Minor repair of T-L control box.

Posted by Randy Berger On 2013/5/14 1:21:50

Best Other's T-L system was not working properly, or sometimes not at all.
After checking all the wiring to ensure that was not the problem, I removed the control unit
from the frame and opened it up. Cursory examination did not disclose any problem.
I hooked a jumper from Ground (earth for Mal) to the body of the unit and ran a jumper
from the positive battery terminal to the Green (center) terminal.
This allowed me to manually move the control arm and observe how the contact points
were functioning. The bi-metallic arm was barely moving, and would not close the back
(down) relay at all. After careful examination I finally saw that the bottom wire winding
on the bi-metallic arm was not fastened to the post properly. The nichrome wire is attached
by some type of glue as it cannot be soldered directly. I drilled a small (1/16) hole in the
post and after skinning off the fine insulation on the wire I threaded it thru the hole,wrapped
it around the post and shoved it thru the hole again. Then I soldered the hole shut. This will hold the wire securely and allow it to make good electrical contact.
I used a small screwdriver to tighten down the gap to hold the Douglas connectors very snugly.
Testing function after fixes complete was successful. The bi-metallic arm moved and made contact after 6+ seconds and closed the proper relay. I'll install it tomorrow - I'm going to bed.
Clicking on the pictures will give you a better view.

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