relaying a switched motor

Hi I'm busy rebuilding my father's car and the window winder cables and connectors are a bit old. They work fine but very very slow due to voltage drop. I have checked direct power to the motors and then they run like mad! Instead of redoing all the wiring and connectors - I tried cleaning contacts - doesn't work - I want to run power direct from the battery to the motor and have the original wiring just switch a relay. Sourcing new power to the start of the window winder switch is not going to work eithe as that switch is pretty old as well and gives a bit of voltage drop as well. Now.... The motor is not grounded. It has two wires coming from it. If you connect them 12v - Ground - they go up If you connect them Ground - 12v - they go down So. I can relay them but in my mind I only see a 6 relay option per door with a large amount of wiring. Is there a simple way of doing this? I understand relays but I can't wrap my head around this one to find a simple elegant solution. Your help in this is much appreciated. Thanks in advance.

It can be done with 2-SPDT Relays Option 1 Option 2

Perfect! Thank you so much!

You don't even need relays, a non-silicon spray in the channels plus new constant feeds, one per two windows, thicker gauge cables fused at 40 amps per two windows and run the grounds and power back to the battery.

i have bypassed the the 12v and ground coming in and the voltage drop through the switch is enough to slow it down quite a bit. The motor is extremely sensitive to voltage drop.

What vehicle?   BTW another method would be to wire in a 530t per pair of motors, you then get 1 touch on all the switches and the 530 does the trick (i.e. current switching).

This is al;l going round the houses, try a switch change first. But before doing that have you actually measured the switches internal resistance? Seems silly when it might just be corroded switch or fuse or connector contacts.

I am not 100% sure on this, but running a relay directly to the motor MAY bypass the resistance shutdown of the motor depending on where the actual shut down is located. If it is in the motor then you will be ok, but if it is built into the switch then you could have a problem. Basically if you ever happen to hold the button down for a little too long the motor will continue trying to open/close the window even though it is fully opened/closed. This will end up burning up the motor pretty quick.Kenny

Owner / Technician

KKD Garage LLC

Albany, NY 12205