Sunday, September 18, 2011

Energizing the 12V circuits

After the ignition switch was wired in, there was nothing stopping me from hooking up the battery and turning the key.  This should help me test the 12V circuits.

I had my son standing next to the battery with a fire extinguisher as I turned the key.  BEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEP!  I nearly jumped out of my pants.  I had tucked the horn wire into a space in the steering column, completing the circuit.  As soon as I turned the key, the horns went off at full volume.  I switched off the key and pulled the horn wire out.  I turned the key again and heard a click in the relay box.  I followed the diagnostic tests in the EA manual and immediately found a problem.  The green oil pressure indicator light is supposed to light up when the key is turned, indicating that the 12V circuit is on.  But the light didn't go on.  After tracing the wiring and checking with a meter, I found that the light bulb was bad!  I bought a box of replacement lights for the instruments, but that particular one still had its old bulb.  Lesson learned...  The rest of the EA tests with the batter and DC/DC converter were successful.

Next I tried pushing the electron pedal and heard the contactor engage with a loud clunk.  Success!

I don't have any of the original 12V devices in place like lights, blinkers, etc. so there was nothing else to test.  As I rebuild those parts of the car, I'll test them.