Hey guys i read ******* article but im still a bit confused. Right now niether of my fans work. The primary one will kick on when grounded. I want my car to run cooler for the summer and was reading the tech articles. First, for the secondary fan. All i need to repalce is the fatory sensor in the head to get teh fan to come on? Y is my fan not coming on even when the a/c is on could this be becuase that sensor in the head is bad? Second, is it hard to wire the primary fan into the stock wiring? It doenst really say in his articles

 

To test the primary fan the easiest way is to run the diagnostic codes. Jump the ALDL connector like you are retrieving codes and while it runs the codes it also should turn on the driver or primary fan as a self test. That tells you the relay and all wiring is OK. Forget what you read on the article about manual fan control, don't bother, it's a waste of time and effort unless you are racing. If you get a lower fan switch for the aux fan or pass side fan and it has a turn on temp lower than 220 degrees BOTH fans will run. When the aux fan is turned on before the ECM detects 220 degrees it will default and turn on the driver fan automatically. A very common problem with the 89's are the fan relays. Get 2 new relays from either NAPA or GM. They are redesigned units and are more reliable. The relays are notorious for working intermittently and will drive you nuts looking for other problems. Trust me, it's worth the small investment. Remember this also, with a lower aux fan switch the fans because of their high current requirement will place more stress on the charging system making the generator work harder and run hotter. The CS gen's are famous for running hot anyway. As far as the AC is concerned if the primary fan runs with the ALDL connector suspect something related to the AC system. Thats a separate issue you can address later.

 

K the primary fan comes on when jumping the terminals but the car reaches about 240 and it still will not come on. Im thinking of goin to buy that hayden kit from pep boys which is in ******* artilce (the turn-on relay). Will this fix the problem? Y is the fan turning on with the terminal jump but not when hte car gets hot. Also, by replacing the fan switch on the head of the secondary fan will that one work even though its not right now? I think the relay is bad for the a/c or sumthing which is y the fan dont work.

 

Come on guys i need help here. THe primary(drivers side)fan comes on with terminals ground but not when temp goes over 228*. The cts is new from autozone. WHat else could be the problem?

 

We are trying here. The fan comes on during diagnostic check. That tells us the ECM, fan relay and motor are good. You say you changed the coolant temp sensor, where was it. I am not trying to belabor this but many guys have inadvertently changed the guage sender thinking it was the CTS. The CTS on the 89 has 2 wires and should be on the front above the water pump screwed into the intake manifold. The ECM has direct control over the driver side fan, it's the only thing that controls it. Guage sender is on the driver side above cyls 1&3 and has one grn wire. Aux fan sw on pass side above cyl 6&8, also one wire. Does the AC comp come on? Basically what you are experiencing should not happen. Is the guage correct. When AC is requested 12 volts is fed thru the press cycling sw to turn on the comp, my book shows some models with a relay some direct. Either way 12 volts goes to the comp clutch and also that same 12 volts goes to an input on the ECM which in turn turns on the fan. Unless we are dealing with some goofy software issue within the ECM itself(very unlikely)there is a clue missing. Get back to me with more info, I"ll try to come up with anything I can think of.

 

Yes, i replaced the cts. Its in the spot in which u described so i dont believe that is the problem. Unless i got a faulty sensor but i dont think that is the case. THe fan still comes onif i ground the 2 terminals but has yet to come on if the temp is over 228. I dont think the gauge is the problem becuase i can see steam coming from the radiator when the temp gets to high showing signs that the fan is not working. ALso, the a/c fan does not work. It may either be the switch or the relay because it will not turn on witht he a/c. You think it could be a problem with the ecm? I hope not, is there any way to test that? How could i test the cts to see if thats working?

 

Well i unplugged the cts sensor and the car ran like it does in the morning before it warms up but the fan DID come on. Any suggestions it wont come on with the sensor plugged in. Anyways im sure the gauge is working ok because when i poped the hood when the gauge read 240 there was steam coming from the radiator. Any suggestions

 

If you get a lower fan switch for the aux fan or pass side fan and it has a turn on temp lower than 220 degrees BOTH fans will run. When the aux fan is turned on before the ECM detects 220 degrees it will default and turn on the driver fan automatically.




Danno, are you positive about the above statement ?

I have an '89 bird 5.7 TPI and was curious how to get the ECM controlled fan to come on at the same time as aux fan controllled by my lower temp fan switch .........if you are right they will both come on together ????

Plz ack and thx


Bill E.

 

Yup, been there and done it. Thats why I went back to the factory setup. Look at the fan diagram for the aux side, when the fan sw or AC pressure sw calls for it to run there is also a wire going back to the ECM. When that wire goes low before the primary fan is called for the ECM detects a fault turning on the primary as well. In fact if you go back on the cooling boards you will see it a lot.

 

Is your system holding pressure?

 

yes system is holding pressure just fine. New radiator, cap, water pump. The fan just doesnt want to turn on.

 

ttt

 

Sorry I fed you some (as we used to say in the Corps) bum-scoop. cycling the key is for Chrys. As I said I had a splitting head-ache. Anyway I checked the Alldata Site and this is what I got for your current problem. Note; This also relates to your other Post!!!

If coolant fan does not run at all, perform test A. If coolant fan runs at all times with A/C off and engine cool, perform test B.

Test A: Coolant Fan Open Test

Connect fused jumper between ALDL connector b terminal and ground and turn ignition switch to RUN position. If coolant fan runs, problem is ECM related. If coolant fan does not run, connect fused jumper between coolant fan relay connector dark green/white wire terminal and ground and turn ignition switch to RUN position. If coolant fan runs, check dark green/white wire for open. If wire is satisfactory, problem is ECM related. If coolant fan does not run, disconnect coolant fan relay connector, turn ignition switch to RUN position and connect test lamp between orange wire terminal and ground. If lamp does not illuminate, check fusible link H and orange wire for open. If lamp illuminates in steps a and b, disconnect coolant fan relay connector and connect fused jumper between orange and black/red wire terminals. If coolant fan runs, replace coolant fan relay. If coolant fan does not run, leave fused jumper connected as in step 4, disconnect coolant fan connector and connect test lamp between terminals as follows: Connect between black/red wire terminal and ground. If lamp does not illuminate, check black/red wire for open. Connect between black/red and black wire terminals. If lamp does not illuminate, check black wire for open.
If lamp illuminates in steps a and b, replace coolant fan.

Test B: Coolant Fan Short Test

With ignition switch in RUN position, remove C/H-FAN fuse.
If coolant fan turns off, check dark green/white wire for short to ground. If wire is satisfactory, problem is ECM related.
If coolant fan does not turn off, replace coolant fan relay.

Troubleshooting Hints:

Check C/H-FAN fuse if coolant fan does not run.
Check that ground G112 (2.8L/V6-173), G117 (5.0L/V8-305 VIN E) or G104 (5.0L/V8-305 VIN F and 5.7L/V8-350) is clean and tight.
Check fusible link J (6 cylinder) or H (8 cylinder).
If coolant fan runs with ignition switch off, replace coolant fan relay.

Service and Repair:

After filling cooling system, start engine and allow to reach operating temperature with radiator cap removed. Air in system is bleed through radiator cap opening. Add coolant as necessary to bring to proper level, then install radiator cap and check coolant level in recovery reservoir.

They are some other diagnostics I could post but looking at the problems your having I thank you nees to check out the ECM. Is this a custom chip or is it stock. Also removing a spark Plug Wire on the EFI cars can send a voltage spike through the ECM/PCM.