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Topic: electric fans/ac inop (Read 5683 times) previous topic - next topic

electric fans/ac inop

Reply #15 –
I have the 87 EVTM, so our pages don't match.
ECA (Electronic Control Assembly) is another name for EEC (Electronic Engine Control).
I guess technically, EEC includes all the things the ECA controls and all the sensor inputs to the ECA.
It's located behind the passenger side kick panel.

electric fans/ac inop

Reply #16 –
dang. thought I might have missed a component to check.  Considering both fans work, what component am I missing that is not turning them on when I either 1. turn on the AC, or 2. the engine gets up to temp.  I am trying to find a common component that may be broken.  Is there a way to test the Engine Coolant Temp sensor?  I swapped it out, but if it isnt getting a signal cuz of bad wiring, then maybe that's it?

electric fans/ac inop

Reply #17 –
I have never had Turbo, but I am pretty good at interpreting EVTM's.
For the A/C to turn on the fan you have to have power to the A/C compressor clutch.
Is the clutch engaging? If not maybe you are low on freon.

If you run KOER (engine running) with a cold engine, you should get a code 21. the ECT sensor indicating the engine is not warmed up.
Warm up the engine and rerun the KOER. The code 21 should go away.

Did you replace the ECT sensor with two wires to it? This is the one that goes to the EEC (ECA).
There is a one wire sensor that goes to the instrument cluster. This is not the one you want.

Are you up for some volt meter trouble shooting?
The "IRCM" is on the first Electronic Engine Control page for the 2.3L Turbo and is labeled "Integrated Controller Module.

electric fans/ac inop

Reply #18 –
hell yeah I am up for some voltmeter testing. 
Just so ya know...everything's been working like a champ til I pulled this aftermarket wiring  off.  Ice cold A/C and the fans come on when hot.  I replaced the ECT, but still no good,  the one in the lower intake.

electric fans/ac inop

Reply #19 –
ECT info from the 84 Shop Manual:
50°F to 240°F Pass KOEO
180°F to 240°F Pass KOER

50°F 58.75K ohms
65°F 40.5K ohms
180°F 3.6K ohms
220°F 1.84K ohms

Code 21  Temp out of specs during self test.
Code 51  ECT shows -40° (probable is max or infininte resistance. open circuit)
Code 61  ECT shows 254° (probable is zero ohms or short circuit)

You can measure the resistance of the ECT by pulling the connector off and measuring between the ECT terminals.

When you say you ran test to see if the fan ran with the engine cold and got no code 21, I am guessing that was KOEO and not KOER. Unless it is real hot in Fla. and the engine stays above 180°
Any how with no codes 21 51 or 61 it looks like the EEC "sees" the ECT sensor ok.

When you pulled the ECT did coolant run out?
Is it possible the water jacket is gunked-up and no coolant is flowing past the ECT?

electric fans/ac inop

Reply #20 –
yep, I ran Key on Engine Off.  I just wnated to see if the fan ran, which it did.  According to NATo, that means the wring from the EEC to the fan is good.  When I pulled the ECT, coolant did come out.  I will do the elec check tomorrow.  Poker nite tonight!;)

electric fans/ac inop

Reply #21 –
Look at the IRCM in your EVTM. I believe it is page 65 where you saw the Fan Control A/C Pressure Switch. The IRCM is called "Integrated Controller Module" in my EVTM.
The EEC does not know the A/C is on until you have power to the compressor clutch.

Can you back probe the connector on the IRCM without unplugging it?

The PK/LB wire to connector pin 21 from the "compressor cycling pressure switch" should have 12v with the key on and the A/C on.
You may want to check this wire to see if any "haywire" has been spliced on to it between the IRCM and the pressure switch.
Check connector pin 23 BK/Y wire for 12v. This goes to EEC pin 10 to signal the A/C is on and to the compressor clutch.
If no 12v on pin 23, check pin 22 red wire. The EEC can turn off power to the compressor clutch by putting (guessing) ground on pin 22.
You may also want to check the BK/Y wire from IRCM pin 23 to the compressor clutch to see if any non-stock wires are spliced to it.

The Fan Control A/C Pressure Switch. Not sure where it is or when it comes into play. Its' name implies it is in the A/C plumbing somewhere. If it closes the secondary fan will run if the key is on even if the A/C switch is off.

electric fans/ac inop

Reply #22 –
Did you ever do what Tom said? I would first of all disconnect the A/C clutch coil and see if the fuse blows. You could have a shorted one. It happens.

electric fans/ac inop

Reply #23 –
Quote from: TOM Renzo;364029
Remove the connector from the AC clutch and replace the fuse and turn on the AC. If it blows again do the same with the blower circuit unless the heater works ok with the fan. Process of elimination is the key to electrical problems. Check all the components controlled by the fuse that blows. I have found many AC clutch coils draw way to much current and blow fuses. Good luck

 
actually, its better to just borrow a circuit breaker fuse while troubleshooting various problems, less frustrating and the cb resets itself upon cooling down.

electric fans/ac inop

Reply #24 –
The fuse is good now.  Dont know what happened there, I may have had a wire touching ground or something.....we called that FM(freakin magic.)
I am off to try out softtouch's idea.

electric fans/ac inop

Reply #25 –
Here is what I have:
W/ the engine running I checked the circuit twice, once with max ac on and once with regular ac selected. 
The pk/blk wire has 12v to it.
The blk/yellow wire does not have 12v
The red wire has 12v
I cant see any splices on these wires.

electric fans/ac inop

Reply #26 –
Quote from: lakenheath24;364301

The pk/blk wire has 12v to it.

This is good.
Quote
The blk/yellow wire does not have 12v

Not good. We have to get 12v here for it to work.
Quote
The red wire has 12v

I am thinking 12v here should not be blocking the 12v getting through the "solid state A/C clutch solenoid control.
This wire goes to EEC pin 54 which on 5.0 and 3.8 engines provides the ground to pick the WOT A/C cutout relay.
I suspect the fuse blowing episode may have zapped the solid state circuit in the IRCM.

1. Unplug and leave unplugged the compressor clutch.
2. Start it up with the A/C on.
3. Put your test light between the positive battery post and IRCM pin 23 BK/Y wire.
4. If you have a light this may be the fuse blowing problem. Stop here I'll come up with a different plan.
5. IF NO LIGHT, jumper 12v to pin 23 BK/Y wire.
6. The fan should run.
7. If the fan runs, remove the 12v jumper from pin 23 BK/Y wire.
8. Jumper ground to pin 22 RED wire to see if that makes the fan run.

electric fans/ac inop

Reply #27 –
W/ the engine running I checked the circuit twice, once with max ac on and once with regular ac selected.
The pk/blk wire has 12v to it.
The blk/yellow wire does not have 12v

The PK/BLK better have battery its for the FUEL PUMP Pin 5 !!! Not the circuit you are having an issue with.

The BLK/Yellow is for the compressor clutch.
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

electric fans/ac inop

Reply #28 –
Ok here goes it

Fuse 17 feeds one side of the Cycling clutch switch. The battery comes from the panel control switch in the dash to the cycling clutch switch. The other side goes to pin 21 of the IRCM. The AC clutch gets its battery and ground from the IRCM. Ground from pin 16 and or 15 which are common. The battery comes from pin 23 of the IRCM. Pin 23 is interrupted by the ECM commanding it to do so with a WOT signal  from PIN 54 of the ECM to pin 22 of the IRCM. So you shot that trouble correctly and the fuse held.

So when you were blowing fuses the first thing you should have dun was disconnect the plug from the CYCLING SWITCH and see if the fuse blew. Which you did. If it did not your next step should have been to disconnect the IRCM  If the fuse did not blow your next step should have been the ac Compressor clutch which you did.  But now that its work  all bets are OFF

I would bet the diode was touching ground somewhere. Just a guess

The high pressure ac switch turns on the secondary fan. The sensor closes at a set pressure. The primary fan is controlled by the CTS. If you unplug the CTS the fan runs. Or if the vehicle reaches i THINK 223* the ecm commands on both fans. Well good luck and i hope it HOLDS

So if it acts up again we will start from scratch. Cant fix something that is working GOOD LUCK
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

electric fans/ac inop

Reply #29 –
Quote from: softtouch;364257

The PK/LB wire to connector pin 21 from the "compressor cycling pressure switch" should have 12v with the key on and the A/C on.

Hopefully he checked the correct wire and just posted the wrong color code in his reply.

He will let us know.