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There is nothing quite like driving an older vehicle, regardless of who made it. It's like traveling back in time, a return to your youth. But there is something to be said about the modern vehicle, especially when the older iron starts to get frustrating to deal with on a daily basis. Things that were at first annoying to deal with, like daytime running lights, automatic door locking mechanisms, and other elements of a newer vehicle are now so commonplace that we tend to really miss their conveniences when driving an older vehicle that is fully manual.
One of those modern conveniences, and one that never occurred to anyone in the 1960s and 1970s, was multi-speed windshield wiper motors. In the last ten years, all vehicles now have multiple speed wipers, and they also have a delay setting that will pause the wipers at various intervals, which is handy with various levels of rain. When it’s raining mildly, it’s inconvenient and annoying to have the wipers keep running with no delay, so modern wiper motors have a delay function that can send them wiping every 1–10 seconds or so, fully adjustable by the driver, so that you don’t have to constantly turn the wipers on and off as you’re driving.
True to form, Detroit Speed has all kinds of kits and parts to bring modern OE engineering to older vehicles, and their Selecta-Speed wiper controls are one of them. Coming from a career as a General Motors engineer, Detroit Speed’s founder and president Kyle Tucker has dedicated his company to just that: melding modern OE engineering principles to older cars though his company. The Selecta-Speed system is one of those modern convenience items for older cars that got our attention years ago. Not only is it convenient, but it uses a modern, compact wiper motor that allows more room for things like brake boosters and such and really cleans up the firewall, lending a modern Pro Touring vibe to the vehicle.
We wanted to see just how easy it is to install a Selecta-Speed system on a vehicle and chose the ever-popular "Squarebody" GM truck, since that is such a hot property in today’s world. The Squarebodies are approaching and sometimes eclipsing the value of earlier GM C10 trucks, so our choice was a good one. And as we found out, installation is shockingly simple, requiring basic hand tools and about an hour or so of garage time.
The Selecta-Speed kit has a 7-speed wiper system with five delays and the kit features a washer pump control on the switch that has a push button function. A wiring harness and control module are included in the kit, and the washer pump is an optional part (Part no. 121102) that is easy to install. There simply is no reason for not adding it if you are going to all of this trouble.
Let’s look at the installation process as it happened on our Squarebody, and know that Detroit Speed has kits for pretty much every other domestic vehicle built before 1980, and the installation is more or less the same.
Here’s the DS Selecta-Speed kit and washer pump (middle bottom) an all the tools needed for installation. As you can see, they are just basic hand tools and a wire cutter/crimper for a few small wiring changes.
This is the 1983 Chevrolet C10 we used for this installation. It was 100% stock with little road rash or abuse, which will make for a nice solid canvas with which to build a killer hot rod.
The stock wiper motor for our C10 does work, but it is a basic two-speed unit...and is plenty ugly to boot.
Detroit Speed uses a modern motor that is much more compact to clear items like brake boosters, plumbing and other things that might get in the way. This new motor offers all the modern conveniences that come with a new car, unlike the old motor that has only came with two speeds (three if you count “off”).
This is the Wiper Control Module that, as the name implies, controls the wipers, bringing all of their functions into place. It mounts under the dash, which we’ll outline later.
Before removing the stock wiper motor, make sure the wipers are “parked” at their off position and disconnect the negative battery cable to eliminate all power to the truck. It might help to mark the wiper position with a piece of masking tape before removing the stock motor since you’ll need to manually move the wipers to make it easier to access the linkage when removing the motor. You’ll need the wipers at about their mid-point of their travel to allow access to the mount. Then unbolt the stock motor and install the new motor. The original wiring will not be used with the Selecta-Speed Wiper kit; a custom harness is provided to replace the original harness. If you decide to cut the old wires to clean up the firewall, terminate the wire ends to avoid any shorting. The new motor has an attached adapter plate that mounts to the original firewall weld nuts with three supplied 10-24x3/4 button-head screws.
Here's a better shot of the Selecta-Speed wiper motor mounted.
To access the wiper switch, remove the stock dash bezel. Depending on the vehicle, it might be easier to remove the knob from the wiper switch first. Pull the switch out as far as you can and press down on the release button (yellow arrow) to pull the knob and shaft out.
We didn’t have to remove the knob on our truck, but this is what the switch looks like with the washer switch just above it. The washer switch will be replaced with a new LED and clear plastic panel when it all goes back together.
Remove the two screws holding the stock wiper switch to the dash and disconnect the connector from the back of the switch. Once the switch is removed, then remove the light bulb housing by turning it counter-clockwise in the switch housing.
Once the wiper switch is removed from the dash, cut the “A” an “E” wires from the back of the original wiper switch connector in order to use the LED bulb. The “A” wire is gray (positive) and the “E” wire is black (ground). Cut them as close to the terminals as possible.
Strip the wires that were cut for the light bulb, the wires on the provided dimmer, and LED wires for the provide two-wire T-junction connecter. Use the indicator on the bottom of the T-junction connector to unsure that enough wire is stripped.
Remove the nut provided on the LED and insert the LED through the square hole in the front for the wiper switch light box assembly, then install the nut back onto the LED and tighten it with an 8mm wrench. The install the wiper switch through the back of the light box assembly, making sure the anti-rotation tab on the switch locks into the anti-rotation hole in the light box assembly.
Use the provided two-wire T-junction connector to safely connect the LED dimmer to the original wires from the wiper switch bulb. Ensure that you are connecting the “5-24V” side of the dimmer to the original truck wires. This is indicated on the label of the dimmer. Using one of the connectors, feed the gray wire from the original harness into one hole and the red wire from the dimmer into the other hole until they bottom out. Using a second connector, feed the black wire from the harness into one hole and the black wire from the dimmer into the other hole until they bottom out, then close the orange levers to lock them in place. Gently pull on them to ensure that the wires are fully locked in place. You can also solder and heat-shrink the wires together if you’re not a fan of these types of connectors. Once those wires are connected, install another set of T-junction connecters onto the other end of the LED dimmer.
Ensure that you’re connecting the LED side of the dimmer to the original wires. This is indicated on the label of the dimmer. Insert the LED wires to the LED dimmer connectors paying close attention to the wire colors. The black wire on the LED should connect to the black wire on the dimmer and the red wire goes to the red wire. Wiring them backwards won’t hurt anything but they won’t work properly. Before the gauge panel is re-installed, you’ll need to set the LED brightness on the dimmer to match your other gauges. Do it in a dark garage if you can after reconnecting the battery for a minute.
Place the provided acrylic wiper cover plate over the light box assembly and turn on the headlights. If the wiper LED doesn’t illuminate, hold the middle “Speed/0/Power” button until the LED turns on. Then press the “light/star” button to activate the static mode. In this mode, the middle button will make the bulb dimmer, and the “light/start” button will make it brighter. There are 10 different brightness settings. If the LED doesn’t turn on or respond to button presses, you probably have one of the connectors wired backwards. Double-check that. Once the brightness is set, tuck the wiring behind the dash with the switch wiring, Then, remember to disconnect the battery cable again.
Re-install the gauge panel to the dash using the original fasteners and slide the wiper knob onto the shaft of the switch.
Route the wiper motor connector side of the harness through the firewall, which in this case required a new hole to be drilled to make room for the connector--we used a 1-1/4” Unibit. Some 1975-1983 trucks have a grommet already in place that can be used.
Once you pulled enough of the harness through the firewall, connect the wiper motor connector to it as shown. Not shown in this photo is the grommet we used to fill in the remainder of the hole we drilled for the harness.
If you are using the washer pump kit (and you should be!), use the instructions that came with it and find the best place to mount the washer motor. We just installed it on the top of the inner fender panel but are considering a cleaner, less obvious place to mount it. It uses the stock rubber washer hoses with a little plastic T connector.
Now’s the time to install the wiper control module under the dash. You can install it anywhere as Detroit Speed provides you with a bolt, Nylock nut and washer, but we found a spot on the kick panel above the hood release that makes it easier (though you have to be a bit of a contortionist to reach it). With the module in place, plug in the wiper switch and harness connectors into it. Then connect the yellow wire under the dash to a 12V ignition or accessory switched source and the black wire to a ground. And you’re done! Enjoy your modern multi-speed wipers!
