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ray_mcavoy · 03-15-2017, 09:23 PM

A Google search of Littlefuse 3961573 comes up with numerous hits indicating that it is a TCS relay.

TCS (Transmission Controlled Spark) is an early emissions system that was introduced around 1970 and doesn't show up on a lot of the wiring diagrams. In addition to the relay, the TCS system originally had a 2nd temperature switch on the engine, a switch on the transmission, and a solenoid valve plumbed inline with the vacuum hose going to the distributor advance.

Unless you have local emissions inspections that require you to have all that stuff hooked up, you can delete all the TCS parts and their associated wiring.

03-15-2017, 09:23 PM	#2
ray_mcavoy Registered User Join Date: Nov 2009 Location: Sherman, ME Posts: 2,354	Re: Littlefuse 3961573 A Google search of Littlefuse 3961573 comes up with numerous hits indicating that it is a TCS relay. TCS (Transmission Controlled Spark) is an early emissions system that was introduced around 1970 and doesn't show up on a lot of the wiring diagrams. In addition to the relay, the TCS system originally had a 2nd temperature switch on the engine, a switch on the transmission, and a solenoid valve plumbed inline with the vacuum hose going to the distributor advance. Unless you have local emissions inspections that require you to have all that stuff hooked up, you can delete all the TCS parts and their associated wiring.