I did the mod, and it improved blower speed. It was clearly noticeable in the vents at the lower rear of my console.

Spoiler: Cruiser is writing this up as one of his "tips". Watch for it. Highly recommended.

 

Here it is:


The blower motor's factory grounding point is on the driver side inner fender under the sheet metal screw. This ground is shared with windshield wipers, front windshield washers, rear windshield washers, AC clutch relay, fan control relay, fog lamps, fan motor, headlamps, front turn signals, front side markers, and park lamps.

So your blower motor has its ground point 10 feet away from where it is located!!

What we’re going to do is leave that ground intact and also ground the blower motor on the passenger side inner fender much closer to the blower motor itself. This will also benefit the other components on the factory ground circuit. Take this opportunity to refresh the factory ground as a matter of course.

Here's what I do to get the ground much closer to the blower motor and add another ground point to this overloaded ground circuit.

Find the blower motor connector on the passenger side. Red and Black two wire connector.

Find a location where the black wire can be made to reach the passenger side inner fender, and cut the wire. You may have to do some rerouting of the harness to achieve this.

Take both cut pieces of wire and put them together into a yellow eyelet and crimp. Fasten the eyelet to a place on the passenger side inner fender with a sheet metal screw. There’s probably one on there that you can use. Be sure to scrape the attaching point on the fender to bare metal first.

Your blower motor will now turn faster and last longer, and the other electrical components on the circuit will benefit from a better ground path.

 

Thanks Cruiser. Since I just replaced my blower motor & resistor ,this is something that I have to do.

 

Some research still going on. Perhaps the 91 and later had the grounds on the engine block. I'll know more later today and then change the write-up as needed. For sure 87 to 90 need it. I haven't looked into the 86 and earlier.

 

Wait,I have a '94.
I thought there was a short black wire that was bolted to the firewall.
I would have to remove the washer tank to inspect.
See below.are these the wires you are referring to?

 

I'm not sure if that's where the blower motor grounds on a 91 and later, or if it's a ground for something else. I've got a buddy looking into it.

Anyone have a wiring diagram of that vintage that can verify?

 

I know this is an old post but.

My 96 doesn't blow all that hard. Fan sounds like it is blowing normal though. My resistor was messed up and it only worked on high. I bypassed the thermal fuse and now it works on the other speeds. Is it possible to clean the Evaporator mesh without pulling the hvac box? My assumption is that there is something in there blocking airflow.

 

all good questions, I have these jobs to do on my 96
NOTE; I bought a $3 thermal fuse rated 133C that I read on another forum can be soldered in place of the original and usually restore the resistor pack assembly to full operation

 

My resistor pack is working fine now that I bypassed the thermal fuse with a piece of wire. This is in a trail rig and not a DD, so I'm not too concerned about the safety features of the thermal fuse. All of my positions work now. I was going to just buy a new one, but none of the parts stores had a resistor in stock, so I just said the heck with it and bypassed the fuse. Works fine lol.

I'm going to pull the blower motor out when I get home and check for blockages. I'm going to hopefully get it blowing better...We have our first decent snow on the way...3-6 inches and I'm wanting to go play...Figured I would try to get the heat working a little better first lol.

 

I know this is an old post but I am wanting to do the same thing. Where I live normal temp goes as high as 110f so my stock ac blowe needs an upgrade.

Did you manage to upgrade it and how is it compared to what you had before. I dont want to do it myself as I dont like to mess around with electric stuff, so id like yo know what should I buy to have it done.

 

@cruiser54 my harness has a black wire and a orange wire with a black stripe… the side going into the harness close to blower motor is black and green. Is this the right one?

 

black to black

 

instead of cutting the wire, could I strip
some of the insulation off the black wire and connect a new wire from the grounding point? To allow for less movement of the original wiring harness.

Essentially have a new ground wire coming from the sheet metal screw and then connect into the original ground wire. i was thinking about just using one of these.

 

Sure