When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
We (son and I) purchased an 86. While cleaning up corners and nooks to diagnose a slightly lumpy idle, we found the relay for the cooling fan had rusted out. This relay uses 4 pins. They are marked: On, comm, coil and coil.
We bought a common 4 pin relay which is marked with numbers.
2 terminals are copper and 2 are silver color.
we did establish which of the 2 cause the relay to click by applying 12v and ground.
My wiring diagram does not show exactly the same wire colors and i am trying to determine which go to which terminal.
Sadly (or foolishly) I pulled the 4 connectors from the female harness without noting which wires went to which stock point son the old relay
(figure black is common but the other 3...)
We are trying to establish which wires are 12v at start and which receive a signal from the thermo switch (and where is this switch)
From the diagram, looks like the fan gets 12v at all times and the connection is closed at the relay so.
So, I am trying to find which of the two wires go to the coil terminals.
Any help would be appreciated.
There are two relays in the system thus which one are you needing help with. Is it is the one located alongside the other relays at the nose of the car?
The relay in question is behind the right retractor headlight, underneath the stock air filter and airflow sensor.
Wouldn't that be the air-bypass relay? The two relays for the electric auxiliary fan would be side by side and in front of the radiator. They are denoted in the diagram as being f-75 and ac-05. 75 has the following wire colors; Yellow/Black, Black, Black/Yellow and Green/Red (Black/Yellow is powered constantly by the meter fuse). Relay 05 has a Yellow wire powered constantly by the fan fuse, a Green/Red wire, a Blue/Orange wire and a Green/Blue wire.
We had thought it was the fan relay, because we got continuity between the pins and some of the fan wires using an ohmmeter. Either way, the fan is not engaging so my next step would be to check all of the front relays to see if they're functioning.
As for the relay we are trying to connect, could it be related to the lumpy idle? Recently its been more of an oscillating idle. Between 1000 and 1500.
I may also check the thermoswitch to see if it is not closing to activate the electric fan. Can it be put in boiling water, and at what temperature does it usually open?
The fan turning on and off might affect the idle a bit due to the voltage being used but it's likely not your problem. The TPS needs to be set right and that might be contributing to a lumpy idle. If the relay you found is actually for the air bypass well that relay helps the bypass solenoid and BAC to inject more air into the engine. And what are the colors of the wires you are dealing with at this relay?
The colours are black, black with white stripe, red with yellow stripe, and brown with yellow stripe. They also have blue bands.
P.S: Thanks for the link Satch, that should help me check the fan relays later when I get a chance.
I'm 100% certain that your pic is of the air bypass relay (refer to non turbo EGI &emission control system diagram and look at the illustrated view of the ECU and below and to the right is that specific relay. Runs to pins 1C and 3I).
09-21-16, 07:46 AM
