At 06:39 PM 4/29/02 -0600, Walt wrote:

Sometime ago someone posted ohm values for our plugwires. Little refresher here, what were they? Or what should they be? And coil wires?

The following is not my own words, but I would never doubt that it is the true gospel. Actually, the very first part of the first sentence could just as easily be attributed to me.... ;^)

" While I haven't actually checked the resistance on the 928 wires, the usual value for most plug wires is 2-3000 ohms per foot of wire. When they go bad, the resistance is almost always infinite (open circuit).

Wally Plumley " (Feb. 2002)

Distributor cap - 1k ohm
Rotor - 1k ohm
Spark plug connectors and lines - 3k ohms
Ignition coils:
Primary resistance of terminal 1 vs. terminal 15 - 0.4 to 0.7 ohm
Secondary resistance of terminal 1 vs. terminal 4 - 5 to 8.7k ohms


Uh, I have measured on my 1983. The wires are essentially 0 ohm. But there is a 3k resistor in the spark plug cap and the cap is even labeled "3k". Makes some sense when one thinks "Perfectionist Porsche Engineer" as this way all the plugs fire with exactly the same resistance rather than short wires with less and long wires with more.

Bought a generic set of non-resistor plug wires and spent many hours figuring out how to retrofit Porsche/Bosh ends. Made one perfect yellow wire with black ends to replace my worst wire. Then bought a proper set of black wires. My original wires were so bad that one could see the center conductor in many places. And the wires glowed blue at night with the engine running.

David Kelly N4HHE,


I had measured the wires on my 83, and found that the plug wires (complete with connectors on both ends) were all 3000 ohms +/ 200 ohms, and the coil wire was 1000 ohms. I didn't notice any discrete resistor in the spark plug cap. My wires say 'Bosch - 7mm - Silicone High Temperature' on them. Does this sound right for 'real' Porsche wires?

Eric Buckley