Whelen 295HFS4 progressive slide switch?

Discussion in 'Q&A: Audible Warning Help' started by TheHealer, Feb 19, 2017.

  1. TheHealer

    TheHealer Member

    Is it possible to modify the slide switch to be progressive? I have three other trucks with Whelen controllers with progressive slides and would like to have this operate the same for continuity. Bought vehicle used so didn't have a choice. Thanks!
  2. wfd15

    wfd15 New Member

    I am aware that this post was from a year ago but I recently installed a 295HFS4 in my POV and ran into the same issue. Were you able to get an answer on how to wire up the slide switch in order to make it progressive? Thanks!
  3. TheHealer

    TheHealer Member


    When I didn't get any immediate replies on here (happens sometimes) I started researching any schematics I could find that related. I had the best luck looking at the schematics for a Federal Signal SW400SS switchbox, and found that the slide switch pretty much just operated using internal diodes.
    I ended up using a terminal block to accomplish what I needed. Output from position 1, 2, and 3 to their own spot on the block. On the input side of the block there are diodes that allow power into the block from each position wire, but not back to the control head, overkill I think as the slide switch moves from position to position but what the heck, lol. Additionally, on the block itself, there are diodes that control output power flow, so Switch Position 1 feeds Output 1 only, Switch Position 2 feeds Output 2 and can backfeed to #1 Output, and Switch Position 3 feeds Output 3 and backfeeds #2 output and thereby #1 output also, making it a progressive switch!

    Hopefully that makes sense, lemme know if a drawing would help!


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