What is the resistance specification for Bosch coil? - PeachParts Mercedes-Benz Forum

Marrs · #1 03-26-2012, 04:29 AM

I want to bench test my Bosch coil (part # 0 221 102 004) but most of the label is missing and I can't find the info online. What should the two values be from each test point, ie: posts and center?
Also, what is the correct ballast resistor for this coil (ohms)?

Better yet, what combo coil/resistor (part numbers or specs) should I use as an upgrade when I visit the shop today?

Marrs · #2 03-27-2012, 11:50 AM

I'm actually replacing with new to avoid potential issues.
Was suggested to me by a resident expert to replace with Bosch 0 221 119 030 coil and Bosch 0 227 901 014 ballast resistor.

sjefke · #3 03-27-2012, 11:55 AM

Have you considered a Petronix upgrade? Putting an Ignitor module in the distributor and a matching Flamethrower coil instead of the Bosch coil might just be a bit more expensive, but probably simplify your system and maintenance.

Bert

Palolo · #4 03-27-2012, 01:00 PM

I think Marrs already has a Pertronix, unless you're referring to some other Pertronix part... Car wants to stall at idle, more details included

Sorry, side comment in this thread: If one doesn't have points (by whatever alternate solution of Pertronix, Crane or 123) can one bypass the ballast resistor for more spark? And keep stock coil?

Or should one get a new/different coil when bypassing the ballast resistor if running a points-less ignition?

sjefke · #5 03-27-2012, 01:57 PM

As far as I know, the Ignitor or any other distrubor mod only affects the firing (from a timing perspective) of the coil, NOT the coil's output in terms of volts. If you want to boost/change the spark amount (Volts), then you do need to mod the coil and/or its power circuit, but NOT the points/pointless activation mechanism.

If he already has Petronix module, then I would just put in a Flamethrower coil and be done with the resistance measuring stuff. Only problem is tachometer if he has one. I still need to fix that on mine.

Bert

Marrs · #6 03-27-2012, 11:59 PM

Hi, yes I do already have a Pertronix that the PO installed. I prefer the Bosch coil and resistor since that's what's in there now, just for sentimental reasons I suppose to keep it looking relatively stock under there, tho I am no stickler for originality on a driver. Since there really is no visible parts on the Pertronix right now it still has the "old timer" vibe when I pop the hood (ie: nothing is shiny on mine lol). I don't mind having a ballast resistor at all and in fact feel it's a good bet having a separate unit since it's not like they really ever break, so this will likely be a one-time deal for me. Heck, the present coil lasted 50-years exactly!

Of course there is no reason not to change to the full modern system if it suits you.