Hey all im haveing problems with my 4wd i can hear the click when i go from 2wd to 4hi no click going from 4hi to hlo. and the light is flashing. i did some reading up on it lastnight. my question is where do i find the tccm fuse or do i disconnect the tccm

 

What you are driving would be helpful, but the tccm fuse is under the dash in the fuse panel.

 

sorry about that i have a 2000 s10 blazer LT

 

ok pulled 4wd fuse for 45 min now when i turn the key on all 4wd light come on going from 2wd to 4hi the light flashes going from 4hi to 4lo 4hi light stays on and 4lo flashes and going from 4lo to 4wd auto that light flashes. could the tccm be bad or the switch...im so frustrated and confused

 

The click or clunk you here when you select 4low may only be the trans going into low gear not 4wd, my 4x4 lights would flash when i had a leak in the vac line that runs to the 4wd actuator under the battery.

 

i hear the click from inside. i thought that was the tccm

 

ok so i checked things out found a broken vac line replaced it today and now i noticed that the front shaft is locked into 4wd but the switch is in 2wd any ideas

 

It sounds like the 4wd actuator on the top middle of the fire wall. Pull the line off it that runs under the battery, see if there is suction in 2wd, (there souldnt be) it should only allow vacuum in 4wd.

 

thank you i'll give a shot tomorrow

 

It actually sounds more like the transfer case motor is going but check for vacuum leaks with a vacuum tester. you can also put it in 4hi and get under the truck and see if you can rotate the front drive shaft in 4hi. That will tell you if its the transfer case or a vacuum leak. Read this link, it has all the info on reading TCCU codes on an odbII vehicle, https://blazerforum.com/forum/tech-a...ill-help-7180/