Mazda Repair: 1981 RX-7 Electrical, happenned, hot night

Question
After a 35 mile highway run on a hot night and stopping for a red light, the idiot lights went on and I heard a clicking sound.  It still ran OK, if a little lumpy at idle.  I found the noise was from the Choke and Check Relay.  On a short test ride later, I noticed that the voltmeter was on 11 volts when this happenned.  I shut it down, started it in 1/2 hour and it ran w/o idiot lights on and with volts at the usual 13-14.  The alternator tested OK at Autozone.  I charged the battery which had read 12.5 volts beforehand.  Is the relay the culprit or could it be something else?  $76 at the dealer for a new one.  P.S Car has been pampered its 138k miles since new.

Answer
That is an electronically controlled carburetor, a vain attempt at fuel economy and emissions from the 80's.  Try unplugging the choke coil at the carburetor and see if it re-occurs.  Also check your motor to body grounds and grounds at the battery.  Be sure you have good clean contacts to the alternator.  Voltage hunting for a good ground can cause similar issues.