Depends which boards you're looking at - There's a bunch of RS owners clubs (Biggest being the RSOC, as far as I understand it), but this particular discussion only comes up when someone's broken one. Generally I'd expect most of the chatter to be on Facebook groups these days, but most of my talk about it has been on the Mk1FocusRSOC forums, I think in the members only section. Most people just seem to lament that theirs is broken, buy a replacement, and complain about Ford not making them anymore. I know a few guys have tried other relays, but they never work as far as I know - Which is ridiculous. It's a relay that powers a fan on based on a temperature reading - It shouldn't be as complicated as it is.
Hmm, yes that's interesting. I think perhaps you have the measure of it though, if it does fail investigate it at a component level, as others have said it's likely to have a diode or capacitor that fails which should be replaceable without too much effort?
Not meaning to disparage other RS owners, they're often quite good at things in their own right, a lot of them seem to be rather.. Unwilling to take something like a relay apart and work out what's gone wrong. Given the cars are 18-19 years old, this relay appears to only feature on the RS, and the average life cycle of capacitors appears to be measured in tens of thousands of hours, I'm thinking those are the most likely points of failure. The one I took pictures of was first popped open by me - And it was spotless inside, so I'm guessing heat is more likely than corrosion or something caused by the elements. I guess electrical shorts could have blown resistors, but those should also be pretty easy to spot. Ultimately though it's all speculation until I get my hands on a dead one.
Out of interest what does the relay do? Seems like a very complicated setup compared to the usual functions.
This: I'm guessing the complexity is related to hysteresis - making sure the fan doesn't keep rapidly switching on and off as the temperature fluctuates around the trigger point. I'd be tempted to replace it with a microcontroller-based alternative, except I dunno if being inside an engine next to constant explosions would do an ATtiny8 much good...
It's listed as the coolant fan relay - And removing it, that's the only thing that stops working as far as I know. I've tried to get more information about why it's different to the standard coolant fan relay - But that's not likely to turn up anything of use, the Ford documents for things nearly twenty years old are archived as far as I understand, and need authorisation to access. Yeah, I don't know what being under the bonnet might be like for a microcontroller - I dare say a more dedicated mind might be able to piggyback the ECU pins for the coolant fan and make a microcontroller that sat inside the car and just used a regular relay with the existing wiring, but that person isn't me.
Thanks, sorry hadn't read the thread properly I wonder if the answer to why it's so complicated is because they shoehorned an air-water intercooler into the car, the passive temperature controlled units usually fitted to cars of this age have hysteresis built in to stop mad on/off behaviour, but perhaps it isn't nuanced enough when you've got a heavily loaded and charge-influencing cooling loop. There's a pdf wiring diagram here: http://navody.ford-focus.cz/Ford_Focus_manualy/mk1/FF1_el_schema.pdf Page 96 for the RS cooling control, 95 for the AC-equipped ST170 before it, totally different.
Yeah, that PDF does the rounds on the forums - And has a permanent residence in my 'car stuff' folder! It's possible - But the chargecooler loop is entirely separate with no temperature sensor in sight. It's possible that the electronics were designed with it in mind and it was never added, of course. The chargecooler just runs if there's ignition switched 12v - I actually used that as a pickup for ignition switched 12v for my DRL's.
The chargecooler pump will always be running, what I mean is that the fan control won't just be based on the coolant temperature, but the intake charge temperatures as well. Even if the coolant isn't at the usual boiling temp for heat rejection, you'll find the PCM triggers the fan on low/high to reduce charge temps, after all the PCM is controlling both stages. Even so, it seems like a complicated setup, it'd be interesting to find out why.
Ahh. I can't say for sure - But I don't think there's anything like that built into the cooling system. At least, I don't think I've ever seen anyone talk about the function of the fans in that way.. That said, I know the IAT sensor is in the throttle elbow, so it's possible that is a factor.
I think the very fact they've gone to all the effort of building a unique relay for this particular model shows it must be related. It'd be interesting to see the ST relay from an AC-equipped model to compare it internally as well. Anyway, to go back to your original thoughts, I'd try and find someone who has a broken one, then it can be de-soldered and the board layout mapped. Once done you can recreate it in a simpler form (if there is one) to retrofit. Which number of the relays in the box is this btw?
On paper it would make sense that it does something else - But I know that a lot of things that should do something really don't in this car. Ultimately, the budget for things that wanted to be done ran out before they got done and compromises were made, so it's entirely plausible (to me at least) that this is just an artefact of design being squashed into a budget. Off the top of my head - R3 in the engine bay box, which on other models also involved heated front screen if memory serves. I am trying to get my hands on a dead one, but at this rate, no clues as to whether that might pan out. The only one I can find with a communicating owner is in Scotland, and it's likely coming by way of the Netherlands, so it's all a little up in the air at the moment.
I think ultimately if you wanted to know if it really did anything, you'd have to log the water and charge temps and the two pins from the PCM on a hot day to find out what the strat was, including doing daft things like heat-soak at idle then a full-bore start.
Reproing PCBs is quite an oft-done thing in the arcade community - if you find yourself in possession of a dead relay @liratheal, let me know - I could put you in touch with some people who repro PCBs quite a lot.
All things I shan't be able to do! My head is on a bench, the manifold is on another bench, and the sump and most of the sundries are on yet another bench! Noted! I'm hoping that the dead one warrants a few things removing so I can get a proper butchers at the board. That said, I think there's only one trace I'm not totally sure about.
Neither! Removing the engine, looking at an EV conversion. Really, to put it back together, I'd want to put new pistons in (One has seen better days), the block and the head probably want a skim (Feeler gauge says some low spots on the block), the head definitely needs a clean, as do the valves.. "While I'm there" I'd probably also look at the oil cooler situation, and the pump situation, adding sensors where I can.. Needs a new clutch, rear main seal has been leaking forever and a month of Sunday's so seems churlish not to expect a new clutch, turbo would probably want a rebuild, actuator definitely wants a rebuild.. Oh, and needs a new exhaust for the TÜV because the Miltek (I think) it has is not TÜV approved.. Probably wants a new fuel pump.. New ECU, piggybacked so I could maintain the alarm/immobiliser setup. The list is never ending Ultimately I'd be looking at a good portion of 64kw of Tesla batteries and a Mach-E GT motor in cost, and since EV's are the future (And I'm not hot on the 4 cylinder noise anyway) it seemed a more amusing project to convert to EV and maybe convert it to rear wheel drive. Or all wheel drive if I can get my sticky mitts on two Mach-E GT motors.. OT: I got word that the weirdness of the relay here is likely PWM. Apparently Jag used a similar, if not the same, system on the S-Type, so a replacement might be viable off a Jag parts shelf.
How would that work given that everything needs TuV approval before it even looks at a vehicle over there?
Challenging, is how it'd work. However. So long as the components have TÜV approval, and you get the thumbs up from your TÜV inspector (You can arrange meetings with them to discuss how they want to see the work done, and if you follow their guidance I'm given to understand you're golden). There are, however, places that sell approved parts within Germany, so it's not impossible, just more challenging than somewhere with lax inspection requirements.
liratheal hand builds a car from scratch, completely unrecognisable from the original, it fails TÜV approval for having a non-standard relay.
