Here's an annoying one... On my 99 Wrangler Sport...

I have hardly any air running up to the defroster. It's blowing, just
something in the vent system doesn't seem to be opening up.

Other times I'll be driving along with the heater or AC on and it'll
make a 'thunking' noise like something is opening or closing.. and the
fan will shut off.

I've surmissed it must be vacuum related.. but anyone know how/where to
check this?

Joseph

 

The main vacuum connection should be on the rear corner of the intake
manifold. I would start there looking for a cracked fitting or line.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Aug./05 http://www.imagestation.com/album/in...?id=2120343242
(More Off Road album links at bottom of the view page)

Ice wrote:
>
> Here's an annoying one... On my 99 Wrangler Sport...
>
> I have hardly any air running up to the defroster. It's blowing, just
> something in the vent system doesn't seem to be opening up.
>
> Other times I'll be driving along with the heater or AC on and it'll
> make a 'thunking' noise like something is opening or closing.. and the
> fan will shut off.
>
> I've surmissed it must be vacuum related.. but anyone know how/where to
> check this?
>
> Joseph

 

The main vacuum connection should be on the rear corner of the intake
manifold. I would start there looking for a cracked fitting or line.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Aug./05 http://www.imagestation.com/album/in...?id=2120343242
(More Off Road album links at bottom of the view page)

Ice wrote:
>
> Here's an annoying one... On my 99 Wrangler Sport...
>
> I have hardly any air running up to the defroster. It's blowing, just
> something in the vent system doesn't seem to be opening up.
>
> Other times I'll be driving along with the heater or AC on and it'll
> make a 'thunking' noise like something is opening or closing.. and the
> fan will shut off.
>
> I've surmissed it must be vacuum related.. but anyone know how/where to
> check this?
>
> Joseph

 

The main vacuum connection should be on the rear corner of the intake
manifold. I would start there looking for a cracked fitting or line.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Aug./05 http://www.imagestation.com/album/in...?id=2120343242
(More Off Road album links at bottom of the view page)

Ice wrote:
>
> Here's an annoying one... On my 99 Wrangler Sport...
>
> I have hardly any air running up to the defroster. It's blowing, just
> something in the vent system doesn't seem to be opening up.
>
> Other times I'll be driving along with the heater or AC on and it'll
> make a 'thunking' noise like something is opening or closing.. and the
> fan will shut off.
>
> I've surmissed it must be vacuum related.. but anyone know how/where to
> check this?
>
> Joseph

 

Real Jeeps don't have vacuum control on the heater.

Earle

"Ice" <joseph@vndinc.com> wrote in message
news:1134842393.197495.327100@f14g2000cwb.googlegr oups.com...
> Here's an annoying one... On my 99 Wrangler Sport...
>
> I have hardly any air running up to the defroster. It's blowing, just
> something in the vent system doesn't seem to be opening up.
>
> Other times I'll be driving along with the heater or AC on and it'll
> make a 'thunking' noise like something is opening or closing.. and the
> fan will shut off.
>
> I've surmissed it must be vacuum related.. but anyone know how/where to
> check this?
>
> Joseph
>

 

Real Jeeps don't have vacuum control on the heater.

Earle

"Ice" <joseph@vndinc.com> wrote in message
news:1134842393.197495.327100@f14g2000cwb.googlegr oups.com...
> Here's an annoying one... On my 99 Wrangler Sport...
>
> I have hardly any air running up to the defroster. It's blowing, just
> something in the vent system doesn't seem to be opening up.
>
> Other times I'll be driving along with the heater or AC on and it'll
> make a 'thunking' noise like something is opening or closing.. and the
> fan will shut off.
>
> I've surmissed it must be vacuum related.. but anyone know how/where to
> check this?
>
> Joseph
>

 

Real Jeeps don't have vacuum control on the heater.

Earle

"Ice" <joseph@vndinc.com> wrote in message
news:1134842393.197495.327100@f14g2000cwb.googlegr oups.com...
> Here's an annoying one... On my 99 Wrangler Sport...
>
> I have hardly any air running up to the defroster. It's blowing, just
> something in the vent system doesn't seem to be opening up.
>
> Other times I'll be driving along with the heater or AC on and it'll
> make a 'thunking' noise like something is opening or closing.. and the
> fan will shut off.
>
> I've surmissed it must be vacuum related.. but anyone know how/where to
> check this?
>
> Joseph
>

 

Most "real" Jeeps don't even have working heaters until you get moving
;-)

 

Most "real" Jeeps don't even have working heaters until you get moving
;-)

 

Most "real" Jeeps don't even have working heaters until you get moving
;-)