How can I test the coil packs with a multimeter on a 2005 Cadillac deville northstar engine v8 with the coil packs being the white top coils.
Oct 5, 2026 at 8:05 AM
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MNELSON08
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25 POSTS
It’s a 4 pin coil packs
Oct 5, 2026 at 8:06 AM
STRAILER
✓Experienced Mechanic
55,588 POSTS
I would not rely on a conventional primary/secondary resistance test with a multimeter. These are electronically controlled coil/module assemblies rather than the older simple two-terminal coils. Each coil circuit has ignition voltage, ground, a PCM ignition-control circuit, and a low-reference circuit.
Oct 6, 2026 at 10:22 AM
MNELSON08
MEMBER
25 POSTS
So how do i test them? This is whats happening im getting a p0300 code random misfire, ive changed the spark plugs already. When starting the car it starts and then it shakes when in idle. It also will die at stop signs when driven. No other show up.
Oct 7, 2026 at 8:58 AM
STRAILER
✓Experienced Mechanic
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There is not a good way to test them unless you remove one side (4 coils) and test the output. This video can show you how.
How did it turn out do all of the coils have spark?
Oct 14, 2026 at 7:13 AM
MNELSON08
MEMBER
25 POSTS
No I’m askin do I test each coil or the whole rail output
Oct 14, 2026 at 9:59 AM
STRAILER
✓Experienced Mechanic
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You keep the coil pack connected and check the spark output, did you watch the video?
Oct 14, 2026 at 5:29 PM
MNELSON08
MEMBER
25 POSTS
Yeah it says unlock the safety lock on the coil pack so I test each connector to the coil pack. The connectors that connect to the top of each coil pack. Then it says to stick paper clips in the connector, how do I know which one is ground? It’s a connector with 4 female parts on it. (4 pin connector)
Oct 15, 2026 at 1:18 AM
STRAILER
✓Experienced Mechanic
55,588 POSTS
No, you will be checking he coil output not inputs. Please go over this guide instead.