Tailgate Window Circuit Modifications
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'92-96 shown; '87-91 similar; NONE OF THESE control switch improvements (left 2 columns) will work for '78-86 Broncos due to the internal wiring of the dash switch. The simplifications, indicator lamp, & 1-touch WILL work on '78-96.



The factory circuit passes full current through 4 terminals of BOTH switches every time the window is used, resulting in high resistance & slow window movement. The modified circuits:
- reduce the current passing through the switches (making them last longer);
- replace the special switches with 2 common relays (making them easier to replace if they ever go bad);
- allows any number of additional switches with no degredation in performance;
- uses the factory wiring & circuit breakers, and requires NO new wires through the tailgate hinge (for most trucks). If the truck doesn't have a factory defrost ground wire, then one heavy ground must be added from the body inside the L taillight well to the tailgate relays & switch.

The Improved (Ground-Switched) Circuit has the benefits of converting to always-on, and having no hot wires strung through the truck. This is the best way to add switches &/or improve t/g window function. Note that there are no modifications to the frame harness.

The Hot-Switched circuit has the benefit of being simpler to rewire. But the grounds MUST be removed from the dash switch connector, and a fused hot wire must be strung to each new switch location.

The Loaded Circuit adds 1-touch modules & an indicator light to the ground-switched circuit, but both of those mods will work equally well on the hot-switched circuit, or the stock circuit.



The Simplified circuits reduce the motor to a single control switch, but do NOT protect the window from accidental breakage by raising the t/g after raising the glass.

The indicator lamp is not required in the One-Touch circuit, but it's a simple & useful addition to ANY circuit with a functional latch safety switch, including those where the indicator lamp is not shown. An easy lamp to use is RadioShack 272-0332. Any lamp used in this application must light in either polarity, like an incandescent bulb or a double-polarity LED.



Making the dash switch (& door windows) work at all times is another HIGHLY-functional mod.



But if the 1-touch modules catch rain with the always-on mod, they will short; lowering the windows &/or draining the battery.

See also:

Owner caption November 2025 · Photo 0 of 5000