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No Spark

Posted: Mon Oct 24, 2011 8:10 am
by lgt
I am trying to get the engine running in my 1955 m38a1, It has no spark
The #12 wire to the distributor has no power. I traced that to the #10 wire out of the Delco Remey regulator. I do have 24 volts out of the regulator going to the amps gauge #8 or #9 wire. Any thoughts or comments
welcome.
Thanks
Larry

Posted: Mon Oct 24, 2011 8:35 am
by wesk
Does wire 10 have 24 volts?

Posted: Mon Oct 24, 2011 10:29 am
by lgt
#10 does not have 24 volts. When you check it with a volt meter the needle moves showing some voltage but then goes down to zero

Posted: Mon Oct 24, 2011 11:00 am
by wesk
1-Ok power starts at the battery. Check both Pos & Neg cables corrosion free and tight.
2-Then to the starter terminal. Check for loose or corroded terminal at the starter.
3-Then wire #4 goes from the starter terminal to the regulator plug. Disconnect the plug and check pin A for 24 volts at the plug end (firewall harness plug). Make sure pins and sockets are not corroded.

Image
Note my schematic at the top is opposite sides to the photo.

4-Now connect an ohm meter or test lamp or continuity tester to pin C (wire #10 on the firewall harness plug and the other lead to the #12 wire connector at the harness side of the distributor plug. With the ignition switch off the meter should show an open or the test lamp will not lite. With the ignition switch on you should have continuity shown with no or very low resistance or the test lamp will lite. If this test failed and with the switch on there is still an open circuit check the connectors at the rear of the ignition switch.

5-If 4 worked as posted then re-connect the regulator to firewall harness plug. Connect your volt meter to the distributor's harness plug wire #12, Turn the ignition switch on and you should have 24 volts on the meter.

If all above checks ok except still no power at #12 wire then your issue is internal to the voltage regulator where power from wire #4 is not getting to Pins B & C.

The only way to inspect an electrical terminal connection for corrosion is to disconnect it so you can see the contacting surfaces!!!

This is where the GI electrical system test lead adapter kit earns it's keep!!

Posted: Mon Oct 24, 2011 11:07 am
by lgt
Thanks Wes, I will check it out And report later

Posted: Mon Oct 24, 2011 4:28 pm
by lgt
Thanks for the help Wes, failure on step 5 no power out of B&C

Posted: Mon Oct 24, 2011 6:27 pm
by wesk
Do you have a GI electrical lead test adapter set?