bosch red coil how many ohms?

[Dave]

Anyone know?  It is actually brand new with red label

[280sl1968]

Needs a separate 1.8 ohm ballast resistor.

David

[Benz Dr.]

The black coil is about 13 KV and the red one is about 26KV.  So, following simple math, the black coil uses .9 ohm ballast resistor and the red coil which is twice the voltage, uses twice the resistance on the ballast resistor at 1.8 ohms.

[Dave]

The car now runs great thanks to you and others who helped me get the timing right.  Just got back from 45 minute test drive - wow!  I can't figure out if the ballast resistor should left on.  It runs great with it on now but i dont know if i should take it off.  051 distributor red coil 1.9 resistor

[Benz Dr.]

If you have the orginal point set up you better leave the resistor in place or it will damage the points and can damage the coil if the ignition is left on.

[Dave]

Newly installed pentronix thats why i dont know if resistor should be used  or  bypassed

[Benz Dr.]

OK, in that case you may not need it.  The ballast resistor lowers primary voltage going into the coil and across the points.

[rogerh113]

Again, I've been using my Pertronix for over a decade with the ballast resistor in place, and never had any issues.  With a red coil, if anything you would require a resistor with higher ohms. 

It sounds like your car is running great and you are pleased with the performance.  What do you figure the downside is of leaving the resistor in place??   With the car running well, I would be more concerned about removing the resistor.  A really nice thing about Mercedes, particularly the older ones, is once you fix it you generally don't need to keep poking at it.  Generally that does not make things better, although it may provide entertainment value.  Maybe a good time to move on to something else on the car that needs attention and just monitor the performance.  My guess is that the Pertronix will just keep humming along with no troubles. 

Regards -- Roger

[1mastertech]

Across the primary side of the coil, terminals 1 to 15, measures 1.5 ohm.  I have 2 new 'red' coils on the shelf and I measured them both.  The same.   This coil has Bosch number 0 221 119 030 and Mercedes number 000 158 49 03.   Terminal 4, the secondary circuit, to either terminal 1 or 4 is open.  Don't understand where the 27K ohm primary circuit reading in an earlier post came from.  Did I misunderstand the question?

[Peter van Es]

26KV not 27 K Ohm...

[Benz Dr.]

26KV not 27 K Ohm...

Right.  The red coil produces roughly 26KV ( kilo-volts ) or 26,000 volts. There is little amperage in a 12 volt ignition system so that's why it will normally only hurt and not kill you. If you happen to have pace maker for your heart or heart trouble, you should stay away from ignition systems.

[dante53]

My new Bosch red coil measured 1.4 ohms