Actually a vacuum switch. Switch location depends on the distance between the pump and the reservoir. A length of pipe or hose from the pump to the reservoir can reduce or have less vacuum. So it's best to have the switch as close to the wiper motor as possible. It's not practical to mount a switch under the dash so Trico made it part of the assembly that mounts to the engine firewall (see picture).
The Electro-Vac doesn't have much of a reservoir and the switch is incorporated. It assists or adds to the manifold vacuum to keep an even vacuum for the wipers.
Last edited by buoymaker; 02/22/20228:22 PM.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
