Coils tested with multimeter... Are these readings ok?

[dkcaims]

90 C4
Stock black Bosch coils (made in spain)

1st Coil = Primary .001 (gauge set to 2k) and .9 (gauge set to 200)
Secondary 6.18 (gauge set to 20k)

2nd Coil = Primary .001 (gauge set to 2k) and .9 (gauge set to 200)
Secondary 6.08 (gauge set to 20k)

Thanks for your help.
Derek

[steely]

It sounds normal according to this:
Carrera Coil resistance values?
Porsche 911 Carerra service manual, group 280, page 9 is missing the table for ignition coil testing. The information is as follows:

Primary resistance:
Test between terminals 1 and 15
Value: 0.4 to 0.7 Ohms

Secondary resistance:
Test between terminals 4 and 15
Value: 5.0 to 8.7 k Ohms

credit to miskar

Derek, you might try reading the primary on a lower range if you have one, but the 0.9 is nominal according to the info above.
(you showed that you read 1 going to .9 when you went from the 1000's to the 100's range which is still ok)

[dkcaims]

Originally Posted by steely

It sounds normal according to this:
Carrera Coil resistance values?
Porsche 911 Carerra service manual, group 280, page 9 is missing the table for ignition coil testing. The information is as follows:

Primary resistance:
Test between terminals 1 and 15
Value: 0.4 to 0.7 Ohms

Secondary resistance:
Test between terminals 4 and 15
Value: 5.0 to 8.7 k Ohms

credit to miskar

Derek, you might try reading the primary on a lower range if you have one, but the 0.9 is nominal according to the info above.
(you showed that you read 1 going to .9 when you went from the 1000's to the 100's range which is still ok)

Thanks Dan... Taking some pics now of my meter and readings.

[dkcaims]

Here are the readings on across the primaries... note the 3 different settings on the meter.
Thanks again for your help.

[scarceller]

If you simply want to know if the coil can fire you can bench test them carefully, with a 12vdc power source like a spare battery. Here's how:

1 - connect a spare spark plug wire to the output of the coil and a spark plug on the other end.
2 - get a 6" alum or steel flat stock to create a ground bar and connect this ground bar to the Battery '-' with alligator test lead.
3 - Connect the coil '+' lead to the battery '+'
4 - Clamp the spark plug to the ground bar with vise grip or any type of clamp
5 - connect another test lead to the coil '-' side
6 - here comes the fun part, now with insulated electrical pliers hold the other end of the '-' test lead and tap it against the test bar (or the battery '-') and hold it for about 1 or 2 seconds and release it. The Spark plug will fire.

What your doing is simply running the coil Old School like a 'Points' system does. When you hold the coil '-' side to ground current flows through the primary coil and charges the secondary side. Then when you remove the coil '-' from the ground point the coil's charge field collapses and arcs across the spark plug.

But your resistance values tell me the coil is most likely OK, they seem in spec with the specs posted above.

[dkcaims]

Originally Posted by scarceller

If you simply want to know if the coil can fire you can bench test them carefully, with a 12vdc power source like a spare battery. Here's how:

1 - connect a spare spark plug wire to the output of the coil and a spark plug on the other end.
2 - get a 6" alum or steel flat stock to create a ground bar and connect this ground bar to the Battery '-' with alligator test lead.
3 - Connect the coil '+' lead to the battery '+'
4 - Clamp the spark plug to the ground bar with vise grip or any type of clamp
5 - connect another test lead to the coil '-' side
6 - here comes the fun part, now with insulated electrical pliers hold the other end of the '-' test lead and tap it against the test bar (or the battery '-') and hold it for about 1 or 2 seconds and release it. The Spark plug will fire.

What your doing is simply running the coil Old School like a 'Points' system does. When you hold the coil '-' side to ground current flows through the primary coil and charges the secondary side. Then when you remove the coil '-' from the ground point the coil's charge field collapses and arcs across the spark plug.

But your resistance values tell me the coil is most likely OK, they seem in spec with the specs posted above.

Thank You !!!