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-   -   fan switch wiring? HELP (https://67-72chevytrucks.com/vboard/showthread.php?t=18176)

jones 07-11-2002 09:57 PM

fan switch wiring? HELP
 
1 Attachment(s)
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

1 Attachment(s)
Here is a Pic

jones 07-11-2002 11:34 PM

1 Attachment(s)
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

1 Attachment(s)
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

1 Attachment(s)
did I say the forecast was for 110???


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