HEI voltage question.....
Thread Starter
Drifting
Joined: May 2005
Posts: 1,909
Likes: 6
From: Lake Arrowhead - Georgia > 72 Base Coupe & 74 BB Roadster
HEI voltage question.....
On my 70 GMC 1500.....with an aftermarket GM style HEI. I am hooked up to a full (non resistor) 12V ignition supply at the fuse block. I am showing 11.67 volts going into the distributor when the key is turned to the right (ignition).....when I engage the starter, the voltage drops to around 7 volts. It will not fire ... it won't even fire the timing light. Is this voltage drop normal or could it be "the problem".
I've swapped out a "known good" distributor to no avail. Both distributors fire right up in my 74 Vette.....NEITHER will fire in the GMC.
I am thinking MAYBE the ignition switch ? Actually I give up!
Suggestions? Spare brain cells?
I've swapped out a "known good" distributor to no avail. Both distributors fire right up in my 74 Vette.....NEITHER will fire in the GMC.
I am thinking MAYBE the ignition switch ? Actually I give up!
Suggestions? Spare brain cells?
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
When cranking, battery should never read lower than 10.5 volts at the terminals, if so the bat is weak or bad....
at the dissy + term it should never read lower than 10 volts....if so, and the battery is decent voltage you have a bad connection somewhere, some HOW....ignition switch, bulkhead connector, so to take a direct high capacity jumper wire from the dizzy + term to the bat directly and see if it fires....
at the dissy + term it should never read lower than 10 volts....if so, and the battery is decent voltage you have a bad connection somewhere, some HOW....ignition switch, bulkhead connector, so to take a direct high capacity jumper wire from the dizzy + term to the bat directly and see if it fires....
