AC Condenser Fan Upgrade (from a 90-95 4runner)

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Jul 31, 2007
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516
Location
San Diego North
I still see quite a few 3.0 90-95 4runners in the junkyard and have been upgrading my 92 pickup with creature comforts like
map lights
full gauges
AC
int wipers
clock
ash tray and glove box light
oil pressure sender
dash speaker enclosures

I noticed a while back that the 4runners have an AC electric condenser fan behind the grille so I finally got one and decided it must be bolt on like everything else. Well, it wasn't quite bolt on but I did it anyway. The lower part of the Radiator support where the fan and bracket bolts to on the 4runner is different on the pickup and would explain why it is stamped "PU" on my pickup. There was an existing 10mm hole where the top of the fan attaches but I had to weld 3 nuts to the lower support for the bottom 2 fan mounts and the new hood release support bracket.
I read elsewhere you would need the bumper and grille from the 4runner but I only got the fan, wire harness, and hood release bracket.
The wire harness includes it's own relay(2) and fuse box that attaches to the existing fuse box nicely via slots in my 92. The harness also includes a resistor and 2 ground points. It appears that the fan has 2 speeds depending on conditions.

fan1.jpg

fan2brackets.jpg
 
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Joined
Jul 31, 2007
Messages
516
Location
San Diego North
I had to trim the grille but not the bumper. It fits nicely. Ill add to this once I wire it up. Ignore the foam, it's helping hold the grille while the black silicone dries cause the grille clips suck. Time to build a stronger bumper or protection as I feel like I just installed a damage multiplier. A minor front collision could push this into the condenser easily.

fan3weldnuts.jpg


fan4installed.jpg


fan5installednutview.jpg


fan6bumperonwithfan.jpg
 
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Joined
Jul 31, 2007
Messages
516
Location
San Diego North
Wiring
The factory wiring harness for the fan has 3 wires you need to deal with. I have included the factory diagram as well as a simplified diagram I made as all anyone really needs to know is what the 3 wires do coming off of the harness. The fan will normally run on low when the ac clutch is activated. The 4runners have a normally closed high pressure switch in the condenser line that triggers the fan to high when pressure builds during high demand/temps. The pickups don't have this so something like a normally closed snap disc/thermo switch could be used to trigger the fan to high when a certain temp is reached.
Basically when both the black/white and green wires have a positive signal to the relays, the fan will be on low, when the green wire positive signal is removed, the fan will be on high. The first picture shows how neatly the condenser fan relay/fuse box slots onto the existing pickup fuse box.

condfanwiring4.jpg




condfanwiring1.png


condfanwiring2.png

condfanwiring3.jpg
 
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Joined
Jul 31, 2007
Messages
516
Location
San Diego North
I ended up connecting both the green and black/white wires together to the AC clutch wire and the yellow wire to the battery. The fan turns on low when the compressor clutch engages.
I will test it out this upcoming summer and see how it does. Low moves a good amount of air and high is pretty obnoxious so I may just leave it this way.
I did consider adding a switch to the dash to activate high but I'll probably use a snap disc like the one below, just need to find the right temperature and placement.

This is the type of normally closed snap disc that can be used in place of the 4runner high pressure switch(also normally closed). you can choose the temp you want the fan to go to high. the snap disc would be attached to the condenser or radiator. this one would turn the fan to high at 194 deg F.

condfanwiring5.png
 
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