All 4 windows in my 99 400 are very slow, gets worse as the temperature drops. I've taken all 4 door skins off and greased the regulator tracks and "teeth" on that half gear. All window tracks in the door, (Felt lined), have been cleaned and lubricated. There has been no change to window performance. Are the window motors going out or is there another issue here? I've read that some have cleaned the electrical contacts in the switches and have had good luck with that. I haven't done that yet. Anyone that has fixed this issue please chime in for suggestions. Thanks.

 

Several things...

1.) Verify Alternator, battery, battery cables (especially negative). battery post terminals, engine and chassis ground cables and ground points are in good order. Measure voltage drop


2.) Did you remove and clean build-up from the window tracks? This cannot be done correctly without removing them first.. Which Toyota recommended lubricant did you apply?

3.) The window regulator must be removed to fully wipe clean and correctly lubricate friction points.
Lubricating the counter-spring is NOT recommended...however I used protectant FluidFilm.(on spring and metal parts only)

4.) The counter-spring may have diminshed tension after 20-30 years, so window up is bound to be slower than new.

5.) The window rollers may be gummed up and require cleaning and or replacement....subject to availability...

6.) Use Shin Etsu rubber grease on window rubber whetherstrip, but avoid application to any felt areas of weatherstrip or enjoy grease streaks on door glass for months to come.

7.) If original, replace all Littelfuse fuses.
sometime resistance builds up on contact blades after 20-30 years. See my post on topic

8.) Upgrade your alternator (100A) to 130A from a 2001-2003 LS430. Plug and play.... See my post on topic. Better under the curve power output for low RPM..

 

1. Alternator is charging good @ 14.2 volts. Both positive and negative terminals were replaced last year when the battery was. I will have to inspect the engine/chassis ground cables. I will measure the voltage drop of each window in both directions.
2. Did my best to clean the old grease residue with the tracks still in the door. The grease I applied was toyota body grease, (Yellow/cream color).
3. I will remove the regulator assemblies and clean them fully.
4. If required I will replace the regulators.
5. Regarding the rollers, I remember seeing a detailed write up on how to replace/clean them. If you have the link that would be great.
6. Yes I've been cleaning my windows, not going to make that mistake again of greasing those areas.
7. Will replace fuses.
8. Regarding the alternator, I will replace it with an LS430 unit if mine goes out.
I will report back with my results. Thank you for the detailed help.

 

See:

https://www.clublexus.com/forums/ls-...r-upgrade.html

https://www.clublexus.com/forums/ls-...-issues-2.html

https://www.clublexus.com/forums/ls-...brication.html

0

Product used on window regulator and return spring... Does an excellent job... Do not use on plastics or rubber.

https://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/808330-ls400-fuses.html

 

yodaone has very detailed threads on greasing the tracks among other things; see his links!