Ignition Coil heating up when engine turns over , but does not start?

I replaced an ECM on a 1985 Mercedes 380 SL, the engine turns over, but does not start.The ignition coil becomes, hot, there appears not to be any fire?

The heating up of the coil could be the result of several problems. The coil could be shorted or the ignition module is continuously ‘on’.

To test the coil, disconnect all the leads of the coil. Connect the high voltage lead to a free spark plug grounded to the engine; connect the + terminal of the coil to the battery positive with a clip lead; attach another clip lead to the negative terminal; and stroke the other clip against a ground. If you do not get a spark, suspect the coil.

If the coil test okey, remove the ignition module and have it tested at a parts store. Alternately, you could try a new one and see if that stops the coil from heating.

Hope this helps.

It could also be that the line from the low side of the coil primary to the ECM is shorted to ground. An ohmmeter can find this.