tach wiring for a 1979 440 whip

[chris12559]

Hey fellows,
Great boards lots of knowledge here! I wonder if you guys could help me with a issue that i just cannot figure out.....my tach has 4 wires coming off it a yellow and brown which are for the back lighting of the guages and a tan and an orangey/pink the orangey pink goes to green down into the main plug and the tan goes to brown.....the tach will move a little but even at full throttle it onky goes upto maybe 1000rpm... anyone help?

[oldscorpman]

i went and looked at my 79 whip tach wiring and on my tach there is a orange wire that goes to a union with yellow/red wire that goes to the voltage regulator.these 2 wire connect to a yellow/green wire that goes to one end of the lighting coil. the other wire on my tach is orange/black and that goes to a yellow wire coming off the other side of the lighting coil.the brown and the yellow wires on mine are for the back lighting. since the tach reads the lighting coil pulses for rpm i would test the output of the lighting coil or if you can test the tach on another sled.

rick

[chris12559]

Ok so ill i need to find is the lighting coil wire? Brown is ground right.....so which colour coming out of the engine is from the lighting coil? Do i take it right off the engine or after the regulator.....mine seems to have alot of wires different than yours....i dunno why maybe because it was an electric start? The tach i did see work before i bought it is a nos item anyways but we did test......