Fans - coolant - overheat still

[Umaro]

Im sorry for asking all this crap again but I still havnt gotten any clear answers.

1) Engine overheats if its just sitting there idle, or if I drive it.
2)I realized the coolant over flow bottle is completely filled
3)The fans will NOT turn on, even with the a/c and heat turned on, neither one will turn on.
4)I just realized, that the birdcage/coolant light is turning on.

Question 1 - How can the coolant light be on if the overflow tank is all the way full?

Question 2 - What would cause both fans to stop working and not be able to be turned on by turning on a/c and heat, what exactly can I test to see whats wrong?? Could anything involving the coolant make it so both fans wouldnt turn on?? Or are they two different problems.

Sorry for bringning this up again, but I just want to be able to turn on my car without it overheating.

 

[BUCK]

3)The fans will NOT turn on, even with the a/c and heat turned on, neither one will turn on.

Check big fuse (middle one I think) at Battery fuse block - That's the only thing I know of that could kill ALL fan functions.

 

[Umaro]

Checked it, and even tried other working fuses in there, still no go.

 

[BUCK]

Check Fan Connector at Passenger side, top of Radiator - this can get wet & corroded from Overfow Bottle mess - Power for BOTH fans comes thru here.

If I recall correctly 2 pins on that Connector Power Coolant Switch & Rad (pass side fan) so if car is hot you have a dead short so be careful - if cool circuit is open - Other 2 pins Power AC fan - apply Power from small Battery Charger at that Connector with small Alligator clips to fan side of Connector - If you hit the pins wrong fans run backwards so pay attention.

 

[Umaro]

Ok I will check that in about 2 hours.

Also, you have any thoughts on the coolant problem? Would it be a stuck therm?

 

[BUCK]

Originally posted by Umaro
Ok I will check that in about 2 hours.

Also, you have any thoughts on the coolant problem? Would it be a stuck therm?

Yes - just change Thermo out if you pull it - Overflow Float Switch is stuck or Connector has fallen off - catch my edit above too!

1990 Schematics:

http://www.ecanfix.com/users/mdhamilton/1990schematics.html

 

[Umaro]

"If I recall correctly 2 pins on that Connector Power Coolant Switch & Rad (pass side fan) so if car is hot you have a dead short so be careful - if cool circuit is open - Other 2 pins Power AC fan - apply Power from small Battery Charger at that Connector with small Alligator clips to fan side of Connector - If you hit the pins wrong fans run backwards so pay attention."


Alright, I didnt completely understand what you said here.... .. mainly the first part.

 

[BUCK]

Originally posted by Umaro
Checked it, and even tried other working fuses in there, still no go.

We ARE TALKING the Fuse Block right AT the Positive Connector - CORRECT? The Middle Fuse Powers all fans!

 

[Umaro]

Yes, the box with the 3 fuses in it, I switch the fuse in the middle with the ignition fuse and tried to turn on the fans and it still wouldnt work.

 

[BUCK]

Did you swap out Rad Fan Relay in Pass side Fuse Box with AC fan Relay from Driver's side at Firewall fuse Box? - If not - do so immedialtely! Note that Rad Fan still won't run till Engine gets Hot - OR - the smart thing to do would be to pull Temp Switch Connector at Bottom passenger Radiator & "jumper out" Connector to make Fan circuit think Car is Hot & fan will run provided it has Power (Ignition switch ON - Pull MPI fuse) - I would probably jump this out FIRST for ALL your troubleshooting evolutions - it's easier than burning gas & worrying about car overheating -

 

[Umaro]

hmmmmm... I think I may have did that a few days ago, but I Will do it right away when I Get to my car in about an hour and tell ya what happens!

Thanks for the help by the way.

 

[BUCK]

Clean Fan Connector above the Overflow bottle & Check Overflow Connector under the Overflow bottle while you are down there - I WONDER if you can plug OVERFLOW Connector INTO FAN connector? Seems like they are similar & DAMN close to each other!!!!!!!!!!!!!!

Install Temp Switch jumper, wire - 2 small Alligator clips - like your Timing jumper...
Make sure Middle Fuse is good.
Pull MPI fuse.
Swap Relays.
IGN to ON - NOT ACCESSORY! - No need to run car.
Rad Fan should Run.

If Not - - A meter would be nice here~~~~~~!! Small battery Charger with a Gauge set to Low Amp makes a good "ghetto-meter".

CAREFULLY apply power & ground to 2 of the 4 Rad Fan Connector Pins till a fan runs - If you don't have a meter to ID the 2 Temp Switch Pins Just TOUCH IT OFF on pins because you have 2 of those pins SHORTED at Temp Switch! Let's NOT cook anything! You have to leave Temp Switch jumped out for Fan to Run with Engine Cold - Check Fan rotation.

 

[Umaro]

Well, just had to car towed to my house, and guess what, it wont start!!!

It wont turn over, all my gauges light up when I try to start it up, and the coolant light comes right on.

Im completely screwed now if the car wont even start.

 

[Umaro]

David - says:
yup, well like I said, the fans will not turn on, even when the ac/heat is put on, so they dont work, therm isnt working so I can even let it idle or it will overheat within 5 mins
Lucky says:
did you tap on the thermostat housing
Lucky says:
while its running after its warm
David - says:
Didnt even have a chance, but its not the thermostat Im worried about, its the fan, the thermostat has nothing to do with atleast the a/c fan not turning on
Lucky says:
yes it does
Lucky says:
the thermo stat opens and send a electronic signal to the fans then they turn on


Is this guy right, would a stuck therm stop the a/c fan from even turning on?

 

[TimG]

I have the same problems dude. I have to have both my fans on all the time because my FMIC is too large and block a lot of airflow.

My fans decided one day to stop working and I'm looking for he answer.

And YES, they should come on no matter what. As long as you push the button with the snoke flake on it, with the heater/AC fans on full blast.

 

[Umaro]

That stinks, I was hoping someone would say yes, thats correct if you change the therm the fans will start working....

well, if either of us figure out whats wrong, make sure to post.

 

[TimG]

Ok Dan Sontag. Will do.

 

[BUCK]

Lucky: the thermo stat opens and send a electronic signal to the fans then they turn on

Lucky is full of shit.

 

[Umaro]

Its Dave, and obviously you got that from ca.* cuz your from Toronto. heh

 

[painmaster]

I know this was already stated but you should check the temp sending unit on the passenger side bottom of radiator. If this sensor goes out the fans will not come on.

 

[Umaro]

How do I check this???

Im making a road trip to pick up some parts so I need to know what stuff I should ask for to fix up my problems, heh.

I already have thermostat, heat shields, rad cap on my list.

 

[painmaster]

The temp sensor on the bottom of the radiator is nothing but switch. It shorts itself when the temp goes over 185F and then once temp goes below 172F it opens the switch.

So to test if this is the problem, unplug the wires to the sensor and jumper them together. If the key is on and wires jumpered then the fan should start up.

 

[painmaster]

Here is pic of the sensor, if it came through!

 

[Umaro]

UPDATE!

I went and picked up a thermostat, rad cap and coolant.

I took out my old thermostat and put it in boiling water and it opened up, so I got pretty worried cuz I thought it was a stuck therm... and since it wasnt stuck that could be trouble.

So anyways, I replaced the thermostat, then I replaced the rad cap and I compared it to my new one, and I realize, there was a crack in the rubber at the very top of the inside of the cap, so I replaced that and put some more coolant in.

Started up the engine and no coolant light, and guess what, the god damn fans turned on when I turned on the a/c.

So then I let the car sit to see if the fan would turn on by itself and after a while it did.

So problem seems to be fixed, now on to find out where oil is leaking.

Thanks to all that helped out and replied to my threads.