Power window problem

Maybe someone can help. I am getting 11.5 volts to the RH window motor but only get 8.5-9 when the switch is activated. Window goes up very slow, sometimes not making it up all the way. Any ideas.

High resistance in the circut, every connector & switch contact adds to the problem, master switch & seperate door switch are both actice parts of the circut....Thats why I reworked my power windows & I've helped a few friends do the same....I wrote it out awhile back so this is a cut & paste..


I used a toal of eight standard format Bosch 30 amp relay & connectors avalible at any car stereo/alarm shop, I used a 12ga fusible link connected to a 8 gauge wire from the + post on the starter (trying to keep the modification invisable) from there I passed through an unused firewall plug, under the dash I split the power off into four 10ga leads they are crimped & soldered, then I routed them to each window cavity, these leads will now be the power to run the windows, at the window cavity they split again but remain 10ga wires providing 12v to pin 87 on two Bosch relays..Connect pins 85 & 87a to a good ground...Connect the original switch leads one to each relay to pin 86 & connect pin 30 to the motor leads...Now the switches only carry less than .3 amp whereas before they carried 6+ amps...Originally that load passed through the bulkhead connector half a dozen connectors & the switches, every one causing a voltage drop, now you get a full 12v with good amperage avalible, the motors may have been damaged by running on reduced current before, usually they are fine, the conversion takes a little effort but the results are worth it..

Always a bit dodgy to diagnose a problem from a distance, but here goes (chuckle);

My guess would be the motor is drawing a lot of current when it is turned on and that is causing the voltage drop. The reason for the excess current draw could be a mechanical bind.

So, to pinpoint my guess, I would suspect the tracks, rollers and regulator mechnism are all dirty and full of 40 year old (hard as a rock) grease. Try taking the stuff aparts, cleaning everything and replacing the rollers and regreasing all the bits - betcha it starts working really well!

Hope that helps!

John P.