how to fix 1994 gmc sierra heater to blow out hot air

shana18969
0

Asked by shana18969 Feb 01, 2013 at 06:24 PM about the 1994 GMC Sierra 1500 K1500 SL 4WD Standard Cab LB

Question type: Maintenance & Repair

put new thermostat and the heater is not working

8 Answers

DavidH25
Not Active

Assuming the radiator is topped off, the most likely your heater core is not getting hot water to it. The valve that controls the flow may be stuck, or the linkage to it. Locate that valve, inline on heater hoses and try opening it by hand. Let's start there

4 out of 4 people think this is helpful.
judge_roy
Not Active

You must FLUSH the heatercore now. takes an odd combination of a pressure fitting on a hose fitting to flush 'er clean. Problem is getting the air out of the system. once a heatercore becomes air-bound, it is pratically impossible for it to see the light of day. We've joked amongst our fellow mechanicsm "just park it on a hill" which has a strange wisdom to it....continuing problem for heater core service-....in short flush the core with water, blast the core with air...and say a little prayer :)

1 out of 1 people think this is helpful.
Chris Austin
535

did you flush out heater core?, check to make sure there is no line blockage, and change coolant, chances r its green so its fairly cheap to do this, at the shop i work at its 70 $ plus tax for green coolant flush, fully drain and hose out rad and lines as best you can and refill with 1 jug of pure green coolant and then fill with 1 jug of water, top off with 50/50 mix of coolant and water, preferably distilled but not necessary.

1 out of 1 people think this is helpful.
tenspeed
53,375

Is the heater core clogged? Check both heater hoses for heat. If the hoses are hot, the core bypass door is open. Check the HVAC fuse - the core bypass door is electrical - the temperature knob controls it

1 out of 1 people think this is helpful.
DavidH25
Not Active

Them 3 dudes are right also fyi

judge_roy
Not Active

tenspeed is right. if really you don't need to do this, you shouldn't. perhaps the control just needs to be 'goosed' a bit disassembling and wire brushing things that can be cleaned off.

elvisman4
620

if heater hoses are both hot to the touch you probley have actuator motor bad, remove glove boc liner and there are to actuator there and 1 actuator above accelerator on side of heater case, see if acttuator move when changing from hot to cold, if not remove actuator and move door by hand and if it changes to hot actuator motor bad

3 out of 3 people think this is helpful.
hyster1
10

i forgot its electrical. i was thinking cable. i'll check the fuse, if not i'll be taking the clove box out. thanks

1 out of 1 people think this is helpful.

Your Answer

Add photo

Related Questions

Sierra 1500
Looking for a Used Sierra 1500 in your area?
CarGurus has 62,228 nationwide Sierra 1500 listings starting at $990.
ZIP:

Search GMC Sierra 1500 Questions

GMC Sierra 1500 Experts

#1 dragonflyoffshore
dragonflyoffshore
Reputation 1,660
#2 John Saffrahn
John Saffrahn
Reputation 1,110
#3 Glenn Clingenpeel
Glenn Clingenpeel
Reputation 960
View All

Related Models For Sale

Used Ford F-150"
2,670 Great Deals out of 169,189 listings starting at $1,495
Used Dodge Ram Pickup 1500"
875 Great Deals out of 15,215 listings starting at $1,222
Used Toyota Tacoma"
567 Great Deals out of 21,718 listings starting at $2,199
Used Chevrolet Tahoe"
983 Great Deals out of 33,260 listings starting at $2,500
Used GMC Yukon"
331 Great Deals out of 9,783 listings starting at $2,695
Used Jeep Wrangler"
994 Great Deals out of 45,468 listings starting at $1,800
Used GMC Sierra 2500"
6 Great Deals out of 197 listings starting at $3,900

Used Cars For Sale

2014 GMC Sierra 1500 For Sale
72 Great Deals out of 27,139 listings starting at $18,735
2013 GMC Sierra 1500 For Sale
138 Great Deals out of 2,576 listings starting at $15,995
2012 GMC Sierra 1500 For Sale
142 Great Deals out of 2,590 listings starting at $12,876
2011 GMC Sierra 1500 For Sale
138 Great Deals out of 2,735 listings starting at $10,999
2010 GMC Sierra 1500 For Sale
74 Great Deals out of 1,179 listings starting at $10,950