4 low switch stuck on

[feeny40]

1999 chevy blazer.Had the whole tranny replaced 10 months ago and now it started acting up. Took it back and they said everything is fine with the tranny and that my 4 low switch is on and telling my tranny to shift like it is on, but its not in 4 low.They said I have to take it to a dealer with a more high tech computer and they may be able to trip the switch back to off or tell what I need.I'm afraid of getting involved with the dealer, looking for a easy, cheap way around this.In the first 50 feet of take off its in overdrive, I can only bypass it by taking out the 4 wheel drive fuse out of the dash and then it shifts fine, but the gauges don't work in the dash ( gas) and such.

[Verto]

switch stuck mabye? try pulling the switch out, unplugging it and taking it apart, then clean the leads... put it back and try again... also try touching the plug wires together manually... if nothing works it may indeed be the 4WD computer

[feeny40]

I did take out the dash switch and tried that and everything seems good, the right lights light up and when I switch it there it does switch the case , but when its in 2wd and the 2wd light is on , it still shifts the tranny fast like its in 4 low, but its definatly not. thanks for your reply.

[Verto]

try unhooking the battery for like 15 mins to reset the comps? worth a try... but i dunno sounds like the comps are messing with eachother or something, like the 4WD comp is telling tranny comp the wrong info...

[muddog321]

What year cause different vac switches on them?
The xfer case encoder motor engages 4Lo - its only function so if thats engaging then you may be in 2 wd Lo - if the front axle coupler is not engaging also. More based on model year.

[feeny40]

Have tried the reset the comp. by disconneting the battery,even has been replaced since and the alternator also,someone said maybe my computer was getting irregular voltage.Still nothing, and it is not engaged in 4 low, have checked all that.The computer tells the tranny when to shift and its telling mine to shift really fast like its in 4 low.Is there a switch or senser i can unplug below, instead of taking out my 4 wd fuse and losing my gas gauge???????

[feeny40]

Sorry guys, its a 99 chevy blazer

[muddog321]

Sorry, I reread your post and the bottom line is its really in 4Lo or the trans shop is full of it. The trans when in 4Lo feels like it shifts faster but thats cause the ratio is twice as low. Its the trans solenoid classis 1-2 hard shift.
Take it back and make them fix it or tell them after the dealer fixes it they an refund the entire cost! What trans shop doesn't fix xfer cases! Keep on them.