Quick question: Fan relay

[Tim]

Going to the junkyard tomorrow for parts to fix my radiator fan. Pretty sure the relay or temp sender is bad.

Quick question: Where on the Festiva is the radiator fan relay? What does it look like? Is there a different relay for different years?



Did a search and couldn't find a wiring diagram or clear answer to my question.

My car is an 89 Auto with the funky EFI. The Pull 'n' Save has 2 88's and a '92 Festiva.


Thanks!


Tim

[GenevaDirt]

I believe it is the one in the thermostat housing. I think the temp sensor is the one in the head just down and to the left of the housing.

[Tim]

I believe it is the one in the thermostat housing. I think the temp sensor is the one in the head just down and to the left of the housing.

Thanks for the info.

However, I'm looking for the relay that turns on the fan. I have reason to believe mine is stuck/burnt out.


Regards,

Tim

[GenevaDirt]

if you disconnect the wire from the plug on the thermostat housing....does the fan run? If so....it is the switch.

[Tim]

The fan runs with the wire on or off the terminal.

You think it might be the temp sensor that's bad?


Regards,

Tim

[GenevaDirt]

if it runs...the relay should be good...IMO...sounds like connection to the sensor....could be broken inside and acting as if it is disconnected and letting the fan run.
I did find from a quick search on google that the fan relay is behind the drivers headlight.

[mattswabb]

The relay is mounted on the inner fender wall on the drivers side. Between the fusible links and the headlight, but closer to the headlight.

[Tim]

Thanks for the advice!

I'll check both the temp sensor and the relay.


-Tim

[zoe60]

When I got my '89, the previous owner had added a wire from the fan to the battery to make it run all the time. I got rid of it and replaced the fan switch on the head next to the thermostat and the problem was solved. Seems dumb when unplugging the switch wire makes the fan come on anyway. If you are a new owner check wiring closely, people do some tricky stuff sometimes.

[Tim]

Mine was jury rigged with a chunk of 8 gauge wire and a welding ground clamp.

To turn the fan on, the previous owner clipped the welding clamp to the driver's seat rail.

It wasn't fused and seemed like a pretty dangerous setup, so I took it apart. It looks like the engine wiring harness wasn't touched, only the fan plug was snipped off.



Regards,

Tim

[FB71]

Tim, some quick diagnostics for you. You may know some of this already, but for those at home who are following along;

The relay has four wires;
large Black (blk) = ground wire
large Yellow/Red (ylw/red) = switched ground to the fan motor
Black/Yellow (blk/ylw) = +12v from 'Meter' fuse in dash, hot with key in 'Run'
Green/Red (grn/red) = switched ground from the CTS (Coolant Temp Switch)

The fan runs, so the large blk and ylw/red wires should be ok. There's a slight possibility that the ylw/red is shorted to ground, circumventing the relay. To check, unplug the fan and relay, then check for continuity to ground with a multimeter.

Next, make sure you have +12v on the blk/ylw wire with the key on. Don't assume you do. The relay is OFF when the fan runs. The relay turns ON to turn OFF the fan. If the relay has no power, the fan will run continuously with the key on (the fan also gets positive voltage from the key in the 'Run' position).

Last, check the continuity of the grn/red from the CTS to the relay. If the wire is open, that will cause the fan to run constantly.

Basically, if you ground the grn/red wire at the CTS and the fan turns off, the CTS is bad. If not, check all the wires. If they check ok, the relay is bad.

[Tim]

Thanks for the help everyone!

I went to the junkyard today and pulled the temp sensor off a wrecked '92 GL Sport (that's another story.. ), as well as what I think is the fan relay - a metal box with 3" of wire and a round connector on the end. I also grabbed a relay from an '88, but it has a rubbed boot and square plug on the bottom.

It appears that the temp sensor was the culprit. I put the new one in, and the fan stays off with the wire connected/on with the wire removed. I won't know until spring if the new sensor is any good though.

I also noticed that my old sensor, which I assume is original, is physically larger and longer that the one off the '92. Any reason for this? They interchanged fine though.


Regards,

Tim

[FB71]

I also noticed that my old sensor, which I assume is original, is physically larger and longer that the one off the '92. Any reason for this? They interchanged fine though.

different supplier. Very common with Asian cars to switch suppliers, or have several suppliers for the same part..

[Tim]

different supplier. Very common with Asian cars to switch suppliers, or have several suppliers for the same part..

Interesting. I remember you mentioning something about the rear spindles changing on later models due to suppliers, so that makes perfect sense.


Regards,

Tim