my hvac blower motor stoped working then i changed it and still dont work where is the relay that controls the fan located on the box right next to it maybe?

 

the relay is only for the high speed blower setting, all the other settings use the resistor bridge. Does it work in any of the speed settings or in none?

 

works in none of the settings so what does that mean?

 

Yes, the relay is close to the fan on the HVAC housing. Be aware, the relay only controls high speed. The lower speeds are all powered through the resistor which is also right by the fan motor. To verify the problem, you need a test light.

Test for 12v at the purple wire to the fan motor with the key on and fan on high. Be sure throughout these tests that the AC control is not in the "off" position. If no power at the purple fan power wire, test for power at the red wire of the relay. Then test for power at the orange wire of the blower relay.

If there is no power at the red wire, look for a bad fuse link at the supply end of the red wire. This may come from the starter or from a junction block. If no power at the orange wire, look for a blown HTR/AC fuse in the fuse panel. If fuse is good, suspect a bad switch. If you have good power at the purple wire, check your ground connection to the fan. If ground and power are good to the fan, you have a bad fan motor.

 

i have no ground at the black wire conection what do i do

 

any ideas?

 

ground it to some metal. body , frame, engine, etc....

 

i did that it made little shocks but no spinny fan the fan is brand new i just got it today

 

ok tomorow il put a bat charger to the fan terminals see if she spinns

 

ok i jumped my fan and it works when i hardwire it to the batery but what would cause the ground wire not to ground which side of the power is the resistor pack that controls voltage to the fan for selective speed positive or negitive side because i dont understand why my ground would go out im very confused by this

 

 

The fan should by grounded to a body ground close to the HVAC housing. Your 87 has a plastic HVAC housing so the housing cant be grounded. You have to run a ground to the body ground that should be just to the right of the housing, on the firewall. Look carefully at your wiring. The black wire was connected to a ground from the factory. Probably at the rear of the pass side cyl head or at the body ground mentioned above.

 

ok i started fresh today and realized i have no ground at all the black wire is disconected were dose this wire conect to the chassis to make the ground? thats were ill start

 

Try this link for some more info on blower motors and connectors.

https://www.thirdgen.org/forums/elec...aro-rs-no.html
I was getting low and medium but no high-speed. Found the culprit with help from this post. Good luck!

 

G112 is the ground that supplies the fan motor. Its on the rear of the pass side cyl head. If your car has AC, which it sounds like it does, you will play heck getting to that ground with everything in place. I recommend using the ground on the firewall instead. Look for the ground strap from the engine. Attach the fan ground where the strap attaches to the firewall.

 

ok im completely confused now ive been tracking this ground for about two hours it goes into a conector out the other side into a small harness then into one of the main harnesses behind the coil and dis cap and i can not trace it any farther there is no loose wire hanging around and now im just baffled it looks as if it were going to the drivers side of the bay

 

any ideas why it wouldnt be were its supose to be?

 

Can you add wire to the ground you have and touch it to any metal?

 

i can jump the ground and everything works but i dont like leaving lose ends around so i would like to find it are you shure its supposed to be mounted back of pass side head?

 

I'm not going to say I know exactly what your problem is but if you need your heater blower, seal the bare wires and run it to a bolt or any bare metal securely for ground. Make a permant fix when there's time.

 

i had the same problem last year . i did all of the above to no avail . went back to fuse panel/power source . traced power from there . found problem & repaired same . remove trim around HVAC & radio , slide out/remove radio . looking into center console where radio was you will see a larger than others , grey wire . it will have a white disconnect inline on it , it's the power feed to the fan switch . mine had become corroded and was not sending pwr. to fan sw. . i cut out disconnect , put in a crimp connector , my problem solved . check for power with a probe or multi meter . ign.sw. on for power , off for repair . hope it works for you . good luck .

 

That's right Tom, there's one just like it on the left side of the firewall with the same cheesy connector that will be burned inside when you unplug the two clips. Mine was light grey.

 

everything works except the ground for the dam thing (the wire has no continuity to the chassis or battery so why did my ground drop off the radar is what im asking)

 

ok this what im talking about to the left is the from the conector and to the right this ground goes into the harness going behind the coil. is this were it is suposed to go or is it going into strange places

 

ok does anyone have a wiring diagram for this ground so i can figure it out its becoming neerly imposible to trace it as you can see in the pic above dont have much room to open harnesses and trace it

 

My factory manual shows C112 at the rear of the pass side head. It is not a bad repair to replace the ground circuit from the blower motor to the engine or a good body ground. The problem you face is that the grounding points on either cyl head are very difficult to access with everything installed. I always try to attach these grounds as I'm lowering the motor into position. That's why I suggest you perform a quality splice to the existing ground wire where it goes into the loom and run the new wire to the ground location where that strap shown in the photo attaches to the firewall.

This is how we would handle this repair at the GM dealer.

BTW, a "quality splice" is either done with solder and heat shrink tubing or a heat shrink sealed butt connector and good crimping pliers like Klein brand. This way we avoid having issues with this repair down the road.

 

would it hurt anything if i splice ground and leave the other wire lerking around were ever it may be i mean it is a ground but i wish to be sure

 

Oh crap! I was just rechecking my factory diagrams. G112 is on the pass side head on engine code G or H. On engine code 8 or F it's on the rear of the LH, or driver's side head. I was looking at what else uses that ground cicuit. The blower motor is grounded by a small black wire that runs to the blower relay where it is spliced to a larger black wire. That large wire goes through a 2 pin connector, C105, that is located on the right hand side of the engine compartment. That large wire is attached to the rear of the driver's side cyl head.

I appologise for being old and absent minded. Thank you for staying after me so I finally got the right information.

 

well i cut the wire already so should i just conect to the ribon were the block is grounded and pretend the wire dose not exist to the other side i dont realy care if the wire to the other side is in the harness and its ok i still dont undersand why GM moves things all over the dam place between models

 

sorry actualy when i removed AIR crap me being a dumass forgot to put the wire back

 

LOL. Hey it happens to us all. I hope I was of some assistance. Happy motoring.