4x4 vacuum 1994 blazer s-10

[ken taylor]

the three vacuum lines that are on the switch on tranfer case ,1 to the
intake .
1 to the vacuum for front axle .
the third goes to ?

[Mikado14]

The third is a vent. When you disengage the 4WD, the vacuum that is applied to the actuator has to be vented to the atmosphere. You should be able to find the vent on the firewall. It will be a vacuum hose with a vent cap in the end. Mostly in the vicinity of the heater box towards the center of firewall.

[ken taylor]

thanks for help , so 1of the 3 vacuum ports on the vacuum switch is a vent ,is the cap a check valve??

[Mikado14]

No, it is not a check valve on any that I have worked on. Just a vent plug in the end of the hose.

[s10blazerman4x4]

would these vacuum hoses solve a grinding noise going from 4 high to 4 low in neutral
91 s10 blazer 4.3
what about the light bulb behind there what is needed to replace that
any help would be great thanks

[Mikado14]

First, I will assume that you are talking about a manual floor shifter for the 4X4. You will need to unscrew the cover to get to the bulb. I always thought it was a little PITA but it's worth it.

As far as the grinding goes, no, the vacuum lines only control the front axle. Assuming of course, that the grinding is coming from the transfer case.

[s10blazerman4x4]

yeh thats where it sounds like its comin from i only asked because mine only engages half of the time so i didnt know if it was the hoses mine goes in for inspection next month ill have him check it out i asked bout the light bulb because my uncle had asked me if i knew how to go bout it cuz is went out is that a courtesy bulb or just somethin you would take out and goto the store and have them find

[ken taylor]

thanks found that line cap was missing. exhaust burnt it into.
some one had hooked the vent line into the line that goes to actuator
thanks alot. think that was the fix.