View Full Version : 350 Lockup Transmission

04-06-2000, 11:04 PM
Has anybody had any problems with getting a signal to the lockup solenoid on a 1981 350 lockup transmission? <br>Mine is in a 1981 2WD Blazer and the lockup works on the Tranny if a signal is sent from an external source but I don't know where to check to see why the original sending source isn't sending a signal.

04-07-2000, 05:13 PM
Better go and check out a service manual at the library. I know that TCC lock up usauly has a vacuum solenoid and a cut out switch on the brake pedal. Checking the book should show you wath you have.<br>Good Luck

04-07-2000, 06:13 PM
It's actually an Electronic solenoid not vacuum...thanks for the Library advise

04-07-2000, 07:29 PM
The solenoid is electric, but there should be a vacuum switch under the hood, on the left side of the firewall, with one vacuum line and two wires. Atleast my truck has one there. I have a little different system. but I remember seeing them there. If I remember right they would inhibit lockup untill the engine warmed up. there was a TVS in the intake that controlled it. It was supposed to improve cold drivability. I have mine bypassed. I have never had a problem with the way my truck shifts. but that is what it is for.