only high fan

gaftop1 · 11-02-2009, 05:50 PM

changed the evaporator on a 94 c1500 chev. 4.3 auto.changed haven't charged a/c yet but checking things started truck turned on heater
panel looked normal. then,the duct level indicator indicates all levels on and is flashing and blower only has high.
help?

leolkfrm · 11-02-2009, 07:44 PM

bad resister
now you will need to reset the computer by disconnecting the battery because you powered it with low freon(the flashing)

crabtruck · 11-03-2009, 02:18 AM

Welcome to the forum gaftop1.

Sounds like you may not have plugged all the wires back.
Specifically your mode motor and the resistor plugs.
"duct level" I'm guessing you mean mode: heat-vent-def.

Low AC freon warning flash would be the "A/C" light.
Will not happen until detected on attempted use.

Unless you have multiple seperate breaks in resistors,
you should get med#2 as well as hi if as you say hi works.
If lo-and-med resistor was bad and low and med relays
were unplugged, you would lose lo,m1,hi, but m2 would still work.
Symptoms argue relays are plugged in but resistors are not.

Let us know what you find, because usually it IS a bad resistor,
but I really don't think so in this case.
The one other possibility I can think of is that while doing the work,
you put a pull on the harness to head, loosening conection.

This may help you chase wires (drawing is for '94):
AC & Heater Control Problem 91 K1500 Silver

gaftop1 · 11-03-2009, 09:01 AM

the only stuff that was unplugged were the the plugs at either end low on the assembly and the 2 wire 4 pin plug in the middle and the 2 plugs on top of the assembly and the blower motor. everything worked before we took it out.
the blower motor is weak though it screeches at times when first started.
there are 5 or 6 fairly large arrows that are flashing on the disply then a small arrow not flashing that will move to the head or feet.

changing temp from hot to cold will change vents from dash to floor. with floor being cold.
was getting a low pressure code before, but no flashing.
the last thing i want to do in this life is pull the assembly again the only hanging wire i see is a single green wire that went to the ex radio.

Ninja_Lawn_Guy · 11-03-2009, 09:11 AM

WE HAVE ANOTHER ONE!!!!

Maybe not the same but close enough

gaftop1 · 11-03-2009, 02:09 PM

who are you lawnmower boy? if you don't have anything constructive to add. don't chirp.

crabtruck · 11-03-2009, 04:57 PM

Quote:

Originally Posted by gaftop1

who are you lawnmower boy? if you don't have anything constructive to add. don't chirp.

Lawn mower boy is one of our valued members and has just recently
resolved a problem in this area on his own truck.
His comment refers to the number of recent appearances of this type problem
that you could do a search on and perhaps gain some useful leads.
It was not a critisism.
This is a friendly place...chirping is allowed.

leolkfrm · 11-03-2009, 05:17 PM

Quote:

Originally Posted by gaftop1

who are you lawnmower boy? if you don't have anything constructive to add. don't chirp.

you have to watch the heat here, it is all in fun, as crab mentioned when you see the problem enough as it is with gm, it becomes a joke!

park8821 · 11-03-2009, 05:25 PM

i cannot get the two plugs out of the box on the dash can you help me plz

leolkfrm · 11-03-2009, 05:27 PM

Quote:

Originally Posted by park8821

i cannot get the two plugs out of the box on the dash can you help me plz

um totally off the wall, if you have a problem start your own thread, and explain what you need
welcome mr newbee

11-02-2009, 05:50 PM	#1
gaftop1 Full Member Join Date: Oct 2009 Posts: 14	only high fan changed the evaporator on a 94 c1500 chev. 4.3 auto.changed haven't charged a/c yet but checking things started truck turned on heater panel looked normal. then,the duct level indicator indicates all levels on and is flashing and blower only has high. help?

11-03-2009, 02:18 AM	#3
crabtruck Senior Member Join Date: Jul 2007 Location: on your 9 Posts: 3,366	Welcome to the forum gaftop1. Sounds like you may not have plugged all the wires back. Specifically your mode motor and the resistor plugs. "duct level" I'm guessing you mean mode: heat-vent-def. Low AC freon warning flash would be the "A/C" light. Will not happen until detected on attempted use. Unless you have multiple seperate breaks in resistors, you should get med#2 as well as hi if as you say hi works. If lo-and-med resistor was bad and low and med relays were unplugged, you would lose lo,m1,hi, but m2 would still work. Symptoms argue relays are plugged in but resistors are not. Let us know what you find, because usually it IS a bad resistor, but I really don't think so in this case. The one other possibility I can think of is that while doing the work, you put a pull on the harness to head, loosening conection. This may help you chase wires (drawing is for '94): AC & Heater Control Problem 91 K1500 Silver Last edited by crabtruck; 11-03-2009 at 02:42 AM.

11-03-2009, 05:25 PM	#9
park8821 Junior Member Join Date: Nov 2009 Posts: 2	combantion switch plugs need help i cannot get the two plugs out of the box on the dash can you help me plz

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11-02-2009, 07:44 PM	#2
leolkfrm Senior Member Join Date: Mar 2008 Location: N.Y. Posts: 4,300	bad resister now you will need to reset the computer by disconnecting the battery because you powered it with low freon(the flashing) __________________ 4 wheels move the body 2 wheels move the soul B.W.A.I

11-03-2009, 09:01 AM	#4
gaftop1 Full Member Join Date: Oct 2009 Posts: 14	the only stuff that was unplugged were the the plugs at either end low on the assembly and the 2 wire 4 pin plug in the middle and the 2 plugs on top of the assembly and the blower motor. everything worked before we took it out. the blower motor is weak though it screeches at times when first started. there are 5 or 6 fairly large arrows that are flashing on the disply then a small arrow not flashing that will move to the head or feet. changing temp from hot to cold will change vents from dash to floor. with floor being cold. was getting a low pressure code before, but no flashing. the last thing i want to do in this life is pull the assembly again the only hanging wire i see is a single green wire that went to the ex radio.

11-03-2009, 09:11 AM	#5
Ninja_Lawn_Guy Senior Member Join Date: May 2008 Location: Michigan Posts: 413	WE HAVE ANOTHER ONE!!!! Maybe not the same but close enough

11-03-2009, 02:09 PM	#6
gaftop1 Full Member Join Date: Oct 2009 Posts: 14	who are you lawnmower boy? if you don't have anything constructive to add. don't chirp.