fan switch wiring? HELP - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jones · 07-11-2002, 09:57 PM

please help -

question:
I can't get the fan to blow - but the relay clicks (until the fuse blows 15-20 sec.)
how do I wire my blower fan switch?
or could something else be going on?

background:
when I got the truck the wire plug at the switch was melted - and so was the switch. I've replaced the switch, the resistor & the relay. I couldn't get 12v from the 18g brown wire that was at the switch so I ran a new fused 14g wire to the switch for power. that leaves me with a thick 14g yellow, a thin 18g yellow with red stripe(assuming it would be the orange one in the diagram), and a thinner 18 or 20g light blue wire. I've tried connecting them as per the diagram but the fan won't run - just a clicking relay. I put a jumper from the batt to the fan and it turned fine (although the jumper wire got very hot)

what am I missing (besides the skill to find this problem)?

one wiring diagram I got says there are 5 wires?
the diagram in my haynes manual says there are 4?

please see attached pic and comment. thanks in advance
J

Huck · 07-11-2002, 10:15 PM

Had similar problem which was solved when GMC Paul told me to re-do the grounds --both at the heater relay and at the fan motor. I suspect that if the jumper wire to the heater is getting hot----you have a grounding problem. Is this an A/C truck?

RipMeyer · 07-11-2002, 10:15 PM

To start I would try to run the same gage wire all the way.
Lemmie check my factory manual.

RipMeyer · 07-11-2002, 10:45 PM

Here is what I found under my dash.

#1 Yellow

#2 Orange

#3 Brown

#4 Lt Blue

RipMeyer · 07-11-2002, 10:58 PM

Just confirmed from the factory manual. What I have is correct.

RipMeyer · 07-11-2002, 11:07 PM

Here is a Pic

jones · 07-11-2002, 11:34 PM

thanks all!
Huck
it's an AC truck-
grounds are all ok (bypassed them with jumpers)

RipMeyer
thanks for the pic
I just hooked it up according to what yours is
#1 Yellow
#2 Orange
#3 Brown
#4 Lt Blue
see pic

and the fan runs in the 2nd click from the top(position 3?), but nothing at the 1st & 3rd click from the top(position 2 & 4)
the relay clicks loudly and the 4a fuse I had inline blew (replaced with 15a)

ideas???

jones · 07-11-2002, 11:35 PM

this is what I have for wires...
the blue one is shorter because the end was burnt

RipMeyer · 07-12-2002, 12:15 AM

After looking at the diagrams the only thing I could suggest is the Resistor, Relay and the Switch. Seeing as you already replaced those, maybe you fried one of them when it was hooked up wrong. Switch is more than likely ok but the resistor and the relay may have been damaged.

jones · 07-12-2002, 11:01 AM

wierd -
I re-connected the wires to the switch, re-re-checked the grounds and this time it works.

YAHOOOO

no I just wait for the duracool to show up so I can charge this baby and go. today's high forcast at 110. It's not suppesed to get this hot in Idaho.

anyway, thanks for the input RipMeyer & Huck - it helped to get the wires plugged in to the right spot.

RipMeyer · 07-12-2002, 06:58 PM

GOOD JOB!!!

Thats why we all hang out here.

jones · 07-12-2002, 09:05 PM

did I say the forecast was for 110???

07-11-2002, 11:07 PM	#6
RipMeyer Registered User Join Date: Oct 2001 Location: Southern New Mexico Posts: 649	Here is a Pic Attached Images

07-11-2002, 11:34 PM	#7
jones Registered User Join Date: Jun 2002 Location: North Idaho Posts: 43	thanks all! Huck it's an AC truck- grounds are all ok (bypassed them with jumpers) RipMeyer thanks for the pic I just hooked it up according to what yours is #1 Yellow #2 Orange #3 Brown #4 Lt Blue see pic and the fan runs in the 2nd click from the top(position 3?), but nothing at the 1st & 3rd click from the top(position 2 & 4) the relay clicks loudly and the 4a fuse I had inline blew (replaced with 15a) ideas??? Attached Images

07-11-2002, 11:35 PM	#8
jones Registered User Join Date: Jun 2002 Location: North Idaho Posts: 43	this is what I have for wires... the blue one is shorter because the end was burnt Attached Images

07-12-2002, 09:05 PM	#12
jones Registered User Join Date: Jun 2002 Location: North Idaho Posts: 43	did I say the forecast was for 110??? Attached Images __________________ 69 C15 86 K20

07-11-2002, 09:57 PM	#1
jones Registered User Join Date: Jun 2002 Location: North Idaho Posts: 43	fan switch wiring? HELP please help - question: I can't get the fan to blow - but the relay clicks (until the fuse blows 15-20 sec.) how do I wire my blower fan switch? or could something else be going on? background: when I got the truck the wire plug at the switch was melted - and so was the switch. I've replaced the switch, the resistor & the relay. I couldn't get 12v from the 18g brown wire that was at the switch so I ran a new fused 14g wire to the switch for power. that leaves me with a thick 14g yellow, a thin 18g yellow with red stripe(assuming it would be the orange one in the diagram), and a thinner 18 or 20g light blue wire. I've tried connecting them as per the diagram but the fan won't run - just a clicking relay. I put a jumper from the batt to the fan and it turned fine (although the jumper wire got very hot) what am I missing (besides the skill to find this problem)? one wiring diagram I got says there are 5 wires? the diagram in my haynes manual says there are 4? please see attached pic and comment. thanks in advance J Attached Images

07-11-2002, 10:15 PM	#2
Huck Senior Member Join Date: Jun 2001 Location: Shelbyville, KY Posts: 3,269	Had similar problem which was solved when GMC Paul told me to re-do the grounds --both at the heater relay and at the fan motor. I suspect that if the jumper wire to the heater is getting hot----you have a grounding problem. Is this an A/C truck?

07-11-2002, 10:45 PM	#4
RipMeyer Registered User Join Date: Oct 2001 Location: Southern New Mexico Posts: 649	Here is what I found under my dash. #1 Yellow #2 Orange #3 Brown #4 Lt Blue

07-11-2002, 10:58 PM	#5
RipMeyer Registered User Join Date: Oct 2001 Location: Southern New Mexico Posts: 649	Just confirmed from the factory manual. What I have is correct.

07-12-2002, 12:15 AM	#9
RipMeyer Registered User Join Date: Oct 2001 Location: Southern New Mexico Posts: 649	After looking at the diagrams the only thing I could suggest is the Resistor, Relay and the Switch. Seeing as you already replaced those, maybe you fried one of them when it was hooked up wrong. Switch is more than likely ok but the resistor and the relay may have been damaged.

07-12-2002, 11:01 AM	#10
jones Registered User Join Date: Jun 2002 Location: North Idaho Posts: 43	wierd - I re-connected the wires to the switch, re-re-checked the grounds and this time it works. YAHOOOO no I just wait for the duracool to show up so I can charge this baby and go. today's high forcast at 110. It's not suppesed to get this hot in Idaho. anyway, thanks for the input RipMeyer & Huck - it helped to get the wires plugged in to the right spot.

07-12-2002, 06:58 PM	#11
RipMeyer Registered User Join Date: Oct 2001 Location: Southern New Mexico Posts: 649	GOOD JOB!!! Thats why we all hang out here.



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