Heater Problem
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From: St.Louis area

At first the blower would come on intermittently, now its not turning on at all. I put a test light on the wires going to the blower there was no power. Next I swapped the ECC out for a different one and still no blower. I need some help with this one. Thanks
Originally Posted by jberg6
At first the blower would come on intermittently, now its not turning on at all. I put a test light on the wires going to the blower there was no power. Next I swapped the ECC out for a different one and still no blower. I need some help with this one. Thanks
The blower control module is held by two screws. You can check the blower motor itself with a fused wire from the battery and ground to be sure it'* working okay? Some people suggest hitting the blower itself enough to vibrate it witht he power on and sometimes they will start working, usually temporarily.


Be sure to diagnose the blower motor and check for power to the blower control module before replacing parts>[/img]
Originally Posted by jberg6
At first the blower would come on intermittently, now its not turning on at all. I put a test light on the wires going to the blower there was no power. Next I swapped the ECC out for a different one and still no blower. I need some help with this one. Thanks
Originally Posted by jberg6
I looked in the book for a fuse for the blower and didn't find one. I'll check the blower control module next.Thats gotta be it. thanks guys
If it is also dead on highest speed it is likely something other than the Control Module, which is used to slow the motor from high speed. It should get bypassed in HIGH.
The ground for the motor (and the blower control mod.) is via the passenger front fender above the battery. Take that loose and clean the ends of all the black wires.
If your ECC is the same as my 93, the other common item is the dashboard HVAC control panel (yuk).
My schematic also shows fuse 17 (25 amp) as being a common requirement for all blower speeds. This is in the fuse block under the dash near the steering column.
If it runs on some speeds but not others, it will point towards something else. So knowing that is important.
Again, all I have is manual for a 93, so just crossing my fingers that the items above are common to your year.
Bill
The ground for the motor (and the blower control mod.) is via the passenger front fender above the battery. Take that loose and clean the ends of all the black wires.
If your ECC is the same as my 93, the other common item is the dashboard HVAC control panel (yuk).
My schematic also shows fuse 17 (25 amp) as being a common requirement for all blower speeds. This is in the fuse block under the dash near the steering column.
If it runs on some speeds but not others, it will point towards something else. So knowing that is important.
Again, all I have is manual for a 93, so just crossing my fingers that the items above are common to your year.
Bill
Originally Posted by jberg6
push button ECC
It also has two other related fuses that go to the programmer which feeds the voltage to the lblower control module: Fuse 5A for 15 Amperes whic is labeled also as Aut A/C Cruise; and Fuse 9C which 10 Amperes and labeled MSC/RDO/CLSTR. The last one is keep alive, I believe.
There is no separate relay that powers the high speed setting with direct current from the battery instead of through a resistor pack as is on the basic HVAC unit.
Have you tested the blower motor itself? Always start with the simplest explanation. Law of Parsimony.
EDIT: I missed a fuse. There'* a fuse in the right side passenger fuse/relay block. It'* #11 and is 10 amperes. It'* the feedback fuse from the line to the blower motor that tells the programmer what voltage is b eing applied to the motor by the blower motor control module.


