No Power: New Battery and Ignition Coil

Hello all,

Background: New battery. I ran some power checks (with a light tester) to see where I was getting power. Power going to ignition coil seemed intermittent...it didn't have power one day and had power the next. I took off old ignition coil, tested resistance and had an open circuit betweet terminals. Bought a new coil and installed. Car did fire twice but never started. Ran some spark checks on plugs and ignition wire (center wire on distributer) and no sparks. Checked power to coil...nothing. Now when I put the key in the ignition and turn to run there is no power at all. No lights, radio, etc. Battery is fully charged still (put it on a charger). Ballast resister is good (had a new one I tested). I did attempt to crank it by jumping the switch/relay on the firewall using a screwdriver to bridge. It cranked, but no sparks.

Just from chatting with others, they have suggested checking the fuses. They all looked fine, but I'll check the ends to make sure they are still intact and don't spin. Could just be hard to see the break if it's come away from one of the fuse ends.

Possibly the voltage regulator? Wanted to get some opinions before starting tracing the wires from the battery onward.

Reply to
66Barracuda
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Reply to
NewMan
1966 Plymouth Barracuda...sorry for leaving that MAJOR part out ;O)
Reply to
66Barracuda

Well you could try jumping from battery to the + side of the coil and see if you get spark.. that would eliminate the distributor parts and the rest of the primary ignition wiring.

Reply to
me!

Well,

Last night I had a little time to do some checking. Car was still dead when I started (i.e. no power to anything). Started checking firewall connections. A lot (most) of the clips/connections are corroded. I'll get a new wiring set eventually. After pushing and pulling on various wires (I think the fusible link attachment point is the culprit), I checked power again and surprise, it was there. Power going to the coil. Checked for a spark coming from the coil ignition wire and nothing. Maybe I should change the plug wires while I'm at it. I don't think plug wires are the problem, as I tested the main ignition wire (connecting dist. to coil) by putting one end to the + side of battery and checking the other side with a light tester. 12v was at least going through the wire. I don't know how helpful or even if that tells me the wire is good, but it seemed to have continuity. Wiring to coil seems ok: one wire to( + ) side going to ballast resitor, two wires to ( - ) one going to dist. and one to tach (a small cylindrical piece behind the coil).

Reply to
66Barracuda

If you have 12V showing up at the *+* connector on the coil, that is a good sign. The points in the distributor is what switches the coil on and off to provide the pulsated DC that is needed to invert the voltage to provide spark. I would suggest checking the points and condensor in the distributor next. Check the points for pitting and wear, and set the gap. The lobes on the distributor shaft should be lightly lubricated for smooth operation. Usually, a new point set will include a capsule of this lubricant.

With my 1964 Plymouth 273, a good sized spark would jump from the coil tower with the wire disconnected, and the starter cranking the engine.

Is the distibutor still the 1966 one, or has it been swapped out and electronic ignition installed? Chrysler offered electronic ignition retrofit kits as early as the mid-1970's for earlier cars.

If you have electronic ignition, then the diagnostic procedure will differ.

-Kirk Matheson

Reply to
kmatheson

The firewall bulkhead connector is the source of many problems in the older Mopars.

When troubleshooting the ignition system you have to understand how the ignition switch works. When the key is turned to Run, one side of the ballast resistor is powered (usually with a blue wire) but when the switch is turned to Start the blue wire shuts off and the wire on the opposite side of the ballast (usually brown) is powered to bypass the resistor for a hotter spark when cranking. Just because there is power to the coil in the Run position doesn't mean there is power in Start; you need to check for voltage in both key positions. If there is no power in the Start position check the bulkhead connector first and then the switch.

You might also consider disconnecting the tach sender temporarily to make sure a fault in it isn't shorting out the whole ignition system.

Reply to
John Kunkel

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