Pro Comp 14" Aux Fax Install - '97 LX450

Apr 3, 2006
Littleton, CO
Install of a Pro Comp 14" aux fan (#PC-2053 S), Derale relay (#16763), wired through the A/C pressure switch (no manual switch yet)

Parts Needed:
Pro Comp Fan (#PC-2053 S) + mounting kit
Derale Relay (#16763)
2 Toyota pig tails/terminals (2x 82998-12270)
Appropriate wire, connectors, shrink tubing, in-line fuse, split loom, zip ties, spacers for horn bracket if desired, etc. etc.

Let me start by saying I consider myself a 1 :banana: person...Maybe border lining on the 2 :banana: stage...I envy those that have done this install and stated it was a piece of cake and took them no time at all...

I won't admit how long it took me to complete this but it wasn't just a couple hours :rolleyes: - add in a few hours + typing this up and adding pictures. There is a reason I'm not a mechanic and don't do this for a living...Several times during the install I wished I had just ponied up the $$ for the JDM fan that is apparently a breeze to at least install...I imagine the wiring up portion would be the same regardless. So, choose wisely depending on your situation.

I decided to document this install because it wasn't "easy" for me like it seemed to be for so many others so if there are others out there like me, hopefully this will help. I did a lot of searching and did find a few threads that helped me here and there, but nothing conclusive start to finish. Also, this particular setup seems to be pretty popular lately and while this write up might help on other fans/relays, it is specific to the 14" Pro Comp fan (#PC-2053 S) and the Derale relay (Derale part #16763). I think many have been buying this setup (like I did) off ebay from seller northcoastperf.

This will almost be a step by step by step so hopefully I don't bore everyone to tears (or laughter) - My suggestion is to read through all of the steps to see what I did wrong/learned after the fact so you can avoid some of my missteps that just ate up more install time :p


Step 1:

Flip the fan blade and check for plug polarity...

The Pro Comp fan comes as a "puller" fan and it needs to be converted to a pusher (otherwise you will just waste a bunch of your time adding a fan that won't help :doh:). You convert the fan by flipping the fan blade (take off the nut, flip the blade, reattach nut) and then checking polarity of the plugs so the fans pushes air out the back vs. out the front (puller). In my case (and I imagine every case on this particular fan) the black lead on the fan became my + lead and the blue lead was my - lead. I marked the plugs with a + and - so I didn't have to remember later. I bench tested the fan operation to make sure it worked and to make sure it was "pushing" air with the above changes.

Step 2:

Drill a hole in the bottom of the fan (if desired/required) to drain water. Unless you are positive which way you will orient your fan, this is a step for later in the install so don't forget.


Step 3:

If required, trim/clearance one of the fans mounting tabs that may/will interfere with the hood latch. Again, unless you are positive which way you will orient your fan, this is a step that may be required later in the install so don't forget.


Apr 3, 2006
Littleton, CO

Step 1:

Remove the grill - 5 screws and the center clip


Step 2:

Disconnect the horn leads and remove the horn bracket - 2 12mm bolts



Step 3: (note some claim to have completed the install w/o having to do step 3 & 4 - your choice)

Remove the hood latch - 3 10mm bolts


Step 4:

Remove the center brace - 3 10mm bolts (top, center, and bottom) and the 2 12mm bolts that attach the tranny cooler to the center brace



Step 5:

Trim off, or bend out of the way, the JDM aux fan support bracket that is welded on to the mid/upper left (DS) portion of the A/C condenser. I tried to just trim the bracket first, leaving the welded nut intact. My thought was that in case I ever decided to go with the JDM fan the bracket/nut would still be there. In the end I just cut the entire bracket off. I read where some people bent the bracket out of the way on other aux fan installs with success. I chose to not take this approach because I didn't want to risk bending or damaging the A/C condenser frame and possibly the condenser itself. Bottom line is that the bracket interferes so you have to cut it or bend it out of the way.


Step 6:

Trim the bracket on the lower left (DS) of the A/C condenser. This is the bracket that has a refrigerant line coming off it. I used a Dremmel with a sanding attachment and trimmed off as much as I dared to. Picture showing trimmed off JDM fan tab and trimmed lower bracket.


Step 7: (note: this step may NOT be needed depending on how you are going to attach the fan)

Remove the cross support piece above the A/C condenser. This is the same support piece that needs to be pulled up to install Slee's headlight harness if you've done that mod. LOTS of bolts to remove (IIRC at least 9 in addition to all the other bolts already removed). I chose this path because I wanted to use the mounting kit that can be purchased with the fan and I did NOT want to go through both the radiator and the A/C condenser (although the mounting dealyos are long enough). My future plans may include a supercharger and new radiator. By not mounting through the radiator I will not have to cut and then reinstall the aux fax mounting dealyos should the radiator ever need to come out/be replaced. In the end I still had to go through the radiator for one of the mounting kit ties (PS lower one).


Step 8:

Mount fan to the A/C condenser. I spent a LARGE amount of time here after all of the back and forth with the earlier steps of trimming and trial fitting. I did a lot of positioning, moving the fan around, changing the fan's orientation, trial fitting with the center brace back on, etc. before I decided exactly where I wanted the fan. I used the mounting kit (purchased with the fan) that uses long "ties" that push through the condenser. Right or wrong, I put the foam protector pieces on the back side of the condenser. So I pushed a tie through the foam protector (with sticky side away from the condenser), and then pushed the tie through. I determined where to push the ties through by pushing a different tie through the fan’s mounting tabs and then through the condenser from the fan side first. This way I didn't have to guess where to poke the tie through from the back side of the condenser.

I was able to get the top two ties done easily with the cross brace piece out of the way. The bottom DS tie was a lot more difficult and I had to take the center bracket back off to get more room and then sort of feel for where to insert the tie.

On the PS lower mount I couldn't figure out how to get this "tie" in short of taking the condenser out. I was just going to leave it off but in the end I decided to go through both the radiator and the condenser on this one tie. In fact, what I ended up doing was drilling a hole through the lower left mounting slot (i.e. I didn't use the tab that you push onto one of the slots in the fan) and using that spot on the fan. Not perfect but the best solution I could come up with. It was a PITA trying to get that tie lined up close enough to go through the hole I drilled in the tab. Looking back it would have been easier to just push the tie through the fan’s tab, through the condenser, through the radiator, and put the tie lock piece on the radiator side of things...Maybe that is how all of them are supposed to be installed but I couldn't find any directions on how to use the mounting kit and having never done something like this before I had to guess at how it is supposed to be done. Anyway, I used the same process of pushing a tie through from the fan side to figure out where it would come out on the radiator side so I knew where to start from the opposite direction. That last tie did not come out in the exact spot in the end but it came out close enough to work.


Step 9:

Reattach the cross brace (if removed), center brace (if not already done), and the hood latch. I figured out AFTER the fact that I had to clearance one of the fan mount tabs (top right) for this - see picture. If you install your fan oriented the same way as I did, do yourself a favor and trim that tab while the fan is off the truck - it will be a lot easier.


Here are some additional pics of the fan and how tight it is in there…





Step 10:

Reinstall the horns. The fan will be in the way so you need to decide if you are going to bend the horn bracket or horns to clear the fan or you can take my approach which was to space the bracket away to clear the fan. If you have done the spare tire mod then this is similar. I measured how far away the bracket needed to be and then ran to my local Ace hardware for longer bolts and spacers. In the end I used SAE flange head bolts (vs. metric) that were 3/4" longer than the original bolts, a lock washer, and a 3/4" steel spacer between the bracket and the cross support piece with a washer in between the spacer and the cross support piece. The horns just clear the fan and just barely clear under the hood when closed. As a bonus one I was able to use one of the original horn bracket bolts to attach my relay to the truck ;p (see later step)




Last edited:
Apr 3, 2006
Littleton, CO

First off, wiring....Ick :hillbilly:

That said, I chose to wire up my fan based on Sumotoy's write up using the A/C systems high pressure switch (ABC's of 80's Cooling Part III - Press Switch) and with the after run feature. After a lot reading I felt this was my best choice. I have not yet, but may, install a switch inside the truck at a later date so that I can turn the fan on at will. I didn't do this yet because (A) I wasn't sure how to with this relay (I'm relay illiterate), (B) I wasn't sure what type of switch I need, and (C) I needed to save something for later (read that as I was dang tired of working on this by now) the first thing I noticed is that the Derale relay is "different" than the typical 4 pin relay that Sumotoy references in his thread. I'm guessing (or read?) that the Derale is a "5 pin" relay. So, I had to make myself a cheat sheet or conversion chart:

4 Pin vs Derale (5 pin?)
Pin 30 = Pin 30 (Red wire, 12v + Battery lead)
Pin 85 = Pin 86 (Yellow wire, 12v + Trigger/Switch Power lead)
Pin 85 = Pin 86 (Green wire, 12v + A/C clutch lead)
Pin 86 = Pin 85 (Black wire, 12v - ground lead)
Pin 87 = Pin 87 (Orange wire, 12v + to fan)
------ = Pin 87a (nothing/empty)

As you see, there are some differences and an addition to the typical 4 pin relay. Based on this I determined that I needed to wire the Derale relay and fan up this way:

Pin 30 = To battery + (with appropriate inline fuse of course)
Pin 85 = To one side/lead from the pressure switch (other pressure switch lead to chassis ground)
Pin 86 = Yellow wire to battery + (for after run feature - I didn't fuse this lead?)
Pin 86 = Green wire to nothing - Might be able to run this to a switch in the cab?
Pin 87 = Orange wire to fan + lead
Fan - = to chassis ground

I drew up a schematic on a piece of paper to help as well...If I had better drawing skills I'd make up a schematic to post but I don't so I won't ;p

Here are some steps and pictures of my wiring job...Obviously the relay location, ground location(s) used, etc. will vary from install to install. You could run the fan off an aux battery (which I might have done if I had an aux battery at this point in time). The consideration here is that the pressure switch is on the DS of the rig so your ground run from the relay to it would be a long one assuming you mounted your relay on the PS by the aux battery. If you mount the relay on the DS to be close to the pressure switch then your + leads to the battery will be the long ones...Pick your poison.

Step 1:

I started by (in no particular order):

* Picking a location for my relay - found the perfect location behind the DS headlamp/cross brace that had an existing threaded hole that just happened to require the same bolt size as one of the now spare horn bracket bolts I had. I had to slightly increase the size of the relay's mounting hole...more fun with the Dremmel...
* Picking a good chassis ground location
* Attaching an inline fuse (30 amp) to the relay's pin 30 wire
* Adding a section of wire to the relay's pin 87 (orange) wire to reach the fan (the relay's wire came up about 12" short of what I needed)
* Attaching the relay's pin 85 ground wire (black) to one of the Toyota terminals (the relay wire length + the terminal wire length was perfect for me to reach the pressure switch from my relay location)
* Attaching a section of black wire to the other Toyota terminal for chassis ground
* Making up a section of fan ground wire to run to chassis ground


Step 2:

Once I got done with all the preliminary wiring fun/connections, I started wiring stuff up.

First, I temporarily bolted the relay where is was going to go and ran/routed the fan + (orange, pin 87) lead to the fan, cut the wire to the right length and put on an appropriate connector.

I then routed the fan - ground wire (with appropriate connector on the fan end) back up the same route the + lead took. I put some split loom around these wires and zip tied it all to the center brace and the lower valance piece.

Step 3:

Wiring up the pressure switch connections: First you have to get the connector off the pressure switch. On the back side of the connector (toward the front of the truck) is the "release tab". You push on that while wiggling the connector down and off. You end up with this:


Following Sumotoy's write up you need to push out the two black filler plugs. I used one of the little metal inserts from an old wiper blade…You know, the flat metal inserts that help the rubber blades retain their shape and hold the rubber to the blade body? Why I kept them I don’t know but they came in handy! My straight pick was too big to fit down in there.

Once the plugs are out you then take the relay's pin 85 black ground wire with the Toyota terminal attached and insert it into one of the vacant slots (making sure you have the wire routed the way you want it to be first so you don't have to try and get that sucker back out). I installed the pin 85 ground lead into the side of the pressure switch connector that faced the fan since that is where my relay sits in relation to the pressure switch. The other side I used for chassis ground which happened to be on that side of the pressure switch :) - I put both the fan ground and the pressure switch ground into one ring terminal, crimped, and shrink tubed them (put the shrink tube on before crimping on the ring terminal :D). Then I routed those to the existing DS fender chassis ground next to the battery tray and bolted it down.

Note: in Sumotoy's write up he mentions to make sure the retaining clip divot on the terminal plug is facing to the outside of the connector. Not sure why but in my case the retaining clip on the connector is to the INSIDE of the connector body so in my case it was reversed from Sumotoy's directions. Also, one of the terminals went in easy but to get the other terminal in I actually had to pull out (gently pry up using a 90 degree pick and alternate from side to side) the interior retention plastic doohickey. I'm sure there is a technical term but if you've ever worked on the NSS connector or similar there is a piece inside the connector that locks down on the terminals in addition to the retention clip inside. You can see this piece on the connector - it is the white piece in the above picture.




Step 4:

Battery + connections: All that was left for me now was to wire up the + battery leads. I took the red pin 30 lead (with in-line fuse) and the yellow pin 86 lead and, just like on the ground wires, I put these into one ring terminal, crimped, and then shrink tubed them. I put some split loom over the wires and routed then to the positive battery terminal and attached the ring terminal.

Relay location and back side view of existing hole with welded on nut:



Install fuse, put the grill back on (if not already done), and then fire up the truck, put the AC on max, and wait until the pressure builds and the fan comes on (hopefully). My fan came on in less than 5 mins at idle. Shut down the truck and check to see if the after run feature works. In my case my fan ran for all of 5-10 seconds after I turned the truck off.


As mentioned before I have not yet wired in a manual switch. Sumotoy mentions to tap into the pressure switch ground lead going to pin 85 (on the Derale relay, pin 86 on the relay Sumotoy used) and then to a switch and then to ground. Sounds simple enough but I have this extra green wire on pin 86 of the Derale relay doing nothing. I'm wondering if I can wire that up a switch in the cab :confused: According to the relay instructions the "Green Wire (pin 86) is: Optional - Attach to the Positive lead from the A/C clutch. This will allow you to turn on the fan every time the A/C is turned on". Well, seems like I can use this lead to wire up to an in cab switch but maybe the pressure switch grounding would interfere with this somehow. :meh:

Results...First off it worked :clap: - I was extremely pleased to hear that fan come on after all that effort. I've only driven the truck a couple times. Once to work with the A/C off and I never noticed the fan coming on and it didn't run after I shut the truck off. On the way home from work I had the A/C on (low) and although I never heard/noticed that the fan came on during the drive, it was on when I pulled into the driveway and it ran after the truck was turned off for ~30 seconds.

I hope this install thread helps others out there like me :cool: - If you see any errors/problems let me know so I can keep the original post accurate :steer:
Sep 15, 2006
Vidor, TX
Nice write up. I did this same install and yours is much neater than mine. I need to clean up my wiring. And don't feel so bad about how long it took you, my buddy and I, working together, took a full day to do this to both of our trucks. The second one went much faster.
Sep 17, 2003
Sunnyvale, CA
Nice writeup.

I installed my procomp fan about 2 months ago - pretty well the same fitment issues. Yes, the fan is a TIGHT fit and does require some trimming of bits here & there to fit well. Once in there it isn't going to move anywhere...

I did my install over a few days. Did the wiring one day then a test fit of the fan another and then final install on another day. Makes for a much smoother install since it gives you time to reconsider each decision step :)

Works great and I've seen after run of 3 minutes when everything including ambient is HOT. Excellent addition when running a/c and driving slowly on the trail when it's hot & dusty outside.

I used a standard relay and mounted it on the inside fender just in front of the main battery. There is a bolt that holds a factory ground connection - good spot to wire the relay and its associated ground connection and keeps it out of the way.

Apr 3, 2006
Littleton, CO
Another one for the list of FAQ's

nice and clean install:cheers:

Thanks for the nice comments everyone :)

As for whether this is FAQ worthy, we'll see if Romer deems it so and adds it in :cool: - I could always bribe him with a :beer: at the next after club meeting "meeting" :hmm:
Apr 3, 2006
Littleton, CO
Romer has favorites. :frown:


If that were true he would have adopted me by now :p - Romer, like everyone else tends to get busy with life and I doubt he gets a chance to read every thread...My suggestion is that if you have a good install thread to send him a PM to get it added to the FAQ's :beer: - I've done other install write ups that aren't in the FAQs but no biggie - just having them on MUD for others to find in the main intent anyway.
Apr 3, 2006
Littleton, CO
Robbie, aka powderpig, gave me a great suggestion that I thought I would pass along.

Robbie suggests getting a fin comb and straightening the fins on the A/C condenser (and tranny cooler as well). He believes that would help as much as the fan itself will. Wish I had thought of that before I installed the fan.

I'll probably make an attempt on straightening out the fins on the tranny cooler though (looked into replacing it but a new one is $350+) while contemplating how badly I want to take off the fan and while looking for ideas on coming up with a way to protect it from bugs and rocks etc...maybe some screen material attached to the back side of the grill or something?

Users who are viewing this thread

Top Bottom