Small Engines (Lawn Mowers, etc.): ariens interlock module, thanks wade, mytractorforum

Question
QUESTION: Hi Eric,
A friend of mine has an interlock module (part # 53123600) on an Ariens model 931023 garden tractor.  The 4th and 5th diodes from the top have been corroded and cannot be read as to their value.  Can you provide this info and which way the diodes are put on the board?  Is there a schematic available for this board?
Thanks, Wade

ANSWER: I checked the online parts and all they list is the module part number.

http://partsradar53.arinet.com/scripts/EmpartISAPI.dll?MF&app=ARNC531&lang=EN&TF


Did you ohm the diodes to see if they are still good?  If you can ohm them then you can tell which is the cathode and which end is the anode.

It must be a rare part, we have never sold one, none on E-Bay and the online parts don't list a price.

Have you tried the antique tractor sites such as this one:

http://ytforums.ytmag.com/viewtopic.php?t=320243

or

http://www.ssbtractor.com/wwwboard/messages8/1664.html

Or

http://www.mytractorforum.com/showthread.php?t=62728

Do you know the diodes are actually bad such as the leads not connected?
Let me know.
Eric

---------- FOLLOW-UP ----------

QUESTION: The module is available from several online dealers.  However, it is pricey.  Anywhere from $138 to $160.  
No, I did not ohm the diodes.  Don't know how to tell the cathode from the anode.  Maybe you can help me with that one.
All that is left of the 5th diode is the wires.  The 4th one is still there but in very poor condition.  It is badly corroded.  The leads are still connected to the board on both of these diodes.
Thanks,
Wade

Answer
Google "how to check diodes", you will get lots of sites.

As for replacing the diodes I would recommend heading to a local Radio Shack and purchasing some diodes that are at least the same physical size or larger.  Diodes are cheap compared to the replacement module so you really have very little to loose.  I'm betting the diodes pass very little current, most likely they just all the circuit to complete to start the engine.

As long as you get the same size or larger physical size diodes you should be fine.  I'd definitely give it a try.

Also, check the other diodes on the board for part numbers.  Are they all the same?  If so google the diode part number and I'd bet the other diodes are the same ones.

Can you send a picture of the board?
Eric