1979 2000 - Electrical Stuff

[PDSnare]

Hello All!

I have been the happy owner of a 1979 Fiat 124 Spider 2000 with 63K miles--until recently...

Several weeks ago my battery exploded right after I started the ignition. Apparently, the voltage regulator on the original Magneti Marelli wasn’t regulating—allowing the voltage to hit over 16 volts. With my new multimeter, I was able to confirm. After replacing the voltage regulator with a new Mageti Marelli the Spider would no longer start. Facts to note:

*** In the last few months, I have also replaced the ignition coil.
*** Upon replacement of the battery, Spider fired right up, but again the OLD voltage regulator was allowing too much voltage
*** Tested the voltage at idle and at 2000+ rpms and multimeter showed the nearly 17 volts
*** Replaced voltage regulator, putting it on the original alternator
*** Didn’t start with new voltage regulator... confirmed alternator getting sufficient voltage.
*** Ignition switch: New Sipea OEM replaces old one BUT STILL no instrument lights / gas guage or interior light
*** The engine turns over but confirmed via one of the plugs that there's NO spark
*** New used ignition coil is not getting power, but checks out on OHMs
*** All fuses checked out OK
*** Checked the the ignition pick-up and it checked OK with three consistent OHM readings

Again, this entire process began with a blown battery as a result of a faulty voltage regulator.

*** Replaced battery and was able to confirm that voltage regulator was faulty and importantly, I was able to start the Spider again--everything appeared to be working
*** With new battery checked with a very brief start that the voltage regulator was faulty... replaced it with Magneti Marelli... THIS IS WHEN THINGS WENT SIDEWAYS:
*** With new voltage regulator affixed to the existing alternator it wouldn't start. BUT do have power to alternator
*** Still no instrument lights, horn, interior light, clock, BUT I do have power to headlights/hi-beam, blinkers, wipers

Alas, appreciate any input.

Thanks all for any wisdom, insight and hypotheses.

Phil

(northern VA – near DC)