Good Replacement Coil

Hi all. I have a 1973 CJ5 with a stock 304. It currently has no spark and I have troubleshot and found the following:

With key on and points open I have 12 volts to the positive side of the coil, but only 0.5 volts on the negative side. I removed the wire (to the distributor) from the negative side of the coil and still only 0.5 volts. Additionally, the plugs are showing some carbon fouling.

This has lead me to decide I need to replace the coil. My question is this - does anyone have recommendations on a good brand of coil? Not looking to swap to HEI or anything like that, I have no problem with the stock arrangement.

Thank you!

 

Accel , Delphi, or Mallory. ~ $ 25

 

I have no experience with any of those brands. Accel and Mallory are both performance brands. I thought that Delphi was split from GM at one point and is now an OEM and replacement parts company.

Standard (SMP products) has been around forever and makes their business selling aftermarket. They also supply house-branded products to the parts stores.

Standard UC12 or UC12X 1972 JEEP CJ5 5.0L 304cid V8 Ignition Coil | RockAuto

I'd be tempted to buy two of the WVEs and carry a spare. WVE is Wells Vehicle Electronics which I believ was Wells-Airtex for a while, and is another legacy name in the aftermarket business.

 

Thank you both for your help. It turns out a friend who owns a repair shop had an accel he didn't want that he just gave it to me. Its new in the box and the correct fit (number 8140). Since I cant beat the price I'll go with it. I think I will order a back up UC12X as well. Thank you again for your advice!

 

Generous friend!

The most likely time for electrical/electronic parts to fail is right away ("crib death.") If I bought a second coil as a backup, I'd use it for a while to "season" it and ensure it wasn't going to be bad out of the box. Then I'd pack it away and switch to the other coil.

( Just as an aside, electronic devices have very much the same longevity profile as people. The very young are the most vulnerable, then as childhood passes the subject heads into long, low-risk youth and middle-age. As old age arrives, the day-to-day likelihood of failure increases then plateaus at very old age. )

 

Thanks for all your help! I put the new coil in and got 12.3 volts on the positive side and 12.3 on the negative side with points open. Thought I had solved the problem. Turned it over once, no start. Turned key a second time and "click". Sounds like a solenoid, battery is new and sits on a maintainer (plus reads 12.7 volts). Now 0 volts to positive side of coil. The fun continues! If anyone has any ideas that will shorten my troubleshooting feel free to chime in. The wiring is original, so no telling what I might have disturbed to cause this.

 

Solenoid

 

Yeah - 12 volts in, but not out when attempting to start. Also, that distisinctive "click" that says relay no close. Question - does anyone know if that would also cause the "I" post (terminal) to go to zero volts as well?

 

Does the engine turn over when you turn the ignition switch to "start?"

The "I" post is connected to the big post that goes to the starter motor. It's supposed to give a full battery voltage to the coil when starting, bypassing the ballast resistor. I don't see how the "I" post could be zero when cranking and the starter motor spins the engine.

 

I'm sorry, I wasn't clear. Starter motor doesn't turn engine over. Just a single "click" (from the solenoid) when ignition is in start. I think you may have answered my question - no voltage out of solenoid to starter when ignition is in start also means no voltage to "I" terminal.

Only thing I can't figure right now is that I also get no voltage at positive coil terminal with ignition in run. I had 12.3 volts at positive coil terminal when I first put the new coil in, but it went to zero at the same time the solenoid stoped turning over the engine (and began making the tell tale "click" that says the relay isn't closing). In any event I'm pretty sure the solenoid needs to be swapped out- seems like its a problem, although there may be another as well.

 

What kinda meter are you using.?? If it is a digital you are getting fooled. You really need an analog meter. Sounds to me like the battery is FUBAR or a bad/loose connection

 

Pssh. If the engine won't crank, why are you messing with the ignition?

Bad battery most likely. You want current from the battery, not voltage. Voltage reading tells you almost nothing about the battery condition.

Take it out and bring it to your local auto parts store for testing. Clean the cables and posts till they are shiny.

 

Battery is brand new. I put it under on a load tester and it's ok. I'm messing with ignition because that was the original problem (no spark)- traced problem to coil, replaced and had 12 volts on positive coil terminal and 12 on negative terminal with points open, 0 volts with points closed. Thought I had the problem fixed, went to start it and it turned over (without starting) once. Tried to start again and solenoid clicked, starter does not turn over engine. Now - solenoid just clicks, battery checks out ok, 0 volts to coil on either positive or negative terminals.

 

Once again. Are you using a digital meter? Might try the old by pass the solenoid with a pair of pliers trick. And have you looked for a loose connection. Maybe swap the battery into another vehicle and see if it turns over..

 

Check the ground to the solenoid. I ran into an issue where the solenoid would only hit once and then nothing. Try to jump the solenoid as well try using a jumper cable from the battery to the starter side that should give you an idea too

 

My 77 cr5 had a prestolite ignition which was nothing but trouble. I converted to points. The proper coil should have 6 volts with key in run position and 12 volts in start position for positive. 12 volt start power comes from starter solenoid. 6 volt comes from key switch with a ballast resistor or resistance wire. Low coil voltage is normal to a certain spec because of winding resistance. . Check coil with ohm .Meter . I FORGET VALUES SOMEBODY PLEASE CLARIFY. CONDENSERS ARE note to be taken for granted. Very necessary . I used to carry spare coil ,points , and condenser and never needed them. I never did find any books that explained this in detail. I was fortunate to have a few experienced friends in their 70s who had a clue what was going on.