I just purchased a Smith’s electronic speedometer with a gps sending unit from Nisonger. It came with instructions on how to wire it up; however, the instructions were lacking how to wire the turn indicator lamp. There is no room on the back of the speedo to insert the existing turn indicator bulb. I called Nisonger and they did not know how to do this, and were going to have to contact the manufacturer.
I thought that if anyone on the forum has done this before, I could get some help before I had to wait for them to get back to me.
If there is a tell tale lamp on the front then perhaps it is built into the unit, i.e. it doesn’t need a separate bulb in a bulb holder. If so, is there a spare wire or terminal on the back which would presumably connect to the existing feed to your bulb holder?
I just got this response from Peter Bayer at Nisonger:
Detailed below are the Instructions that I received from Smiths Technical Director this morning:
Lotus Speedometer only the single indicator light warning light has two inputs, Green/Red for LHS & Green/White for RHS, both are positive driven from the wires to the original warning light bulb. On negative earth vehicles the common Ground connector is internal to the gauge but for positive earth there is an extra external Black wire exiting the gauge.
Hope that this info answers any questions that you may have.