2nd Gen Non-Engine/Transmission "1999" 2500 Heating/Cooler fan intermittent (Strange)

[REdmon]

I have a 1999 2500 that has just started experiencing problems when I turn on the AC (turned to high). I can hear the motor turning, but nothing is coming out the vents. If I turn the switch back off and then turn it to low, the fan will blow cold air out and I can progressively increase the fan spped (fan slipping on the shaft???). With the AC blowing, if I pull up to a stop sign, the air stops coming out of the vents, and once I drive off, the air start blowing from the vents again.



I believe I read out here before that if a fan is slipping, you have to pull the whole dash out to make a replacement (I searched the forum but can't seem to locate that thread). If anyone is familiar with the problem I am having, I would appreciate your help on how to proceed. Also, do you really need to pull the dash to make a blower motor replacemnt?



Thanks,



Ron

 

[B.G. Smith]

Before you go too far with the trouble shooting, check and make sure you have good vacuum. I think when you loose vacuum the system defaults to defrost? bg

 

[Ram4Sam]

I have a 1999 2500 that has just started experiencing problems when I turn on the AC (turned to high). I can hear the motor turning, but nothing is coming out the vents. If I turn the switch back off and then turn it to low, the fan will blow cold air out and I can progressively increase the fan spped (fan slipping on the shaft???). With the AC blowing, if I pull up to a stop sign, the air stops coming out of the vents, and once I drive off, the air start blowing from the vents again.



I believe I read out here before that if a fan is slipping, you have to pull the whole dash out to make a replacement (I searched the forum but can't seem to locate that thread). If anyone is familiar with the problem I am having, I would appreciate your help on how to proceed. Also, do you really need to pull the dash to make a blower motor replacemnt?



Thanks,



Ron

Look for a small vacuum leak... ... the hvac system defaults to defrost with no vacuum. At idle, vac pump not running fast and not enough vacuum, hence default to defrost. Since it starts blowing out the ac vents when you take off, the vac pump spins faster, more vacuum, more air cond. Check the line from the vac pump up to the firewall(under the rear hood gasket). There is a tee fitting under there with several connections, mine has split a hose there twice over the years.



Sam

 

[GAmes]

Just an FYI. Removing the fan and motor is easy. Three 8mm bolts hold it in. It is under the HVAC, below the glove box.

 

[REdmon]

I have found the leak in the hose, but I am unsure what I need to order to make the replacement. Temporary, I have covered up the torn hose with silicon tape and reinforced with electrical tape. That has the air blowing out the vents correctly. Anyone know the exact part number I need to order? Hole is located just above the white spot of the flashlight.

Thanks,



Ron

 

[B.G. Smith]

If it the small hose I am seeing don't bother with Genos unless you are in the wilderness somewhere. Cut off a short piece and take it to your nearest auto parts store and buy enough hose to reolace all of it. If it goes into truck before you see a connection, buy a splice for that size hose and terminate the new hase as near the cab as you can. bg