please help - Ignition testing

[valerio]

I did a search but could not find the answer I was looking for.

I am looking for the procedure on how to bench test the ignition transistor module, I think that it might be the culprit of my lack of spark.  I have the module out of the car, but before I spend the money on a replacement I would like to be able to test it.

Thank You

[jeffc280sl]

Hope this helps.

Download Attachment: 15-20B.pdf
124 KB

Jeff C.
1970 280SL 4-speed

[Peter van Es]

I've uploaded a new pdf in Jeff's post so that the details are more visible. So please click on the link in his post again.

If ever you feel the need to post a larger file, or picture, which does not come out properly with the 80K limitation, you can mail me at admin@sl113.org

Include the file that you'd like included and the URL of the topic ID (just cut and paste the line in the browser URL box into your e-mail).

Peter

Check out http://bali.esweb.nl for photographs of classic car events and my 1970 280 SL

[mdsalemi]

In the case that the OEM Bosch module is proven to be defective, rather then give yourself a coronary and or waste a lot of time trying to find a rare and expensive replacement, the Crane unit can replace the Bosch module.  In addition, either the Crane or the Pertronix can be a relatively inexpensive replacement.

I've had both, and run the Pertronix today.

Michael Salemi
1969 280SL
Signal Red 568G w/Black Leather (Restored)
President, International Stars Section
Mercedes-Benz Club of America

[valerio]

First of all thanks to all for the replies.

secondly I want to verify that b the crane xr700 is the ignition module for this car and that it "completely bypasses" the transistor.

[jeffc280sl]

You're welcome.  I have the Crane XR-700 in my 1970 280SL.  It works fine.  You can run a search on it and get comments from others.  It completely replaces the MB box located under the battery.  In fact I put the Crane box, which is smaller, in the same location.  There are some tricky parts to the install.  If you need help let us know.  Here is a pic of the optical trigger.

Jeff C.
1970 280SL 4-speed

Download Attachment: crane 1a.jpg
20.9 KB

[mdsalemi]

Valerio,

Yes it is the XR700 Crane model...I have had both this Crane and the Pertronix in my car, a 1969 with the -050 distributor.  Both functioned identically in my opinion.

One major difference is in the install: the Pertronix is quite a bit easer to install and requires no modifications; just a small filing of an internal part.  The Pertronix has no external box.  The Crane is a bit more complex.  Both companies have excellent technical support.

I had the Crane for 5 years of flawless operation; however from the git-go it was improperly installed--not the fault of Crane but of the installer.  They used an optical wheel too large for the distributor which caused them the remove the pivot pin, thus forever condemning the distributor to Crane.  I do not believe they had to do this.  The problem with an optical wheel too large is that after 5 years of flawless performance it decided to contact the wires inside and this caused engine dying.

The Pertronix is a much neater installation.  I have seen no functional difference between the two.  I idle at a smooth 750-800 RPM, and run way up past 5,000 RPM with no issues.

Purists will tell you to stick with points, and what if you get stuck somewhere?  To that I say, at about $100 it is cheap insurance to keep a spare Crane or Pertronix in your tool kit the same as you'd have set of points.  Once you have the spare of course, you'll never need it.

Michael Salemi
1969 280SL
Signal Red 568G w/Black Leather (Restored)
President, International Stars Section
Mercedes-Benz Club of America

[Naj ✝︎]

Here's a Crane installation with the pivot pin in place:
Just use the smaller of the two six slotted wheels.




Thanks to Peter van ES for today's picture loading lesson [:p]
naj

68 280SL

[J. Huber]

Hey Naj. How come your vacuum device is on the radiator side of the diz. Should mine be?

James
63 230SL

[Cees Klumper]

Naj - do you still have that condensor that's stuck to the side of the distributor body hooked up? I am pretty sure that I was able to take it off when I installed the electronic ignition on my car.

Oh, and on my car also the vacuum unit is in the same spot as Naj's.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[Naj ✝︎]

Hello James,
 

quote:Hey Naj. How come your vacuum device is on the radiator side of the diz. Should mine be?

No, James, this is the 051 Vacuum retard on a 280 SL. Yours should be pointing to the firewall  

Hello, Cees,
 

quote: Naj - do you still have that condensor that's stuck to the side of the distributor body hooked up? I am pretty sure that I was able to take it off when I installed the electronic ignition on my car.

I've left if there in 'case' I have to put the points back on the roadside. No, its not hooked up. The points and other bits are under the suspension cover!
The theory is: If you're prepared for it, it might never happen  :?:

naj

68 280SL

[J. Huber]

Thanks Naj. I noticed the illustrations in my workshop manual have them in same place as mine...

James
63 230SL

[valerio]

I had the mechanic test the box and he says that its fine, but the car still won't start, the crane is on its way but will take a week before it gets to me.  This all started after I blew the fuse #2 because of a short in the cigarette lighter. Has anyone ever heard of the cigarette lighter causing all these problems?

[jeffc280sl]

Sorry to hear about your problems.  Fuse 2 serves the combination switch, horns, wiper and cigar lighter.  Nothing to do with the starter, ignition etc.

You say there is no spark.  Have you verified this by pulling a plug wire off and holding it close to a ground to see if you get an arc while cranking the engine?  How about the other fuses?  Starter lock out? Do you have a wiring diagram?



Jeff C.
1970 280SL 4-speed

[seixever]

Sometimes the problem can be the fuses box: on my 230 I found all the fuses contacts disconnected where they are fixed in the fuses box: the voltage enters but not goes out!