Suddenly lost spark, on two cars!

[dodj]

#18 isn't ground. It is the 12vdc supply from the alternator to power up the car and charge the battery when running. Unless I misunderstood you?

[72rtchallenger]

#18 isn't ground. It is the 12vdc supply from the alternator to power up the car and charge the battery when running. Unless I misunderstood you?

yes i think your right as i see it does run to the alt.

[CHL2T]

My Bad, yes, it is the black wire that runs from the BH block to the alternator. #16 red into ammeter, black out of ammeter, spliced into red, back to the BH and on to the Alternator
 

[CHL2T]

This, I believe, will be the final installment of the saga known as "suddenly lost spark" after spending a final 15 minutes dinking with #19 I have traced the problem to the ammeter connection. While having the tester hooked to the bulkhead end of 18 (terminal fried, replaced with spare) and ground, I pushed/ pulled and sure enough, power, no power, power, no power.

So, I will yank the dash, repair said ammeter connection, yank ammeter, test it, put it back together and.........

[Strawdawg]

The ammeter is a frequent source of problems and may cause a fire.  I bought one that had fried a number of wires and melted others together.  I am still soldering and repairing.  Add the problems caused in the bulkhead connector by the excessive current draw on the too small contacts, and, it is easy to see why there are so many suggestions out there to bypass the bulkhead connector and ammeter to eliminate the problem. 

[CHL2T]

I was thinking about just eliminating the ammeter, and I may just do that. I do have a spare that I will check first however, and make a determination from there.

[dodj]

I was thinking about just eliminating the ammeter, and I may just do that.

http://www.madelectrical.com/electricaltech/amp-gauges.shtml
One guys method of bypassing the alt. I modified it a bit on my car. Along with Hlight relays and disconnecting ammeter, didn't drill out the bulkhead, ran wire direct from alt to battery, used #16 and #18 as parallel feeds to the dash. I figured the two #12 wires along with the substantially reduced current demand (relays) will negate the need to drill it out.

[CHL2T]

Ammeter was absolutely toast, black side post, rusted and crusted. Don't have a spare ammeter, so I just connected them together. Fired it up and it now runs, although the lifters are now making a heck of a racket, need to get to the bottom of that, mayhap it's from all the cranking? Floats stuck? Who knows, it's running and thats all that really matters at this point

This thread is officially played out