Lotus Esprit Power Window Boosters





Tired of slow or non functional power windows in your Esprit? These window boost effectively turbocharge your window motors. Unfortuantely part of add lightness meant, no power window relays. All the electric load goes through the switches and as they wear out the windows get slower and slower.


When you push one of your electric window switch(es) all the power from the car battery goes thru the electric window switch and then on to the electric window motor(s).  Any degradation of the contacts in the electric window switch(es) results in the electric window motors receiving less than 100% of the battery power.  As the electric window switches in your Esprit age they wear and lose their ability to pass power on to the electric window motors.  Once these Electric Window Helper Modules are installed, all the power sent to the electric window motor is now sent thru these units.  Your electric window switches now control the window accelerator units.  Even the most worn and degraded electric window switches will still work and control these units. Also because these units ground to the door, so the current does not have to pass all the way through the body wiring to another ground location.


These install in each door. Installation takes under 30 minutes each. 


Typical install:


Window Booster wire colors and 1990 SE wire colors

Red - power (I used the original power wire going to the window switch inside the door) - yellow/green - use the larger crimp for this. Cut the original wire, strip it, place the crimp on one end. Place the other wire AND the red wire into the open end of the crimp. Don't forget to slide the heat shrink on there first. 

Black - ground, attach to one of the 6mm studs above the power window motor

Blue (either one) - cut one power window motor wire, connect the motor side of cut wire to green/yellow

Blue (other one) - cut the other power window wire and atach this wire to the motor side

White (either one) - attach to switch side of the wire you just cut.

White (other one) - attach to the switch side of the wire you just cut


TEST before reassembly. If the window moves the opposite direction then you can either rotate the switch in the bezel, or swap either the blue wires or the white wires (not both)


Don't forget to check the track alignment and grease them while you have the door panel off.


If you want the windows even faster you can run a dedicated FUSED power wire from the battery, fuse box, or accessory post in the front trunk to each booster. 


These are sold in pairs, so quantity one is enough to do one Esprit.









1990 Esprit SE specific instructions:


ATS Power Window Booster instructions.
I got another 1990 SE and the power windows were not working. I was going to make a quick before video but the window stuck in the down position. So a static photo would show the same as the video. Haha.
The ATS window boosters basically add a much needed smart relay setup to the window electronics. They reduce the electrical load in the switches to almost nothing. They also add a ground very near the motor so current doesn’t have to travel back down the harness.
Installation is pretty easy. Takes about half an hour and is done entirely inside the door.
I’m going to update the packaging on our website so it comes with crimps, heat shrink, etc.
GET SOME REAL CRIMPERS like shown in the last photo.
Cut one of the power window motor wires. I do this pretty close to the motor. In fact I eliminated the factory butt connectors. Less
Connectors, less resistance. Let’s start with the grey wire with green stripe. Cut it. Attach the either of the blue booster wires to the motor side. Connect the one of the white booster wires to the switch side of the wire you just cut.
Repeat for the second motor wire. Mine was grey with a pink or brown stripe. The other white goes towards the switch. The other blue goes towards the motor.
Next you are going to T into the fattest power wire going to the power window switch. On my 1990 car it was yellow with a green stripe. Connect the red wire here.
After that connect the ground wire to the factory ground position above the motor.
Finally zip tie the booster out of the way so it won’t get touched by the window regulator.
Reinstall the door panel and test. If the window moves the wrong direction you can either rotate the switch, or you can swap either the white wires or the blue wires, but not both.
Edit - I am assembling the little install hardware kits. You'll get three larger crimps. You need two and I include an extra. These are for the main power wire, aka the red wire on the boost. It Tees into the yellow/green wire (on a 1990 SE) power wires.
You'll also get 9 small crimps, you need eight.
Two small zip ties for wire management
Two large zip ties for securing the booster inside the door.


Price: $129.00

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