Hi Steve and other ignition expert, I have 2 topics

1) In the EZL data page (94) of the Mercedes 103 manual, it shows the resistance between primary terminal 1 and 15 should be 0.30-0.60 ohm. But in next page on how to test the ignition coil, it shows if the resistance is not within 0.36 and 0.40 ohm, replace the coil. My first question is which set of spec. is right? If the 0.36 to 0.40 is right, why such a tight tolerance? my coil shows 1.1 ohm, it still runs, should it be replaced? With 1.1 ohm, does it mean I am getting a weaker spark due to higher resistance?

2) Many members toyed with the ides of using ACCEL 140008 coil, the primiary resistance of that coil is 0.50 ohm. Can this coil be used? They use + and - rather than 1 and 15 on the terminals, can you tell me how Mercedes corresponce

Thanks

With similar resistance you can probably use a diferent coil. I don't think you will save much money and there is no need for anything over the capability of the original good working Bosch coil.

Besides they look so tacky under the hood.

As to the resistance and whether you are out of spec. This is not a good way to test a coil for capability. An engine uses what it needs in the way of voltage and coils usually make about 2-3 times what they need. Testing with a secondary ignition analyzer can give the total output capable and that which is necessary. That is how I test.

Terminal 1 is the trigger and 15 is the power side.

Donnie, please clarify
 

Hi Donnie, does it mean + is power, - is trigger?

Thanks