rollingcoal1989

Hey guys sold my 96 cummins just picked up a 99 cummins ext cab silver and the 5.9 was board and sleeved to a 6.1 and has a ats tranny and other upgrades so my brake light stays on sometimes will go oit for a few seconds but comes right back on any ideas

dieseldemon

Check switch under dash on brake pedal

patdaly

Yep, pull Ebrake release handle and pull back on the Ebrake lever at the same time, does light go out?

rollingcoal1989

No tried pulling e brake release and pull up on pedal and still nothing comes on omce I get a liitle speed goin and evey once in a while will go out but comes bavk on usallystays on tho

VADSLRAM

On the '99 it is a strange multi contact switch that is really a pain to put back on right if it gets removed. It has seperate contacts for the ABS circuit, the brake lights and another set that I have no clue what it does.
It has a "self adjuster" that works once. You install the switch with a travel lock on it then with the brake pedal in place and the switch secured you pull the lock. It lets the plunger snap out to the correct lentgh but after the first
snap it won't go re adjust. If you are under the dash and are leaning on the brake pedal with your head then reach up and grab the brake pedal at the switch to adjust your position you just might hear a little ratcheting zipper like sound...then your ABS light will stay on, then you might try to adjust it manually and your ABS ligh will stay on AND your brake lights won't work.
Yes I am saying this from personal experience. Lucky though that the switch itself is cheap.