View Full Version : Tk Magnum Whisper

29-12-2006, 12:53 AM
Hello All,

Have a TK MAGNUM WHISPER MPVI. When the unit starts the starter stays engaged for a couple seconds after start up. The 8S wire stays hot when the starter stay in (obviously), but here's the thing. What is the mirco looking for to know that the engine is started and drops out the start relay on the board? I know that on the Carriers its the D+ wire off the voltage reg on the back of the alt, but on a TK?? Thinking back in time i would say that its the rpm sensor. Its operation is ok (voltage ac good) and the micro display accordingly. Yet the mirco still grounds the relay after start up. Perhaps a micro glitch?? Bad relay board?? Since this thing is a MAGNUM i don't have anything around handy to just try out. Any thoughts out there?? The realy is ok.

I want Cycle Sentry II back, maybe a UE or two and possibly a Mercedes or Perkins to work on.



29-12-2006, 04:41 PM
Hi ReeferMadness,
we don't have Magnums in Europe, but for similar unit with MP-VI (older SL-400) manual states that:
The flywheel sensor is a proximity sensor that generates a pulse as each flywheel tooth passes the sensor. The microprocessor counts these pulses and performs the math necessary to convert the pulses into engine rpm. The flywheel sensor FS1 circuit is a digital input to the microprocessor. FS2 is a device ground. The sensor is not polarity sensitive.

Could a dirt in a sensor and/or flywheel cause any problems? Missing or bad tooths on the flywheel?
Also wire "W" from alternator is providing an ac voltage to the MP and considering the clutch engages when engine speed reaches about 400 rpms (= alternator starts to rotate) is that signal delayed from some reason?
Hope this gives any help..


29-12-2006, 07:27 PM
Make sure the flywheel sensor is clean and adjusted correctly. Check the board and make sure all the tracings look good, no burns, arcs, etc.

30-12-2006, 05:30 PM
Nova, thanks for the info it sounds like the flywheel sensor over there is the same as here. Generates ac voltage. The sensor is well within range voltage wise and the micro is reading correct rpm. I will pull the board down when the unit comes back. Burnt or corroded relay boards generate enough headaches. People swap the reefer from one trailer to another and leave the mount tab open..... road salt and snow gets directly on the board.

Thanks for the Input.


06-01-2007, 08:16 PM
Tried another realy board and electrical connections. has to be in the micro.