Doc279

I am having trouble with my air conditioning on my 1990 V-6 4 runner.
The wiring diagram shows a A/C cut off relay but I can't find it on the runner.

Does anybody have a Toyota service manual ? Both my Clymer and an old Chiltons manual mentions the relay and gives a testing procedure for the relay but the location is never revealed. It's not in my owners manual either.

eric-the-red

I have the full factiry manual in pdf file, I can email you any or all of it. It's for a 95 but should be the same for all 2nd gen. Send me an email address and I'll send it to you when I get home tonight.
It shows the A/C cut relay as being on the right side of the dash, behind the glove box.

Doc279

Thanks Eric

dstaley@searay.com is my work address. I've looked behind the glove box in fact it is still in the back seat. I found the A/C fuse and the heater fuse
along with the 40 amp circuit breaker. I did'nt see a relay but I ain't perfect.

abalagtas

Hey Doc,

What kind of problem are you having? I'm having problems too and can't find the components.

My problem is the AC only comes on when Flex-a-lite fan comes on. Normally, the Flex-a-lite turns on the AC via the AC idle up circuit.

frankenrunner

hey, Doc279,

according to the FSM, not only is the "A/C cut relay" located behind the glove box, it is behind the glove box & on the RIGHT SIDE of the A/C cooling unit/evaporator assembly (the big black box on the left of the two that are there) in the form of a round plug (think "extension cord").

continuity should be tested between terminals #1 & #3 & if no continuity, replace. if there is continuity, apply battery voltage between terminals #1 & #3 & then check for continuity between terminals #2 & #4. again, if no continuity, replace.

if everthing tests out o.k., then you need to look elsewhere.

hope this helps!

Doc279

The compressor never kicks on - engine speed don't matter.
When I removed the grille - found that the ballast resistor in the fan circuit,
had both wire connections corroded off - ballast was ruined.
I bought another ballast resistor at Advance Auto Parts - universal one.

It did not correct the problem - touching the wire to the bumper would turn that electric fan on - I started the engine and set the A/C to MAX and touched the wire to the bumper - thinking that the fan and compressor were on the same circuit - compressor still does not energize. I know that my problem is electrical and not freon related. I tested the compressor and clutch wire with a jumper wire from the battery - clutch compressor immediately locked up and lines get cold - also have cold air at the vents.
I did not leave the wire on there but just a minute or so. Connection for the compressor lead was unplugged from the harness and power applied there. did not want to apply voltage back through the rest of the components.

This acts like a blown fuse - everything works but the compressor clutch does not energize - I checked for voltage at the compressor plug and there is no voltage. Switch at the dash tests good - even robbed one from my neighbor to swap and test.

4Crawler

iTrader: (3)

There is a low pressure switch behind the glove box:



Mine is jumpered on since my A/C is dead, I use it to boost the idle speed when needed. There is also the "A/C Amplifier" that has an "RPM" adjustment knob on it. That sets the RPM below whel the A/C is cut off (to avoid bogging down the engine). Should be set just below the normal idle speed.

Bigblock

there's a fuse above the computer.also i think only 4 cyl have an a/c cut relay,not v6

Doc279

I found the culprit ! The A/C relay failed the test - continuity was supposed to be read between 1 - 2 - 3 post continually - voltage applied is supposed to bring in post 4 It does not.

I fabricated a jumper to post 1, 2, and 3 - with the engine running and A/C on max - touched pin 4 with my jumper - clutch locked up and the condenser fan came on - COOL !

Now I have to get a relay - thanks for the pointers !!!!

Oh - it was mounted on the heater / blower box directly behind the glove box.
The relay is rubber enclosed and hanging on a pin bracket.