While installing a new battery in my Blazer, I found this hose with a cap on the end wedged in between my old battery and coolant tank. The hose seems to lead to the back of the engine near the rear of the intake manifold. Im thinking its some sort of vent but If that's the case, why is it sitting all the way up front next to the battery?

 

its hard to tell from the pic but it may be the front diff vent

 

Isn't there a vent that goes to the t-case, that's part of the front axle actuator system? I saw one similar on mine when I pulled out my vacuum actuator. I didn't really pay it much attention, as I was putting in a posi lock setup.

Could also be the vent for the front diff, as well.

 

Thanks a lot guys. I've had 3 of these blazers (all 4x4) and my dad has one as well but we've never seen that before, lol.

 

get another picture from a little further away....that might help some other people on here.

 

That could be the Intake hose for the Secondary Air Injection Pump. Pump is usually located below the radiator on passenger side. Its intake hose needs top be high enough so no water gets in during driving and operation. The cap is probably open around its outer diameter and is designed so water won't splash in.

Looks too big for a TC or Diff vent.

 

Thanks a lot guys, Ill look harder and see where it goes exactly. As for taking a picture farther away, thats only going to show more of the engine bay and not where the line goes since the line goes straight down.