[TR] Problem with J-type overdrive blowing fuses

[greg at gelhar.com]

> Greetings:
> I recently installed a J-type overdrive in my TR6 and after 100 or so
> kms, it started blowing fuses. Sometimes right away and sometimes
> shortly after.
> I put the overdrive system on a separate circuit  and it acted the same.
> Could it be the solenoid acting up and drawing too much current or is it
> usually a short in the switch or wiring system?
> Allan Reich
> Vancouver Canada
> 1975 TR6 CF30255U (and occasionally "O" when it works!)
>
>
Its good that you supplied the overdrive with a fused circuit. The
overdrive solenoid has two windings. A heavy 'closing' coil and a lighter
'holding' coil. The heavy coil draws 18 to 19 amps and is only in the
circuit momentarily. The solenoid should close with a surge of current and
the ammeter should show arround 1 to 1 1/2 amps.  That shows the 'holding'
coil is working and the 'closing' coil has been switched off by the
solenoid plunger action. The plunger switch is under the top cap of the
solenoid.

Without your fuse, the solenoid won't last long if the switch fails to work.



Greg G.
Osseo, MN