build in inside to switch without turning because its have nothing to do with a synchronic gear box of a car , or choice to prevalence of repetition if you will not have again this trouble again buy Panasonic or Festool powertools this if you have people who are working with your tools you should never have problems with gearboxes anymore because of that notorious MAKITA problem by much models of Makita BDF4** and may be more models is also proven that have i so much this problem seen and repaired . but the gearbox itself from MAKITA is also not so expensive in compare to other powertools. but other tools moastly are selling individual parts like gearshafts and have metal notches instead of cheap plastic and not separate to buy, Makita delivered only 1 complete gearbox because its cheaper to get and all of the parts are new . marketing technical choice of MAKITA.

You can buy a can of electrical cleaner spray and try that. Otherwise the switch will need to be replaced.

This capacitor is only used for RF suppression... really IF it is shorted, then simply remove it. It should work fine without. just be noisy around radios etc. But if you want to replace it Radio Shack, or Radio Spares, should have one.

If you have the switch and know what tool you bought it for go to MAKITA.com and under Authorized and Factory Service centers in the tool bar, click on it and the page will open to allow you to view or download a schematic for this product. Hope this helps. Dave