i installed a tachometer in my 87 pickup . i t works but i cant find a good place to splice into a wire that controls the lighting for the tach, so when i turn on my running lights it turns on. any help would be greatly appriciated.

 

For a non-dimming backlight, you can just use any non-switched power wire, you could even use the power feed for the tach. Usually no issue with the backlight on during the day. For a light switched signal, you could tap into one of the lights running to the parking lights up front. Easy to find and then run that wire back to the cab.

If you want a dimming backlight, a little tougher, since the Toyota dimming lights use a floating ground with the dimmer in the ground connection. Most aftermarket backlights are tired to the case ground, so if you hook up to a dimming light, the tach backlight will work opposite to the rest of the lights; bright when they dim and dim when they brighten.

 

thanks