Hey everyone, new to the forum. I have an 89 RS 2.8L. I'm having some issues with my fan not turning on and my temperature gauge. In the process of trying to get my fan to work, my temperature gauge is now constantly pinned in the red. It would go back to zero when I turned the car off, but now it's always pinned whether the car is on or off. I replaced the coolant temperature sensor with no luck. I also replaced the temperature switch on the driver side head just behind the AC compressor. It had one green wire leading to the switch. Still no luck with my gauge. Could it be the gauge itself or maybe a short circuit?

In regards to my fan, I connected the fan directly to the battery to guarantee the fan still works properly and was in luck. I tested the leads into the fan and had a steady 12 volts so I know I'm getting power to the fan. What else should I check? I know there is a relay near the driver side firewall but I'm not sure how to check that everything is working properly. Any suggestions?

 

Check to make sure the relay works by applying power to the wire that comes from the ecm, aka back probe the relay. then you know that the entire circuit works.

If just the coolant temp gauge is pegged I believe it sounds like a ground problem. I was seeing my temp gauge peg or not read once and I noticed that while putting the valve cover back on I had torqued them down with the wire between the head and valve cover. Woops.

Could also take a voltage meter to the wires from the sensor and get a reading and make sure it is in line with what the temp should be. IE it could be a 0-90 ohm resistor with 0 being 0* and 90 being 300* or something.

 

Which wire do I apply power to? Is it the red wire in the bottom of the relay? When I do, will the fan turn on if there is nothing wrong with the circuit?

 

You replaced the fan temp switch, not the sender for the gauge.

Fan temp switch is rear of pass side head.
Coolant temp sender for gauge is front side of drivers side head also with single wire.
Coolant temp sender for ECM is under the throttle body.

I would recommend replacing your fan relay if its original. I have an 89 2.8 as well and the original fan relay went out in 09, bout 20 years it lasted. Went through the same thing as you.

How exactly did you test the fan?

Edit-your temp gauge will also most likely be off anyway once its fixed.

 

According to what you said, I replaced both of the coolant temp senders.

I tested the fan motor by hooking it up directly to the battery to make sure the motor was still good. When I tapped the positive lead to the battery, the fan started spinning. I also tested the wires that plug into the fan and was receiving 12 volts. I will be buying a new fan relay this weekend.

Do you have a part number for the fan temp switch? I tried searching for it on autozone but all I could find was a cooling fan switch on the radiator.

 

Someone else may chime in with the part number, there are actually a couple threads in here with part numbers if you take a look. AFAIK there are no fan switches that go into the rad on any thirdgen, so that may just be it. Dont take my word for it though...

If you replaced both sensors, than it could be the fan switch, or the relay, or both for that matter.

 

You may not be aware but there's also a Thermo switch next to the temp sensor that may be bad.

 

Thanks for letting us know after 11 years...

 

Well, I just joined yesterday! It's easy to tell you're a complete piece of work. If you want a more updated forum you may want to join social media. This forum is years old within itself! Growl at someone who cares!

 

Kick rocks, fool. You call Me a "piece of work" while YOU are the one who replied to someone in a 11 year-old thread. Nobody here owes you ANYTHING...

 

Anger management may assist with that condition! I didntvrealize how old the thread was but updating any information is what the 11 year old thread is still afforded from the administrators, I would think.

 

You are the one who got angry, instead of just admitting your mistake.
And you added NO updated information.
But go ahead and continue with your attitude...

 

I didnt make a mistake. I added to a forum via the title. You were very rude from the first reply. You could have ignored it but you were so disrespectful you couldn't resist. Hopefully, someone else sees your rudeness. Have a Blessed day!

 

Again, you added NOTHING of any benefit to this 11 year-old thread. Go back to Facebook where you belong...

 

I'm here to stay. Who do you think you are. This is a car group. Gather yourself! You aren't worth the reply. Enjoy being miserable! Ma'am 😆

 

Great, so we can look forward to more words of wisdom from you on ancient threads.
Should be of great help to those who originally started them...