TECUMSEH 35135/35135A Resistance Specifications- electrical drawing/schematic

[pappabear]

Does anyone have access to the resistance specifications (primary and secondary ohms) for the Tecumseh 35135/35135A Ignition Module ?

How about an electrical schematic/drawing showing winding attachment points to the laminate frame, kill tab and high tension lead?

I researched the ITC4002 (dbelectrical) part which is made in Argentina by DZE : the factory number there is BEL10213. I e-mailed them requesting same however I don't expect a response. I don't know why these manufacturers aren't required to provide performance values before being allowed to sell these items.

Part number also crosses to:
PIC 9900-3112
EMS:TCC-101
Stens 056-126

Thanks.

 

[Rivets]

There are no published resistive values for CDI modules. The capacitors and sensors are located under the protective coating, with no external test points. Simple test experienced techs use, is to remove the kill wire and check for spark. No spark means replace the module.

For those who understand electrical terms, page 63 of this manual will show you what's inside.

http://www.mymowerparts.com/pdf/Tec...P-4-CYCLE-L-HEAD-FLAT-HEAD-ENGINES-692509.pdf

 

[motoman]

If you are remembering the good ole days of coil fired ignition where you could check for "opens" or high resistance due to corrosion , this does not apply to the "modules."

 

[pappabear]

Hey Rivets and Motoman,

Thanks for the RSVPs and the link to the manual- pg 69. I read through it and the diagram was spot on what I was looking for. I wish that I'd looked there first but was a bit more focused on the parts vendors supplying the manufacturer's datasheet.

Actually understanding the electronics function and circuit construction was my end goal and I accomplished it after a few hours of looking. Now I know the HOW it works from the engineering perspective now. I'll share the best link that I found wherein the author does an outstanding circuit function video of the schematic. It's for a scooter CDI but works equally well for this ignition module (it bears the Briggs and Stratton Bowtie impression).

Here it is: https://www.youtube.com/watch?v=0yK3Opq_i0M

I contacted several supply sources and none could supply the necessary values or technical data. By surprise, the manufacturer in Argentina did RSVP with a value for the secondary of 4450 ohm +/- 10%. They said I could not read the primary value due to the front end electronics. They were right about that, however I did get a DC resistance measurement- I just didn't know what I was "seeing" in the circuit.

The trigger coil, SCR, diodes and capacitor would give errant readings with a DVM or VOR meter. My faulty unit measured 272 ohms from Laminate frame to kill tab, 5.67 Kohm from Laminate frame to Plug wire terminal, and 5.94 Kohm from kill tab to Plug wire terminal. If you do the math it adds up like I'm seeing the primary and secondary in series. 0.272 + 5.67 = 5.94 (Kohm). For grins and giggles I'll measure the new module tomorrow when it arrives and confirm what the factory engineer said in e-mail.

It got me curious about the method of construction too. I might have to soak the old one in acetone to dissolve the encapsulant potting material. That would be the best way to demo these to new technicians in training. That way they'd have a great mental picture of how its made and how it works. But then again Motoman has be nailed- I'm old school.

Cheers Guys! PB Out.

 

[pappabear]

Hey Guys,

Status update. I recieved the new ignition module and installed it after first performing DC resistance measurements.

Here's what I measured on the new unit.

Laminate frame (ground) to sparkplug terminal: 4450 ohms
Laminate frame (ground) to kill tab: 589 ohms
Kill tab to sparkplug terminal: 5030 ohms

I have spark now. Fired her up, readjusted the fuel air and bowl screws and she's a workhorse now! Happy DIY'r.

Here's the failed unit readings for comparison from my earlier posts:

Laminate frame (ground) to sparkplug terminal: 5940 ohms
Laminate frame (ground) to kill tab: 272 ohms
Kill tab to sparkplug terminal: 5940 ohms

There's a pretty significant % difference between the new and old readings. Now, why the manufacturer's cannot supply a measurement value with tolerances I'll never know. No wonder no one will guarantee electrical parts. You don't know if it is good or bad out of the box because you cannot test it before installing it. Now if you install it you bought it- good or bad! what a racket!