Viltage

rglaab

Member
Working on my 30 Pickup. Batt voltage at 6 but voltage at distributor is 3.5. New battery and cant get fire. Help
 
I assume that is with the points open???. If not, open the points then trace the voltage from the battery to the points. Start at the terminals on the junction box on the firewall. Unscrew the wire into the distributor, if you can, and check the voltage there. When you put it back in don't screw it in so much that it shorts out. If you still get low voltage with the points open then try a new condensor and check the lower plate and the wire that leads to the upper plate in the distributor.

You should be getting zero voltage with the points closed. If not then the points are dirty and need to be dressed. I use a folded up piece of 400 grit wet and dry sand paper with the points closed and then clean the points afterwards with a clean piece of printer paper. There could be other problems too.
 
Yep, just as nkaminar said.

6v at open point arm
0v at closed point arm
I'd also recommend checking the coil. Coil should be 1.5 ohm [ not 3.0 ohm]. Check ohm reading and input and output voltage. Should be battery voltage.
 
To add to the above, make sure you use a consistent ground, ie the same place each time, otherwise you muddy the waters with possible faulty ground paths.
 
I would say #2 nailed it.
I worked on an A with ignition problems and found the spring loaded end of the popout only had a couple stands of wire still connected.
 
Yep, just to continue on the fellas said about the primary lead. The insulation also can go bad right where it screws into the distributor, so wiggle it around when checking it.

Just as an aside. I prefer the aftermarket small diameter flexible primary lead. Its easier to put the key switch [ a good quality after market] before the coil and to remove the distributor.
 
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