# Variance in Primary Ignition Coil Resistance Measurements / Time to Replace Coil? **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** chevrolet, suburban\ **Created:** [March 8, 2017, 4:51pm UTC](https://community.cartalk.com/t/variance-in-primary-ignition-coil-resistance-measurements-time-to-replace-coil/100955 "2017-03-08T16:51:34Z")\ **Posts on this page:** 6\ **Page:** 2
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [March 8, 2017, 10:25pm UTC](https://community.cartalk.com/t/variance-in-primary-ignition-coil-resistance-measurements-time-to-replace-coil/100955/21 "2017-03-08T22:25:50Z")
How expensive is a new coil? How old is the cap, rotor, plugs, and wires? Maybe a ‘tune up’ is in order. ---
**Author:** ![southsidesmoka](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/southsidesmoka/32/6736_2.png) [@southsidesmoka](https://community.cartalk.com/u/southsidesmoka)\ **Post date:** [March 8, 2017, 10:31pm UTC](https://community.cartalk.com/t/variance-in-primary-ignition-coil-resistance-measurements-time-to-replace-coil/100955/22 "2017-03-08T22:31:01Z")
The new coil is about $35 - $40. The current coil, rotor and cap are approximately three years in age. Plugs and wires were installed yesterday. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [March 8, 2017, 10:38pm UTC](https://community.cartalk.com/t/variance-in-primary-ignition-coil-resistance-measurements-time-to-replace-coil/100955/23 "2017-03-08T22:38:41Z")
Have you checked the battery cables for internal corrosion or breaks? May be easier if you can check the voltage at the starter when you try and start without jumping. ---
**Author:** ![southsidesmoka](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/southsidesmoka/32/6736_2.png) [@southsidesmoka](https://community.cartalk.com/u/southsidesmoka)\ **Post date:** [March 9, 2017, 8:20am UTC](https://community.cartalk.com/t/variance-in-primary-ignition-coil-resistance-measurements-time-to-replace-coil/100955/24 "2017-03-09T08:20:57Z")
My battery cables are the original, 8-gauge factory cables. They appear to be in good condition. However, on a 99 model year, things have had some time to age and run through their life cycles. Perhaps replacing the battery cables with 4-gauge cables, replacing the ignition coil, ICM, distributor rotor and cap will fix my issue - a “tune-up”, indeed, when paired with the spark plugs and wires done on Tuesday. I seriously believe this problem to be electrical in nature. The engine only has approximately 115,000 miles on it - it’s a rebuilt Jasper engine installed four years ago - engine number three for The Bus. Any thoughts? Any advice? Thank you, all, for your words of wisdom. They are appreciated. 😁 - southsidesmoka ---
**Author:** ![southsidesmoka](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/southsidesmoka/32/6736_2.png) [@southsidesmoka](https://community.cartalk.com/u/southsidesmoka)\ **Post date:** [March 9, 2017, 3:58pm UTC](https://community.cartalk.com/t/variance-in-primary-ignition-coil-resistance-measurements-time-to-replace-coil/100955/25 "2017-03-09T15:58:49Z")
An Update: Unfortunately, it’s not the ignition coil. Replaced to no avail. 😠 She’s simply not getting a strong electrical signal…why, I am not sure; but, I [I]shall[/I] find out and repair it. 🤔 Open to ideas. Going to replace battery cables. Thank you to all for reading and for any help. Afternoon Update: Turns out every distributor cap tower contact and the center contact are all covered with what resembles battery acid build-up. Not sure what it is, but, “there’s your problem”! Headed to parts store now for new distributor cap and rotor. Any explanation as to how this strange situation happened? I would suspect carbon build-up…but the matter the contacts are covered in is thick and white. Still having problem after replacing the distributor rotor, distributor cap, ignition coil, spark-plug wires and spark-plugs themselves! She cranks but WILL NOT start without a boost. Help, [I]please[/I]! And in the end: I drained the battery below the necessary 12.5 to 12.7 volts needed to turn the engine over while trying to start her. After a few hours on a charger, she’s able to start on her own. **The problem was the corrosive build-up on the internal tower connectors of the distributor cap**. Learned about the cause of the problem from a GM Service Bulletin. There’s improper ventilation in the distributor cap on some older models which leads to the build-up. Maybe I can save others some trouble. Maybe not. Anyhow, thank you all for your assistance. - southsidesmoka ---
**Author:** ![TwinTurbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@TwinTurbo](https://community.cartalk.com/u/TwinTurbo)\ **Post date:** [March 9, 2017, 5:47pm UTC](https://community.cartalk.com/t/variance-in-primary-ignition-coil-resistance-measurements-time-to-replace-coil/100955/26 "2017-03-09T17:47:07Z")
Sounds like someone applied a liberal amount of dielectric grease… [Previous page](https://community.cartalk.com/t/variance-in-primary-ignition-coil-resistance-measurements-time-to-replace-coil/100955.md?page=1)