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Old 11-13-2003, 02:18 AM   #1
crackajacka
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blower motor problems narrowed down

ok i hooked the battery straight to the blower motor and it blows like no ones business. so i looked and the switch all it does is connect to that silverish module on the side of the a/c unit what is that called and how much is it to replace?
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Old 11-13-2003, 02:33 AM   #2
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generally it's the switch in the heat control thats bad . you can do a simple continuity check on that or just jump wire past it to see if 12V is coming that far. There is also a fat wire(orange?purple?) that runs to the blower motors for the high speed because that is almost direct. (no resistance) just passes through the switch. DAVE
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Old 11-13-2003, 02:40 AM   #3
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are u talking about the one wire that plugs into the blower motor?
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Old 11-13-2003, 03:08 AM   #4
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yes, it passes from the switch inside to a resistor bank for the lower speeds but high speed is direct. sometimes when the resistor block goes bad you will still have high speed. if the switch is bad you won't have anything. Check fuses? .DAVE
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Old 11-13-2003, 03:13 AM   #5
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well i had high for about 45 minutes then i had nothing
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Old 11-13-2003, 03:29 AM   #6
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sounds like it took the fuse out at that point?
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Old 11-13-2003, 03:33 AM   #7
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all the fuses in the fuse panel are ok they are all new
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Old 11-13-2003, 08:13 AM   #8
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after i put my new blower in ..it wouldnt work until i put a fuse in the air cond and the heater slot .... worth a try
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Old 11-13-2003, 10:57 PM   #9
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The connector lugs on the blower relay (the little silver box) and on the resistor on my Sub are prone to corrosion, so every year I have to clean them (or at least wiggle them) before the heat will blow. The contacts inside the relay also are a bit finicky, & when they don't conduct, nothing blows. Sometimes a good thump on the cover will fix it for a while.
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Old 11-13-2003, 11:34 PM   #10
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My dads 98 Silverado lost everything but High. He changed the resistor block and it was cured...for a month or so, now only high works again.
If you have nothing at all id try bypassing the switch to see if its bad.
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Old 11-14-2003, 10:26 PM   #11
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i would have to disagree, its almost never the interior switch :/ in my experiences anyways..

but yeah its probably the relay thats giving you problems..

jimfulco hit the nail on the head when he said they are finicky and prone to corrosion.. The resistor tends to rust and then disintegrate also, so I would replace them both.. they're not expensive. If you still cant get it working, let us know and we'll get it straightened out, the circuit is really quite simple

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Old 11-15-2003, 02:50 AM   #12
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ok whats do i need to ask for at the parts store when i go to get another resistor.
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Old 11-15-2003, 06:09 AM   #13
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blower motor resistor and blower motor relay

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Old 11-15-2003, 11:28 AM   #14
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Quote:
Originally posted by crackajacka
ok whats do i need to ask for at the parts store when i go to get another resistor.
I suggest you take your old one in and show it to them. That might save you a couple of trips.

Everytime I go to the parts store without the old part, I get to go back for the correct part. Sometimes twice...
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Old 11-15-2003, 01:24 PM   #15
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Ken's right , even with the carb number in hand i was not able to come home with the right choke parts for my 85 the first time.
They have superceeded many part numbers into one more 'generic' number for old vehicles such as ours.. DAVE
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Old 11-16-2003, 01:03 AM   #16
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It just occurred to me that sometimes the function switch (heat, defrost, etc.) on mine has to be in exactly the right place for the fan to blow. Give everything a wiggle before you drop a bunch of cash.
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Old 11-16-2003, 01:30 AM   #17
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well its the resistor thing, i can pull the plug then jump the connections with a piece of wire and select high,med,low,lowlow and connect 2 ports and it blows on that setting
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Old 11-16-2003, 09:26 PM   #18
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still not blowing grrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr, replaced the resistor and still nothing? what do i need to check next? n how
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Old 11-18-2003, 02:12 AM   #19
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The blower switch. Have you used a multi-meter and checked all the wires?
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Old 11-19-2003, 05:14 PM   #20
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i dont know if i understand the problem here but the switch in the dash sends power to the high speed relay "little silver box on side of the a/c box" if you have power there the dash switch is good. the high speed relay is the problem if you jumped the curcits and it blows. you can get one at any parts store for $15 or less. we sell them at O'Reilly's for under $15.00. the problem with my burb was it wouldnt work on high. pulled one off another truck and it works fine now. good luck and hope this helps!
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