(88 gta trans am 350 hsr with ac) Hey everyone i got a big problem with my 88 gta. Yesterday i had to replace the hi/low blower relay its a 5 pin relay now on my car the wiring connector was burnt from the previous owner so i had to wire my own connectors i went the same way as the factory connector would plug into the relay. So i though i had it all working correctly but when u set it to the highest setting its pops the hvac fuse under the dash also no all the other speeds work great except i noticed smoking coming out of the ac box in the engine compartment so i disconnected all hvac stuff and the battery and it made the smoking stop thank god. Another thing i have going wrong as well no matter what when i turn the hvac control off the blower is still running im very confused about this where would the fault be where should i start checking i do have basics electrical diagnostic tools (test light, volt meter, power probe) so i think i would be able to figure it out

 

Sounds like the relay is wired wrong.

The circuit is really quite simple:
The blower motor has one wire to it for power. It goes to the "common" contact of the relay. This is the contact that the relay then connects to one of the other 2 terminals.

There are 4 switch positions for fan speed, and 4 wires coming from it, one corresponding to each position. The 3 for the lower speeds go to the resistors. The "output" (that's not really what it is, but that idea will get the point across) goes to the "normally closed" contact of the relay, such that when the relay is not energized, power passes through the switch, through the selected resistor, to the NC contact of the relay, through the contacts to the C contact, and on to the blower motor.

The 4th wire from the switch, for high speed, goes to one side of the relay coil. If the relay has an internal diode, this wire needs to go to the side of the coil that the arrow of the diode points toward. The other side of the relay coil goes to ground. When the switch goes to high speed, it sends power there, energizing the relay, and causing the contacts to switch over.

A big fat red wire brings raw battery to the "normally open" contact of the relay. When operated, the blower motor is disconnected from the resistors, and instead gets hard battery, thus making it run as fast as possible.

Hook it up like that, it will work right. Assuming of course that there's nothing else wrong with any of it, and that nothing got burned up by being hooked up wrong. If it doesn't work right, then ....

 

"Another thing i have going wrong as well no matter what when i turn the hvac control off the blower is still running im very confused about this where would the fault be where should i start checking i do have basics electrical diagnostic tools (test light, volt meter, power probe) so i think i would be able to figure it out"

The blower motor, when properly hooked up, will run on a low speed when switch is on the lowest setting. IIRC it had something to do with carbon monoxide/ fumes or something. Mine runs also

 

Ok so no matter what position on the hvac control the blower motor will work doesnt sound right but if thats the way it is on the digi dash cars then i guess thats how it works, (first time owning a digi dash car) but it shouldnt work in the other speeds with the hvac control on the off position.

And now for the ho/low blower relay connector i did each wire exactly like the plug connector would plug in from the factory (cut and rewired each wire 1 by 1 in the proper spots i must have a short somewhere else in the harness or either that the resistor is bad and giving to much resistance thats my only guess

 

Bump ok figured the problem out it was the wrong hi/low blower motor relay thanks for the help everyone