Air Flow is very weak on my 1998 K2500

[Braydenw958]

I think I found the problem hahaha I clean it up and let y’all know if it fixes the problem

You must be registered for see images attach

 

[someotherguy]

The main issue is typically a debris-plugged evaporator core. Pine needles, leaves, cottonwood fluff, butterflies...anything that falls into the HVAC plenum can be pulled down into the blower motor fan area, and then plastered against the Evaporator.

NOT the worst I've seen...but the only one I have photos of.

You must be registered for see images attach

This picture is actually very useful - it shows the a/c box IN PLACE on the truck, but with the blower housing removed, no need to evacuate the a/c to get the blower housing off and do a more thorough cleaning than you can with it in place. Is this pic one of yours or did you find it on the net? I was just talking about the possibility of such an approach in a different thread, early this morning, thinking from appearances it looked like it was possible. This pic pretty much proves it. I'll still say at least the top rearmost screw is difficult to handle, but clearly not impossible.

Richard

 

[Schurkey]

That photo is of my '88 K1500, during my month-long crusade to fix "no heat" in the cab. This is when I got my "learning experience" in the '88 service manual being LOADED with errors--so many that they had to publish a "Service Manual Suppliment" to correct most of 'em. Among the errors was the procedure for removing the dash, which was needed to get the heater box out.

You must be registered for see images attach

I'd drive 35 miles one-way, nearly-all highway miles to get to work, and I had to wear a snowmobile suit because the cab was FREEZING COLD in the winter.

I actually had the heater core replaced because I though the heater was the problem. Nope. The actual problem was a failed foam gasket at the top of the blower housing, where it connects to the stamped-sheetmetal of the plenum. There was such a humongous cold-air leak that the heater couldn't keep up.

Sealed the plastic blower-box to the underside of the plenum with hardware-store adhesive-backed foam tape, and now the heater will roast me out of the cab at -20F ambient temp.

 

[someotherguy]

That photo is of my '88 K1500, during my month-long crusade to fix "no heat" in the cab. This is when I got my "learning experience" in the '88 service manual being LOADED with errors--so many that they had to publish a "Service Manual Suppliment" to correct most of 'em. Among the errors was the procedure for removing the dash, which was needed to get the heater box out.

You must be registered for see images attach

I'd drive 35 miles one-way, nearly-all highway miles to get to work, and I had to wear a snowmobile suit because the cab was FREEZING COLD in the winter.

I actually had the heater core replaced because I though the heater was the problem. Nope. The actual problem was a failed foam gasket at the top of the blower housing, where it connects to the stamped-sheetmetal of the plenum. There was such a humongous cold-air leak that the heater couldn't keep up.

Sealed the plastic blower-box to the underside of the plenum with hardware-store adhesive-backed foam tape, and now the heater will roast me out of the cab at -20F ambient temp.

When I lived in ATL, which doesn't get cold by your standards, but cold enough in the winter to bother me - I would always feel freezing cold air blowing in on the floor of my '92 C1500 ECLB. That was the truck that later I would discover had been wrecked on the passenger side badly enough to dent the firewall, which broke the a/c box, right at the fresh air inlet and recirculate door.. so it was always letting in outside air, and blowing it directly towards the floor under the blower housing.

You must be registered for see images attach

Some fine sledgehammer work on the firewall, and a replacement box, got everything sorted out.

Richard

 

[Beast99]

Try swapping the wires connected to the blower. Mine were reversed and it barely whispered to me. Also, don’t worry about the rubber cover. It’ll knock the cooling hose out of the blower.

 

[edon]

To OP, when you checked your actuator motors and flaps, did the air flow fully switch to the selected position? My ‘98 has the problem where all the rubber surrounding the flaps has broken off so none of the flaps seal anymore. Air just goes everywhere all the time.