I have a 1996 s-10 blazer that has the 3 button switch on the dash. When I hit the 4hi, I can hear the transfer case change over and the front drive shaft does lock it, but my front tires do not pull. I have changed the little actuarar (spelling sorry) I have also looked under the battery box and seen that the little vacum is not doing anything. What should I look for or what is that hooked up to?

Another problem I have is at the gas tank, when I toped off the tank the other day, it was leaking gas really bad, almost like just pouring it out on the ground. My gauge inside is not working right, when I hit my breaks it will go from 3/4 full to 1/4 and then back to 3/4 even when it only has 1/4 in it.

 

So what little actuator did you change then? The one under the battery?

If you are not getting vacuum to the actuator under the battery while in 4wd, then there could be one or more of the following wrong:

• Broken or restricted vacuum supply line to the vacuum switch on the transfer case
• Broken vacuum switch on the transfer case
• Broken or restricted vacuum line from the switch to the front axle actuator under the battery.

 

You definitely need to address the fuel leak issue... that could be very dangerous.
As far as the fuel gauge issue... You may need to just replace the entire fuel pump assembly which will include a new sender as part of the unit. This is a common problem with blazer fuel pump/sender units.

 

I changed the one on the front end. I have also checked the vacuum swithc on the transfer case. It is not doing anything. Should I replace it? If so where is a good place to get one, I tried advance auto and they said it was a dealer item only.

 

Sounds like you had a rookie parts guy helping you. Advance and Autozone carry the transfer case switch made by Dorman, in their "Help!" line.

https://www.dormanproducts.com/cgi-b...tegory_list=:0

http://www.autozone.com/autozone/cat...archText=49315


http://shop.advanceautoparts.com/web...WAMS_152849034___

 

Today I changed out the switch on the transfer case, and still nothing on the switch, now I have no idea what to look for to get the vacuum to work, any ideas?

 

This diagram should give you an idea of how things work under there:

 

But what do I need to check for the switch on the transfer case. I thought it would be the start of the vacuum, should it do something, I have replaced the lines and still nothing. The 4x4 does not work and I can not change my A/C from defrost to vents or to the floor.

 

is the vacuum line going to the vacuum ball connected ? sounds like you don't have any vacuum at all since those things are both driven by vacuum and if the line isn't connected to the ball then you might be out of luck, check the vacuum ball under the hood on the driver's side

 

Sounds like you may not even have the main vacuum supply line connected to the engine....