Cooling fan problem

Rob,

It's hard to say without seeing the truck exactly where and how the previous owner rigged it. The best thing I could recommennd is to follow the rigged wires or check near the fan to see whether or not the original wires were cut, tapped into or just disconnected. From there you can put it back the way it was before and proceed with diagnostics. It could be that the fan motor has failed and is drawing too much amperage. If this kept blowing fuses he might have straight wired it with a switch which would explain why the switch is now overheating and is a fire hazard. Also could be just a cheap switch.

Once you get it back together rule out:

Faulty/missing fuses

Faulty fan

Faulty relay

Faulty temp sensor

There are other things that could have failed but we need a good starting point so we can try and narrow this down. Post back with what you find and we can go from there. Thanks.

Rob,

The switch doesn't belong there in the first place. Secondly if for some asshole reason you're gonna add a switch you gotta switch it through at least a 40 amp relay.

What's the problem?
Is the car running hot or overheating?

Rob,

The relay should be in the power distribution box near the battery. Also, there is a fan control module mounted on the right radiator support towards the top engine side.

Ford cooling fan controllers late 1980s and early 1990s Mustangs and other models.

The controller contains a fan primary relay, A/C fan control relay, and wide open throttle cutout all built into one unit. The controller is supposed to switch on both fans when the compressor clutch is engaged. The problem is the two fan motors pull so much amperage that they rob voltage from the clutch. Consequently, the compressor clutch may only get 9.8 volts instead of full battery voltage causing it to slip, overheat and fail. The cure here is to add a separate relay for the compressor clutch so the clutch can draw full voltage from the battery.

Ford integrated relay control module (IRCM) introduced in 1986.

This unit controls the both fan relays, compressor clutch relay and the fuel pump relay. The module is mounted on the radiator shroud and is exposed to a lot of heat so failures are common. One symptom here of a failed module is a car that cranks but won't start because the fuel pump isn't getting any power through its relay. A failed module may also prevent one or both fans from operating, or the compressor clutch from engaging. The IRCM module also provides two-speed (high and low) fan operation by using an internal resistor to drop voltage to the fans. This resistor often burns up and fails. If any of the subsystems inside the IRCM module have failed, the whole module must be replaced.

BIG BLOCK
THANKS FOR THAT INFO THAT MIGHT ALSO EXPLAIN WHY THE CAR IS HARD TO START AFTER IT STALLED ON ME AND WAS HARD TO START [HAD TO HOLD PEDDLE TO FLOOR]ONCE AGAIN THANKS GOT SO MANY CRAZY WHAT IFS I DIDNT KNOW WHERE TO BEGIN

THANKS ROB

Rob,

The first things to do is to get rid of switch, put all the wiring back to original, then check for blown fuses, blown circuit breakers, and blown fusible links. From there the most common failure with the system is the failure of the integrated relay control module (IRCM). This is supported by your last answer, where you state you have trouble starting the car. The simplest thing to do is to get another IRCM from a junkyard and try it. A good professional yard will guarantee it's parts, so even it it doesn't work you can get your money back.

BIG BLOCK,
REPLACED IRCM & COOLING FAN BUT THE FAN STILL DOESNT WORK WHAT TO DO NOW THANKS FOR YOUR TIME & KNOWLEDGE
THANKS ROB

Hello Mr Bateman,

With regards to your last thread have you made sure the fan itself hasn't failed? This is simple to do and can be done with any constant 12 volt power source in your T-bird. Simply jump the fan to any constant directly powered 12 volt source (battery for example) and if the fan does not energize immediately, then you know the fan itself is defective.

Thank You
Helene

Rob,

I'd like to get back to basics and go maybe one or two steps at a time.

Do you have battery + voltage at both of the black and orange wires going to the IRCM (two wires both black with orange stripes)?

Do you have a good ground at the black wire going to the IRCM?

HELENE
I tested the fan & it works fine

THANKS ROB

Rob,

I agree with Drivability that you gotta make sure you have voltage and ground goin to the IRCM. Also check the connections at the IRCM. Make sure they are on tight and that they are clean. Another thing to think about is the IRCM itself. You said you replaced it. Well, where did the replacement come from? was it used? did it come from a junkyard? The point is maybe the replacement is bad.

tested the IRCM GOT GOOD READS ACTUALLY GOT 3 IRCM 2 FROM JUNKYARD 1 OFFLINE WHAT ABOUT THE TEMP SENDING UNIT? going to check & replace it I'LL LET YOU KNOW
IF THAT WORKS
THANKS FOR YOUR HELP
ROB

Rob,

I know you mention that you tested the IRCM. Does that mean you not only checked for power and ground but also checked to see if you're getting signals from the computer?

Rob,

Don't just change the temperature sensor like that. Check it first. If you need help with how to check then let us know.

What's the color and condition of the antifreeze?
When was the cooling system last flushed?
When was the thermostat last replaced?

Has the car ever overheated or ran hotter than normal?

In terms of checkin the IRCM circuit drivability is right. It's not enough to have a circuit (power and ground) at the IRCM. You gotta make sure the IRCM is gettin the signal from the PCM when commanded.

Ignore the MIL (aka check engine light) do a scan for error codes even if the light is off. If there are post them so we can see them. (

Hi everyone this is Rob's wife Diane,thanks for all the help this is becoming a pain but good news Rob replaced the temp sensor(Big Block, he did this before he received your response)well what do you know all 3 of the IRCM work lol.But as soon as we put it back into the spot it belongs and tightened it down it stops,I tried all 3 and happens each time. ???? Any suggestions now?? Thank each of you guys in advance for any help you can offer us.

Oh geez just read the comments,Drivability - How do you check if the IRCM is receiving the signals from the computer? Big Block - Rob said the antifreeze is green and clean, he just flushed the system and since we just recently bought the car I don't know when the thermostat was last replaced. Again thank you for all your help. Diane

Bob,

I have some input on this. For my input to be (CONSTRUCTIVE) and before the cart is put (MILES IN FRONT) of the horse here, has the switch been eliminated? Has the cars wiring been restored back to OEM configuration? Is the wiring (TO THE) IRCM in good condition and in working order, and are (ALL) connections on tight and clean?

Rob & Diane,

You stated that three IRCMs funtion until you secure them to the vehicle so it only makes sense (unless you have three bad IRCMs????) that you have either a connection/wire going open or a wire opening or shorting when you move the harness/IRCM.

I'm in hopes that the wiring diagram I have is correct as far as wire color and configuration is concerned. I'd like you to check the wires below TWICE. Check them once when the IRCM is loose but the fans are operating. Check them again when the IRCM is secured and the failure occurs. I'm trying to figure out whether your problem is from the harness to the harness side of the connector or if the problem is from the harness connector to the IRCM.

Here are some wire colors. Please tell us:

Do the colors appear to be correct?

What readings do you get when using a DVOM?

Check the wires at the connector itself with the IRCM connected. Again, please check them twice as mentioned above. Tell us what changes when the failure occurs. PLEASE USE A GROUND SOURCE THAT HAS BEEN CONFIRMED!

2 black/orange wires

1 yellow wire

1 red/light green wire

1 black wire

1 tan/orange wire

1 pink wire

2 brown/yellow wires

2 brown/ orange wires

Again, let us know if the wire colors match what you have. Over the years the harness could have been altered. Another possible problem is that this diagram is incorrect. I have had pretty good luck with the info from this database but would prefer an original paper manual. The problem is that I don't have the 20 + year old paper Ford manuals for a super coupe in any of my pockets. :-( Maybe other contributors to this site will see this and be able to check the wire colors they have.

Let us know what you find. Thanks.

Hello Mr. Batman,

I hope this helps.

http://jrthecar.com/articles/ircm/theory.html

Thank You
Helene

Rob,

You can install all the IRCM modules you want, but if the relays inside the modules are bad, then it's no different than installin a defective module. Here's another link. It tells you how to open up the IRCM and put it back together. Use this link along with the link that Helene posted to "Check all" the relays.

http://jrthecar.com/articles/ircm/assem.html

ok here goes took ircm apart relays tested fine im beginning to think its the cars main computer since i cant cant get the ARC & the fog lights to work whatdo you guys think any connection with the 3 not working

thanks rob

Rob and Diane,

Previously you stated "all 3 of the IRCM work lol.But as soon as we put it back into the spot it belongs and tightened it down it stops,I tried all 3 and happens each time. ????"

Is this still the case?

Did you check the wiring as mentioned above?

Did the wire colors match?

What are the readings?

Rob and Diane,

Doesn't add up that 3 IRCM's would work when connected but stop workin when tightened down. You gotta look into that and fix it. That's most likely is the problem. You gotta find why that's happening. Wouldn't be the cars ECM causin that, so I don't understand why you lookin to replace it. For what it's worth, here's a link that shows what it looks like.

http://www.ebay.com/itm/1990-Ford-thunderbird-ECU-Engine-Computer-OEM-T4-?cmd=ViewItem&item=190523347869&vxp=mtr

drivability with the ircm when i reconnected the plug &didnt tighten the screw i could wiggle it just a bit to one side & fan would come on if i tightend the screw i couldnt get it to come on all wiring is in great shape no loose or frayed wires

big block the web address on ebay was taken down

thanks rob

Rob and Diane,

Sounds like your really warm. I agree with Big Block 100%. Don't worry about the ECM. I intentionally didn't give you the ECM description or location. I wasn't trying to hold out on you (OK, MAYBE A LITTLE)but based on what Diane already stated (10/17/11 at 8:25) your problem is at or near the IRCM. Based on your last description, I personally would clean and tighten the terminal connections (you have male and female terminals it needs to be a tight fit) and use a little dielectric grease when you go back together with it. If that doesn't do the trick you should really consider checking the readings (as mentioned above 10/17/11 at 17:29) to see which circuit is giving you up. From there you can narrow it down.

well i got the fan to work went back & cleaned tightend
& tested everything & it works NOW ANOTHER PROBLEM THE CAR NOW WONT START UNLESS I HOLD PEDDLE TO THE FLOOR & ONCE IT STARTS IT IDLES @ 1800 - 2000 RPM I CAN DRIVE IT BUT ONCE I SHUT IT OFF IT TAKES 20 - 30 TRIES BEFORE IT WILL START ALSO THE FIRM RIDE LIGHT BLINKS 3TIMES STOPS THEN 3 TIMES WHILE KEY IS IN THE ON POSITION [CAR IS NOT RUNNING]ANY IDEAS BEFORE I GET A MATCH & END THIS CARS LIFE

THANKS ROB

FBI,

Please ignore this posting and/or take me off of the watch list since it is only a joke.

Rob,

ANY IDEAS BEFORE I GET A MATCH & END THIS CARS LIFE

Yes but before I get to those, I just wanted to say that couple bags of ammonium nitrate and some diesel fuel seems to yield the most satisfying results. :-)
WE'VE ALL BEEN THERE MAN! Back to basics.

You'll probably want to see what the vehicle is lacking (fuel, spark, etc.) when it won't start but BEFORE you do this I recommend you run a KOEO (key on engine off) and a KOER (key on engine running) test.

The link below is for the KOEO. You can use a test light if you don't have a meter.

http://www.troublecodes.net/Ford/

This link is for the KOER:

http://fordfuelinjection.com/?p=94

Once you have performed these tests, post any codes back here. After you have performed them you can check for vacuum leaks, fuel or spark delivery issues etc. We can guide you through those tests as well as pinpoint testing computer components if needed.

The links below should be helpful on the ride light issue.

http://www.albeedigital.com/supercoupe/articles/firm-ride.html

http://www.fordforums.com/f35/firm-ride-trouble-code-170496/

Good luck and let us know what you find or if you have any questions. I'm also curious if these problems have been occuring for a while or if they just started and if they started at the same time. Thanks.

Rob and Diane,

Glad to hear you got the fan working. In addition to what Drivability posted about fuel and spark basics, I just wanna remind you that the fuel pump RELAYS are inside the IRCM. If they are defective that could be the reason for the hard start problem you are now facing.

thanks guys i will do the test on sat. morning the problems just started. after the car sits for about 1hr
it fires right up no peddle to the floor however i did notice that when i tried to start it after it ran i got a strong odor of gas & black smoke out of exhaust
[unburned fuel?]the car is not my daily driver just a project ran fine last wknd put about 300 miles on it
then i went to the store about 12 miles yesterday & when i came out it wouldnt start when it did the high idle kicked in

thanks Rob

Rob,

After you perform the KOEO & KOER, when you check the fuel pressure, volume, and delivery, you might want to look for a couple of different things. Check that the pressure is not only high enough but also that it is not too high. Also, when you turn the car back off, you might want to let us know what the pressure does (monitor for a drop in pressure). You mentioned that it is hard to start and having to sometimes hit the gas to get it to do so. You also mentioned it smokes black after start up and that is unburned fuel (as you mentioned). If your pressure is too high or you have a leaking injector(s) or a combination of the two, it could be flooding causing the hard start and the black smoke that follows. Fuel pressure should be approximately 30-40 psi (depending on vacuum). Also, check the vacuum line to the regulator to see that it is not wet with fuel.

just started. after the car sits for about 1hr

i got a strong odor of gas & black smoke out of exhaust

then i went to the store about 12 miles yesterday & when i came out it wouldn't start

Rob,

The above are your statements. They speak for themselves. Do you know what a fuel leak down issue is (secondary to a loss of residual fuel line pressure) and how to test for it?

the codes that came up w/car running 23 that code also came up w/key on engine off & 53 again both. The fuel pressure @ IDLE 38PSI OFF 40PSI BIG block no i dont know what that is or how to test it
thanks ROB

Rob,

OK! HERE WE GO! SORRY BUT YOU DID ASK!

A residual fuel pressure test checks to see if pressure drops after the pump is shut off.

A fuel pressure leak down test checks to see why.

As Big Block mentioned, the leak down test is "secondary" and is only needed if the vehicle fails the residual test.

As it stands right now, we don't know about the residual pressure. Above, I mentioned monitoring the pressure after the fuel pump is off. Until that info is known, we have no reason to go further with that test.

PLEASE PUT THAT OUT OF YOUR MIND FOR A NOW! I WILL COVER THAT AT THE END!

What we do have, is a problem confirmed by the computer. You mentioned the codes.

Codes 23 and 53 both involve the TPS (throttle position sensor). They are indicating that the computer appears to be getting a high voltage reading from the TPS. The TPS is used to tell the computer where you are on the gas pedal. The more the throttle is opened, the higher the voltage. The higher the voltage, the more fuel it adds.

You have three wires going to your TPS (located on the side of the throttle body, after the air inlet hose):

Black and White = ground

Orange and White = power

Dark Green and Light Green = sensor output

PLEASE TELL US IF YOUR WIRE COLORS DIFFER!

You should use a lab scope (more accurate) but you can use a DVOM (digital volt ohm meter) to check the TPS.

Before the test you should make sure that the throttle plate is closed.

1 Connect your meter to a (confirmed good) ground.

2 Turn the key on.

3 Check the BK/W wire to see that it has .05 (YES .05) volts or less. Record your reading.

4 Check the O/W wire for a 5 volt reference. Record your reading.

5 Check the DG/LG wire (throttle closed.) Record your reading.

6 Still attached to the DG/LG wire, slowly open the throttle. The voltage should slowly and gradually increase (watch closely for drops in voltage during this sweep). Record the WOT (wide open throttle) reading and make note of any drops in voltage during the sweep.

7 Repeat step 6 but this time use the handle of a small screwdriver to TAP LIGHTLY on the TPS during the sweep. Again make note of any drops.

PLEASE POST THE RESULTS OF STEPS 3,4, 5, 6 AND 7! WE CAN GO FROM THERE.

AS FAR AS THE FUEL PRESSURE TESTS ARE CONCERNED:

The link below shows you a fuel pressure test. It starts about 1/4 of the way down the page. It's not for a Thunderbird SC but it is very similar.

http://www.explorerforum.com/forums/showthread.php?t=221335

I want to make a correction to the test. Even though it appears to be something like Ford's test, it is WRONG!

Assuming you pass A1, it takes you to A10. If you pass A10 it takes you to A11 and passing that takes you to A12. Everything is good up until that point. If you fail A12, it tells you to replace the pump. :-( NO! NO! NO! That is not the next step in any rational fuel injection system diagnostic! You will even see this to be the case if you look at A13. If you fail that test it says to replace the pump and if that doesn't work you should look at the injectors. Closer but still no cigar. I bet they sell alot of pumps though. :-)

The test should be performed with adapters on the fuel lines (inlet and return) which allow you to open and block the flow (I will explain towards the end). If it fails A12 you should try the test again but this time ALSO blocking the inlet line while simultaneously killing the power to the pump. Then, you should monitor for a drop in pressure. With both of the lines blocked, you should have NO DROP. If you do, it is either leaking externally (including into the vacuum line of the regulator) or it is leaking down through the injectors.

Explanation of the adapters:

When you restrict fuel lines, it is never (despite what some manuals will tell you) a good idea to pinch them off. Lines made of rubber, nylon, neoprene, etc. can permanently collapse causing a restriction. Even worse, this could cause damage to the structural integrity of a line resulting in a leak. Don't get me wrong! I have cheated and I know other pros who have. I don't know your skill level and I mean no offense but when people like Big Block, ASE and myself are under a hood, we know when, where and how to cheat, as well as the possible consequences. Your car is over 21 years old, so what is mentioned above, is even more critical.

HOLY CRAP!!! Sorry about the long and drawn out post (BELIEVE ME). Let us know what you find or if you have any questions. Thanks.