[TR] A type overdrive solenoid problem?

[Greg Gelhar]

Bud, can you measure the voltage at the solenoid connection with the 
solenoid in the circuit? It is possible to measure the correct voltage at 
the disconnected wire because the meter does not load the circuit down. If, 
with the solenoid in the circuit, you do not see the correct voltage, then 
there is a high resistance connection somewhere to the solenoid.


Greg G.
Osseo,MN


----- Original Message ----- 
From: "Bud Rolofson" <levilevi at comcast.net>
To: <triumphs at autox.team.net>
Sent: Wednesday, October 03, 2012 10:49 AM
Subject: [TR] A type overdrive solenoid problem?


> The OD on my TR6 stopped working so I did the trouble shooting process
> in Dan Master's electrical manual and found I have voltage all through
> the circuit all the way to the bullet that connects the (yellow with
> purple stripe) wire to the solenoid. The voltage can be switched on
> and off with the OD selector switch on the column so everything works
> up to the point where it connects to the solenoid. But the solenoid
> doesn't engage.
>
> So the solenoid is bad right? What has me stumped is that the solenoid
> will operate if I hook it directly to an extra battery that I have.
> Why would it work with 12 volts directly but not 12 volts through the
> circuit? I even swapped out another solenoid from another A type OD
> and that one does exactly the same thing. Works with a direct hookup
> to a battery but not with the circuit. I checked to see if the
> solenoid is grounded and it has continuity according to my meter.
>
> With the solenoid hooked to the system when I engage the OD switch the
> voltage goes as far as the bullet but doesn't register at the
> solenoid. It's as if the solenoid "clogs" the flow of the voltage.
>
> What could be causing the solenoids to work with a direct battery
> (voltage measured at 12.11) but not with the circuit (voltage measured
> at 12.75)?
>
> I'm stumped. How can both solenoids work in one situation and not the
> other?
>
> Thanks
> Bud Rolofson