MSD Magnetic Pickup

Just wondering if the MSD Magnetic Pickups are know to fail.

Spring has sprung and Ryan and I have been driving the Cobra. It was running great until yesterday. No spark. After doing the various recommended checks, traced the problem to the magnetic pickup in the disbtibutor. Instead of a resisteance of 400 to 1300 ohms across the pickup terminal it was showing several hundred thousand ohms.

The car is two years old and has 5500 miles. Seemed odd it would fail. I assume it is just a coil of wire sealed in a case - so what's to break?

Did notice that the bracket that holds it down was covered with a layer of rust. Everything else inside the dizzy looks good.

So just curious. Anyone else had a similar experience? Is there a reason this part would fail so soon?

HI Chuck,

I've not seen a lot of failures in Mag pickups, but that doesn't mean that it could not happen. Actually I've only seen one that I could recall and that one was gapped wrong using a steel feeler gauge which magnetized the coil's center. High humidity takes it's toll on electronic parts - particularly coils that may not be perfectly sealed. If the pickup coil has attracted any moisture inside, it could have corroded. Or the connection of the harness to the coil itself. Normally those things are well potted (sealed)..

Randy:

You raise a good point. When gapping the replacement need to use non steel feeler gauge. Thanks for the reminder.

The wire that wraps the field coil is a very very small and if one strand fractures you will have an open circuit creating the infinate OHM reading you obtained. However overall they are quite reliable. That's the reason they use them in the primary circuit instead of points, along with the fact there is no wear to contend with. Black or white, no gray area here.

CESLAW said:

Randy:

You raise a good point. When gapping the replacement need to use non steel feeler gauge. Thanks for the reminder.

Click to expand...

Either Non-Magnetic (some are stainless) or Brass.

Went shopping for you and found this;

While we find your parts, please enter your ZIP Code at CSK Auto

Powerbuilt Tools Feeler Gauge Set: 6 Blade Non-Magnetic
Part Number: 648519

Randy:

Thanks for the info. Appreciate you shopping for me. . . . . .

Recived the replacement MSD Magnetic Pickup from Jegs today. Replacing it was straightfoward. But the directions said nothing about the gap. I gapped it at .025 (other posts had suggested between .025 and .030) using a brass feeler gauge (thanks Randy). Works just fine. It still seems odd to me that it would suddenly fail after only two years and 5500 miles. A pic of the old and the new side by side is attached.

While we were at it the distributor cap and rotor were also replaced.

Time to get out and DRIVE!!!!