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dc motor with limit switches wireing help Answered

I have a 1998 Trans am that has power windows. The problem is the doors are fiber glass and the motors create a lot of force on the doors creating problems. What I want to do is put a limit switch at the top and bottom of the window travel.        I'm using the factory switch that sends +12 volts in the up or down direction   I have a dc motor, limit switches and dpdt relays. I need to know how to wire it all together. If you could draw a picture that shows all wires from switch to relays to micro switches to motor that would be best. Thank you for your help     E mail dmarker5@hotmail.com


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4 years ago

I realize that I'm replying to a very old request for information...

Which was made two years ago regarding adding limit
switches to protect the mechanicals of a D.C. motor operated mover, from over
travel. i.e.. (1998 Trans am that has power windows. The problem is the doors
are fiber glass and the motors create a lot of force on the doors creating
problems. )

The circuit you describe is already in wide-spread use across the elevator
industry as a safety to control the travel limits of elevator
Essentially it's a basic electrical logic circuit to avert catastrophic
failure caused by over-travel.

It has many uses...

Check out the GIF diagram at the following link, I believe it will answer
your original question.

Please disregard if you no longer find this information of


6 years ago

Normally closed limit switches on both ends, common ground for the motor and the switches in the positive lead, no picture needed ;)

When the window hits the top the switch opens the connection, same for the bottom, as the other direction in unaffected it simply works ;)


Reply 6 years ago

Here is a picture of my project. the motor has only two wires so the polarity is switched for up and down I need help on wiring the switch to the relays to the switches to the motor. if someone could draw the wires in that would be vary helpful I know nothing about relays and how they work. Thanks for your help. (THE POWER COMING IN FROM THE SWITCH WILL CHANGE FROM POS. TO NEG. DEPENDING ON THE DIRECTION YOU PUSH THE SWITCH)


Reply 6 years ago

That system indeed makes it quite hard to modify as you would need electronics to "read" the switches and with a two wire system it get's complicated quite quick.

I had a look at my doors as the car had electric windows fitted by came without them from the factory.

Switches and so are all genuine but the actual window winder system is aftermarket.

On the control units is a limit switch, not for the position but for the maximum foce the motor will apply to the window.

So I can simply turn a potentiometer to get just enough power to get the window up completely.

Can't make out how the input and output of your switches is related but if one side of the three terminals is for up and the other for down it should be possible to wire the switches in between.

For example first 3-block is up, a ormally closed switch on the output line to the motor will stop it when hit.

Same for the other side.

If you have any spare 12V motor or cordless drill you can hook it up to your switches and gice it a test.