I have a 1999 Sport with the 4.0 and five speed. Once I drive it and it warms up there is always hot air coming from the floor vent. Doesn't matter if the fan is on or off. I also have AC. Is this a common thing or do I have a problem I'm unaware of????
Heat Always Coming Out Of Floor Vent
- Thread starter MK212MX
- Start date
Sure it's blowing from the floor vent and not just heat from below radiating up?
Entirely possible your HVAC box and doors are all gummed up with twenty plus years of crap.
You could try opening the cowl and vacuuming out what you can
...or using compressed air...
Might need to pull the HVAC box ...
-Mac
Entirely possible your HVAC box and doors are all gummed up with twenty plus years of crap.
You could try opening the cowl and vacuuming out what you can
...or using compressed air...
Might need to pull the HVAC box ...
-Mac
Definitely coming from the floor vent. Never messed with the HVAC box, Jeep only has 37K miles. I will check into it and give that a shot. Thanks!
Since it occurs when the vehicle is moving and not when stationary; the problem is probably vacuum related.
There is supposed to be a check valve in the vacuum line where the A/C refrigerant lines go thru the firewall. The check will close off the vacuum in the lines going to the A/C climate control damper actuators.
You will need to start tracing out the vacuum line looking for loose fittings or cracks in the vacuum lines.
The picture below will assist you in tracing out the vacuum lines.
There is supposed to be a check valve in the vacuum line where the A/C refrigerant lines go thru the firewall. The check will close off the vacuum in the lines going to the A/C climate control damper actuators.
You will need to start tracing out the vacuum line looking for loose fittings or cracks in the vacuum lines.
The picture below will assist you in tracing out the vacuum lines.
If you find your problem, post some pics of the vacuum leak. This is a common problem, and others often wonder where to check for most likely locations of a leak.
Since it only happens when moving, I suggest starting with the simple stuff and making sure that you have no open holes in the firewall, toe board or tunnel. A seemingly small missing boot/grommet can let in a lot of engine bay heat.
This. Check your inner shift boot....it's probably shot
Mine is gone and whenever I roll my windows down, it blasts out unbelievably hot on my legs, coming out from right beside the vent. It's all the hot air coming from the transmission tunnel into the cabin
Ok report back. Shift boot good, all vacuum line in tact and look solid. I did find this and repositioned correctly the boot after adding some fresh grease to the shaft. This should help. I have not driven it to see if that was the total issue.
Then I noticed this connector which someone disconnected and tied down with electrical tape under the heater box. Anyone know what this is for???
Then I noticed this connector which someone disconnected and tied down with electrical tape under the heater box. Anyone know what this is for???
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It's to supply power to the bulb for the lighted shift indicator bezel in the automatic transmission. You have a manual, so it does nothing and goes nowhere for you.
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