Okay, I've had my autometer tachometer (with an unreplaceable bulb) for over a year now and I really need help. I want to hook its light up directly to the dash lighting so it can be turned on and off with the rest of the lights. I've got it connected to a red/green wire above the radio so I can see it at night, but it turns on every time I turn the key to ACC or further. I spent two days in the sun-baked truck and Chilton guide looking. Can someone please help me?
to make it easy to find a source wire, id tap the pos from the tach light into the lead for the heater control light behind the dash. then just ground out the other wire somewhere. then it will come on with the dash lights, and dim with the rest of em. course the really easy way would be to get a SR5 cluster with a built in tach.
On my '86 motorhome, I tied into the wires going to the transmission light in the column. Easy to reach after removing the lower column cover. The trick for the dimming is that you have to tie into the ground wire too. The dimmer switch controls the ground resistance, not the live side of the light - which could still use the radio power tap.
By the way, there's no negative side to the light's wire, just the coil's wire(green), a power wire(red), an engine ground wire(black), and one light wire(white). When I have the time, I'll try sticking it in behind the AC/ Heater controls, but I've got to lubricate my window tracks first.
Its possible the tach uses an LED bulb, which if the case doesn't dim like a normal bulb, its either on or off, tapping into one of the dash light leads should still make it work only when the lights are on, just won't dim.
LED's will dim. I'm an electrinics junkie and I have them on my bike with a special fader turn signal relay. When I put the tach in my truck I connected it to one of hte wires off the dimmer switch on the dash panel under the steering column.
Which one? Did you connect it to a wire directly connected to the dimmer? What was the colors on the wire? I'm sorry that there are so many questions, it's just, other than installing a switch for it, I can't turn the light off without the truck being off.
it depends what voltage they are running at..If regulated at 12v as soon as it dips under they will turn off..if regulated at 9v you will get a little bit of dimming before they turn off..but
Thanks. I actually found a wire I could connect it to (left hand green @ clip heading toward AC lighting) and now it turns on and off with the lights, however, it will not dim, but that doesn't matter to me, they are always on full brightness.
