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PMag Leads are Loose

ChrisMcC

Member
My PMag leads (at the mag) are not confidence-inspiring. They slip on, but do not have the comforting "snap" fitting like at the plugs. On take-off roll today, one came loose, the engine began sputtering, and I aborted the takeoff.

Is there a way to more securely attach the leads to the mag?

Thank you!
 
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I agree, it’s a weak connector that is used on the Pmags. Do yourself a favor and tin the ends of the wires that slip into the connector. The screw clamps on the connector squishes the stranded wire, and tinning the end first prevents that and makes a more secure connection. You can really crank down tightly on those screws if you do it this way, without breaking any of the ends of the strands.
 
I think the OP is talking about the spark plugs leads on the coil tower. A bit of vasaline on the boot and a conscious effort to seat the boot as far as possible on the tower (rather than the terminal) will help. There are millions and millions of cars with this coil/wire connection and they don't fall off.

If not, and he's talking about the primary wiring connector, then crimping a brass tube/ferrule on the end of the wire gives the screw something to bite onto without creating the brittle segment of wire solder can cause.
 
If the wires easily slide on/off the coil, you've got wear in the system. Either the wire ends, the coil posts, or both. I don't exactly remember the tactile feel you should get (maybe two light clicks as a wire goes into place), but I noticed this issue on my the last condition inspection and replaced both the wires and coil to correct the situation.
 
+1 for checking with Emag

Last year I ordered a new pMag with a wire set. Then I received a notice from them that some of the wire sets were shipped out with weak connectors that would not snap into place on the pMag or the plugs. After calling them, they had me send my set back in and I soon received a new set of plug wires at no cost. Give 'em a call, they're great to work with.
 
Be cautious about using a lubricant on plug boots. Although it tends to make them air tight and moisture proof, it can also allow the boot/connector assembly to rotate slightly on the coil post due to vibration...the boot doesn't grip the tower or plug as dry silicone would. I've seen some really worn connectors, as well as things like spark plug caps with grooves cut in them.

The p-mag coil is a Ford part. E-mag owners are unlikely to change it for the previous style, which is electrically equivalent, but for those going with an EDIS-base system, the early coil uses wire caps with positive retention.
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Just something to consider

Based on past input from the forum, I use Fuel Lube as a dielectric lubricant for Pmag plug boots and it is very hard to get them off and they are clearly moisture occlusive, just a thought.
 
Another Loose Lead

To add another data point, I had a Pmag lead fall off at the mag end on my new engine. Did not notice it because misfire was masked by the other Pmag firing the other plug. I also found a loose, but not disconnected lead on the other Pmag. I will be calling Emag about this. I believe my leads were made in the suspect time period.
 
Update

I contacted Brad at Emagair and explained my problem. He quickly agreed to send me two replacement wire sets at no cost. Because the coil ran for a while with the wire disconnected, he said the coil is now suspect and he is sending a replacement coil as well. Great customer service.
 
Did they indicate what the suspect time period was for the weak connectors? My P-mags are circa February/ March 2020.
 
Did they indicate what the suspect time period was for the weak connectors? My P-mags are circa February/ March 2020.

Here you go, straight from Emag service notes:

Plug Wire Terminal – Coil Connection

Importance – High.

Background: We have recent reports of certain ignition leads having reduced retention force at the coil termination on the back of the ignition. Ignition leads have a circular terminal with a dimpled spring steel retention band. The dimples in the band engage with grooves cut into the coil terminal post to provide a positive lock. Dimensional variations can reduce retention characteristics and potentially allow the lead to separate from the coil. Such occurrence would result in loss of plug firing of one and possibly two cylinders and possibly damage the coil. We have no such reports with spark plug terminations on the other end.

Identification:

The number of problematic terminations in this group is unknown. At time of posting, we have three instances (out of 175 sets) in the study group. Inspection is the only way to confirm proper fit
Starting: Harness lot number 653 (see printed sticker on outside of harness package) started shipping 2/25/19 with Invoice 8605.
Ending: Harness lot number 770 ended with invoice 8795 that shipped 5/6/19.
Harnesses shipping 5/6/19 (lot 770-A) and after have different coil terminals – identified by the shiny silver colored (steel) retention band. Earlier retention bands are black, but color alone is not a defining characteristic.
Inspection:

Test fit each coil terminal on a coil post.
As you push the circular terminal onto the post, you should feel and/or hear a series of distinct clicks as the retention band detente snaps over the post grooves.
Insertion and removal force less than 2.0 pounds could be considered problematic.
Action:

Replace Terminals:
Contact E-MAG to obtain approved replacement terminals and a terminal crimp tool (if needed). Parts will be provided at no charge – other than the cost of shipping. Make sure to specify if you need a 4 terminal set (one ignition) or an 8 terminal set (two ignitions).
See installation manual for instructions how to replace terminals.
 
Just like the bulletin states. My Pmags and wires were ordered in early 2019, the suspect period. They had the dark colored spring clips. The new ones are shiny silver. I put them on today and they definitely snap on more securely.
 
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