Just a thought for you.

On the last heater blower I bought, the power plug was a 'universal' one
that could have the negative in either of the two pin positions. If I
had of gotten it wrong, I would blow the fuse instantly like you are
doing.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Aug./05 http://www.imagestation.com/album/in...?id=2120343242
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"Julie P." wrote:
>
> Hi, I have five questions (below). Both the blower motor and radiator fan
> for my '91 Chevy Cavalier 2.2 liter no longer work, even though I replaced
> both motors last week. The 25 amp AC/Heater fuse blows every time as soon as
> I turn the key to "run" with the heater on. I must have a short.
>
> After studying the wiring diagram, it seems the radiator fan and blower
> motor are on the same circuit.
>
> The wiring for this circuit goes as follows:
>
> Wire from Ignition Switch to
> 25 amp Heater/AC Fuse
>
> Then from this Fuse, wire to Splice A, with two wires coming out of this
> splice (wires 1 and 2 below):
>
> Splice A Wire 1:
> From Splice A to
> Heater Control Switch then to
> Blower Resistor then
> through the firewall then to
> Splice B: one wire to blower motor and the other to the blower relay
>
> Also, redundant ground from Blower Motor to Main Ground at Tranny Bolt
>
> Splice A Wire 2:
>
> From splice A through firewall then
> to Coolant Fan Relay then
> to Alternator input sensor
>
> [end]
>
> QUESTION 1:
> So does this mean the short must be between Splice A above and the ignition
> switch?
>
> QUESTION 2: If so, why does my alternator still work then, since that is
> also at the end of this same circuit??
>
> I am at my wits end, as I was forced to purposely break my plastic center
> console in multiple places, just to access the blower motor switch. I was
> considering taking a Sawzall to it to get enough access. See, my shift stick
> knob would not come off, even though I pulled out the U-Pin. So I had no
> choice but to break the console into pieces to get to the blower switch.
>
> QUESTION 3: How do I get my shift stick know off if it is stuck on?
>
> Then, I was not able to perform the Chevy recommended diagnostic procedure
> with my DMM, since as soon as I turned the key to run, the fuse blew!
>
> And it is almost impossible to inspect the wiring, since the clusters are
> completely wrapped in electrical tape and very hard to access, even with the
> panels off, due to a metal support frame. It would take my hours just to
> remove the tape.
>
> And there is molten lava-like black gunk covering everything where my wire
> harness enters through the firewall. I thought is was dirt, but it feels too
> rubbery. It prevents me from seeing the wires at some points.
>
> QUESTION 4: What is this gunk?
>
> And now I have to remove the glove box and passenger side trim to access the
> blower resistor.!
>
> QUESTION 5: When will all this insanity end? All this just to find a short?!
>
>
> Thanks for any help!
>
> Julie