EL Thermo Fans - Calling all EL Owners!

Yagz · 04-04-2005, 12:00 PM

Ok,

My XR8 is an EL, and i got the fault code 778 during diagnostics, which means that the passenger side thermo fan isn't working..

Now, i've done a few tests, and it looks like no matter what we try, only the drivers side fan works at one given time..

So, what i need from you guys, is anyone with an EL to go outside, turn their A/C on at idle, and tell me whether both thermo's come on, or only one..

If you guys have both thermo's turning on, then i guess it's a relay issue, as the fuse seems to be fine (after replacing it)

Thanks,
Yagz

svo347 · 04-04-2005, 12:08 PM

The other fan comes on full time, the 2nd fan will cycle.
Sounds like a relay as you suggested.
Tried swapping the fans over to make sure it isnt knackered?

Yagz · 04-04-2005, 03:18 PM

Yeah.. we ran the fans both off a constant 12v supply, and both of them work when hooked directly upto a 12v power..

I'm going to try and replace all the relays..

04-04-2005, 04:03 PM

I have an EL 6 and both fans run at low speed together then both at high speed if the temp gets around "O" or if A/C is running flat out. From memory there are only two relays controlling the fans - I found out because one of the relays failed and all I got was one fan running flat out when the temp hit the "O" mark.

If my recollection is correct the fans are run in series for low speed and parallel for high speed. If the single fan is only running flat out then you probably have the same problem I had - you can swap the two relays over to confirm. You should only need one relay but I'd get both so you've got one spare.

They are the white ones down near the passenger side headlight. I think there are two whites and a green.

Yagz · 04-04-2005, 05:08 PM

Quote:

Originally Posted by WeirdEL

I have an EL 6 and both fans run at low speed together then both at high speed if the temp gets around "O" or if A/C is running flat out. From memory there are only two relays controlling the fans - I found out because one of the relays failed and all I got was one fan running flat out when the temp hit the "O" mark.

If my recollection is correct the fans are run in series for low speed and parallel for high speed. If the single fan is only running flat out then you probably have the same problem I had - you can swap the two relays over to confirm. You should only need one relay but I'd get both so you've got one spare.

They are the white ones down near the passenger side headlight. I think there are two whites and a green.

Yeah, i found the 2 whites and a green relays..

Which ones do i need to change? Which one controls which?

04-04-2005, 05:21 PM

Quote:

Originally Posted by Yagz

Yeah, i found the 2 whites and a green relays..

Which ones do i need to change? Which one controls which?

It's the white ones that control the fans. I think the R/H one (looking towards the car) is the high speed one and the L/H one is the low speed, but that's really streching my memory so I could be wrong. I do know it's the white ones, though, because I left them swapped over until I got a replacement.

If you replace them make sure you get the relays with the resistor across the coil because these are controlled directly by the ECU. I ended up getting a genuine Ford one because the aftermarket ones I could get hold of wouldn't physically fit.

Yagz · 04-04-2005, 05:25 PM

How much do ford charge?

So if i change the white resistors around , both fans will come on?

At the moment, only the drivers side fan works, and the passenger side one won't even bat an eyelid..

04-04-2005, 05:32 PM

Quote:

Originally Posted by Yagz

How much do ford charge?

So if i change the white resistors around , both fans will come on?

At the moment, only the drivers side fan works, and the passenger side one won't even bat an eyelid..

Sorry, don't know how much Ford charge. I ended up getting one through my local Auto 1 store about 18 months ago when I had the problem so I can't remember.

If you can wait until tonight I'll check my workshop manual when I get home and let you know.

Yagz · 04-04-2005, 05:39 PM

Quote:

Originally Posted by WeirdEL

Sorry, don't know how much Ford charge. I ended up getting one through my local Auto 1 store about 18 months ago when I had the problem so I can't remember.

If you can wait until tonight I'll check my workshop manual when I get home and let you know.

That'd be sweet, thanks

04-04-2005, 06:34 PM

OK. I've got the manual. According to the manual it looks like you've possibly got two faulty relays so swapping them over probably won't help. And I was wrong - there's three relays.

Just to confirm what speed is the drivers side fan running at and what setting on the airconditioner do you need to make it come on?

04-04-2005, 06:52 PM

I checked through the relay logic and the manual is wrong! It looks like you've got exactly the same problem I had but I need to know the answer to my questions above before I can confirm.

If you have the same fault I had you will need to switch the A/C on and set the fan speed to 3 and the driver's side fan will run flat out. If you have the A/C fan speed set to 1 or 2 then the fans won't run.

If that's the case then you can try swapping the two white relays and then you should get both fans running at low speed with the A/C fan set to 1 or 2 and only the driver's side fan running flat out when the A/C fan speed is set to 3. If that's the case then you only have one faulty relay. If not we need to do some further diagnosis.

Kenaz · 04-04-2005, 07:10 PM

Quote:

Originally Posted by Yagz

My XR8 is an EL, and i got the fault code 778 during diagnostics, which means that the passenger side thermo fan isn't working..

Off topic, but how do you perform diagnostics?

Yagz · 04-04-2005, 08:53 PM

Kenaz, a guy from fordmods came over to my house, and he had a diagnostics device, that a guy on fordforums.com was selling..

Do a search on ff.com for more info..

WeirdEL, How do i tell what speed's it's going at? It turns on once i put the fan on the A/C, not sure about what setting, but 3 sounds about right..

I will try the swapping of the relays tomorrow for sure, and get back to you

Thanks for the help!

04-04-2005, 09:19 PM

Quote:

Originally Posted by Yagz

WeirdEL, How do i tell what speed's it's going at? It turns on once i put the fan on the A/C, not sure about what setting, but 3 sounds about right..

You can tell by the noise it makes (you can hear it running from inside the car) but, if it's coming on at 3 on the A/C fan then it'll be running flat out. If you swap the relays as described above and get them running at low speed then you'll only need to replace one of the white relays. I can't remember which one it'll be but you can swap each one in turn with the new one and try it each time. Leave the green one alone for now.

Remember to turn the ignition off before swapping the relays.

Yagz · 05-04-2005, 12:01 PM

Ok.

With the relays as they are now, the thermo's only turn on at the BOOST setting, with A/C on, but will stay on when u switch to 3 from BOOST, but will turn off when 2 or 1 or 0 is selected.

So, i switched the two white relays around, and what do you think happened?

Exactly the same, no change. Only drivers side thermo turns on, and only at BOOST (or 3 if you're coming back down from BOOST) but it won't turn on from 0 until you hit BOOST.

Very confusing.. :(

EDIT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Ok, once the car gets to normal operating temperature, about on the A, both fans come one at Low speed!!! This is the only time this has happened since i swapped the relays around!!!

I don't know whether or not they click to high speed when the car's hotter, but i will go and test that right now..

Only on fan comes on at high speed with the A/C on though.. Is that right?

If the fans switch to high speed when the car's hotter, and they both work, it looks like switching the relays has made them work correctly again??

Yagz · 05-04-2005, 01:16 PM

Ok, after all the exhaustive testing has been completed, here's the final hypothesis;

Both fans will come on at low speed when the temp gets to about the A on NORMAL.

Switch the A/C on, and the passenger side fan will switch off, and the drivers side fan will come on at high speed. I took the car away from the houses, and revved it, and it took alot longer for it to reach the O in NORMAL, and once it did, the passenger side fan died again, and the drivers side came on full ball, and full speed.

So, what the hell is going on?!?!

EA2BA · 05-04-2005, 01:20 PM

maybe the temp switch for the fans is stuffed, try replace it, i guess its near the thermostat, but dont ask me what one

05-04-2005, 01:38 PM

Quote:

Originally Posted by Yagz

Ok, after all the exhaustive testing has been completed, here's the final hypothesis;

Both fans will come on at low speed when the temp gets to about the A on NORMAL.

Switch the A/C on, and the passenger side fan will switch off, and the drivers side fan will come on at high speed. I took the car away from the houses, and revved it, and it took alot longer for it to reach the O in NORMAL, and once it did, the passenger side fan died again, and the drivers side came on full ball, and full speed.

So, what the hell is going on?!?!

It's OK - just as I expected was going to happen. It means that only one of the white relays is faulty and you just need to replace it.

Get a good relay, pull out the R/H one and plug in the new one. If exactly the same thing happens (as described above) then pull out the L/H one and plug the one you pulled out into there. As soon as you have fully working fans the faulty relay is in your hand.

05-04-2005, 01:40 PM

Quote:

Originally Posted by Dellboy999

maybe the temp switch for the fans is stuffed, try replace it, i guess its near the thermostat, but dont ask me what one

Dellboy, the fan relays in the EL are controlled directly by the ECU so no temp switch.

Yagz · 05-04-2005, 02:42 PM

Quote:

Originally Posted by WeirdEL

It's OK - just as I expected was going to happen. It means that only one of the white relays is faulty and you just need to replace it.

Get a good relay, pull out the R/H one and plug in the new one. If exactly the same thing happens (as described above) then pull out the L/H one and plug the one you pulled out into there. As soon as you have fully working fans the faulty relay is in your hand.

Awesome! Dad's going to get me 2 new white relays, and i'll just replace each one.. saves messing around if it ever happenes again..

I took the car to my local auto elec, and he checked the relays, and he said one looked pretty burnt, but he just wiped away the residue, and said it should be good again, and alas, still doing the same thing..

So i've decided to bite the bullet and go ford genuine. Dad's going to get them for me this afternoon.

Thank-you so much for your help WeirdEL, Has saved me alot of time and hassle!

svo347 · 05-04-2005, 02:56 PM

Quote:

Originally Posted by WeirdEL

Dellboy, the fan relays in the EL are controlled directly by the ECU so no temp switch.

But the ecu gets its input from a temp sender, separate to the one on the dash..

05-04-2005, 02:57 PM

Quote:

Originally Posted by Yagz

Awesome! Dad's going to get me 2 new white relays, and i'll just replace each one.. saves messing around if it ever happenes again..

I took the car to my local auto elec, and he checked the relays, and he said one looked pretty burnt, but he just wiped away the residue, and said it should be good again, and alas, still doing the same thing..

So i've decided to bite the bullet and go ford genuine. Dad's going to get them for me this afternoon.

Thank-you so much for your help WeirdEL, Has saved me alot of time and hassle!

If I were you I'd keep one new relay spare and just replace the faulty one. The reason is that the faulty one was the one that was used all the time and the other one only got used when the fans were running at full speed, which usually isn't that often. If you replace both you'll be throwing away one relay that hasn't had much use. It's up to you but that's what I'd do.

Glad I could help, though.

Yagz · 05-04-2005, 02:57 PM

Quote:

Originally Posted by svo347

But the ecu gets its input from a temp sender, separate to the one on the dash..

Yeah, it's obviously sending a signal to the ECU telling it it's hot, because one fan still goes full blast, just not the other one, telling me that one of the relays isn't switching it to high speed..

05-04-2005, 03:18 PM

Quote:

Originally Posted by svo347

But the ecu gets its input from a temp sender, separate to the one on the dash..

Actually I think the dash gets the temp from the ECU. I know it gets the speed and RPM from the ECU.

The ECU knows what the A/C fan setting is and turns on both fans at high speed when the A/C fan is set to 3 or boost and this is independent of the temp so can be used for diagnostics like this.

The EL's have three relays - two white ones and a green one. The white ones are simple on/off switches and the green is a change-over. There are two outputs from the ECU - one switches one white relay on and off and the other switches the other white one and the green one. At low speed the ECU switches the white relay on and both fans are connected in series through one contact on the green relay. To activate high speed the ECU turns on the second output which activates the green relay and the other white relay connecting both fans in parallel using the change-over contacts in the green relay and the other white relay. At high speed the passenger side fan is activated through the low speed relay and the other contact on the green relay. The other white relay switches the driver's side fan on at full speed.

That's why the first white relay (the low speed one) is more likely to fail because it's in use most of the time. That's also why you get the situation where only the driver's side fan will work at high speed because low speed and passenger side high speed goes through the same relay.

svo347 · 05-04-2005, 03:29 PM

No mate there is 2 temperature senders for the EFI windsor V8
One goes to the dash gauge, The other to the ecu.
Ones connected to the heater pipe, the other is located on the inlet manifold

05-04-2005, 03:34 PM

Quote:

Originally Posted by svo347

No mate there is 2 temperature senders for the EFI windsor V8
One goes to the dash gauge, The other to the ecu.
Ones connected to the heater pipe, the other is located on the inlet manifold

: I have checked the manual and the temperature guage definitely gets its signal from the ECU - the I6 and V8 guages are the same. Don't know what the other temp sender is for - didn't look it up. I've updated my reply in case someone looks through here and gets the wrong idea.

svo347 · 05-04-2005, 03:37 PM

No dramas, what matters here is that a guy has been helped out by another member & his car is now fixed.

Yagz · 05-04-2005, 03:42 PM

It's not fixed yet! :P

When i ran the diagnostics, i also got fault code 116, which is the ECT temp sensor.. But i was told this was normal because when we did the test the car was cold..

Hope it's the relays!

05-04-2005, 03:49 PM

Quote:

Originally Posted by Yagz

Hope it's the relays!

Hey, you swapped them over and got exactly what I was expecting - it's the relay. You have exactly the same problem I had with mine which is why I know how the relays work - I had to work it out for myself. Like I said, just swap the faulty one and keep the other one as a spare.