Why does my speedometer and tach not light up with headlights on?
1st photo shows dash with headlights on. And everything lit up but the speedometer and tach.
2nd photo shows dash with headlights off, speedometer and tach lit up.
A wiring problem.
Sounds like an accidental burglar alarm circuit.
Follow the Speedo/tach lamp feeds. They should be on the same cut as the rest of the instrument lamps.
Tim
Since the tach and speedo lights work with ignition on (full bright), and with the running lights on (dim-able), there should be a relay involved. The bulbs would feed from the relay common, ignition would feed normally closed, and the instrument light dimmer would feed normally open. maybe a bad relay or open connection on the N.O. side.
Ours should be the same. I'll look at my dash schematic tomorrow and confirm/refute this assumption.
Greg
Thanks for the input!
Tommy,
I totally forgot to look at my drawings. Fortunately, the grain O wheat lamp between my ears was dimly lit this PM and I remembered.
Attached drawing confirms there is a relay involved. It appears N.O. and N.C. are reversed from what I mentioned.
Greg