Thermo Conversion Underway... (a little long) - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

6pAc|30nG|00n · 12-21-2003, 23:40

Well today a bit the bullet and finally got started on the conversion.

Some background. A couple of weeks ago Tibbo came round for a brew and we were checking out our cars and he was all like "shit dude havent u done thermos yet" and I'm all like "umm, no". To wich Tibbo replies "No worries I'll hook you up with some fans". So one to I return home from work to find two shrouds with 4 fans (1 complete shroud and 3 fans). So me hooks up two fans to the complete shroud and give em a whirl and success only one fan has a crack which was later discovered and was replaced and retested.

So today I bit the bullet a bit and cheated somewhat and bought a davies craig thermoswitch kit and installed this in a most discrete place possible between the airbox bottom and the headlight assembly. All wiring points and adjustable part of the switch is all within easy access.

I then went to remove the fan and shroud only to realise that I didnt have a big enough spanner to remove the poxy clutch fan lol

. At this point I just moved onto wiring parts of the loom and figuring out where I need to join cables to etc. Basically all that needs doing is to buy 3 relays (spst i think) and wire it all up, oh and get me a big man spanner.

Rollin did you say that you should tap into the blue wire going to the A/C?
Also does anyone know where to get more of these little wire taps called Scotchlocks by 3m? they are cool.

9psi EB · 12-22-2003, 00:22

Yeah, the thermo fan conversion is good if done properly,
but using scotch locks is not "properly" :)

The scotch locks have to be the most unreliable way to connect stuff,
Take the time to solder all connections and with thermo fans, dont use fuses, but use fusible links. Pay the extra for them and take the time, and it will save you a motor in the long run. Also ensure all relays are capable of 40 amps, most bosch ones are 30's.

Depending on how your switch works, if it switches the + side, then you can use a diode in series with the a/c wire, if the switch switches the earth, then you will need a seperate relay.

I have controllers that piggy back off the temp gauge sender and also have an additional input for the A/C. They are electronic, and therefore very accurate and you dont need to have dodgey probes in the top hose or drill and tap the thermo housing. (but you already have yours installed....)

6pAc|30nG|00n · 12-22-2003, 00:48

mmm i wasnt sure on the scotchlocks but looked handy if the workable area was tiny. For the relays I was looking at some ones from jaycar that were 30 amp but could handle periods of 40 amps. I have the wiring diagrams for a setup that will use both when the thermoswitch is activated and 1 fan when the A/C is engaged and it suggests 3 relays so I assume it switches positive.

Dang that controller you have sounds mighty good did you make them or are they a similer unit to the davies craig jobs coz there was an electronic switch and mechanical unit available.

9psi EB · 12-22-2003, 01:18

I make up the controllers, i havent seen the davies craig electronic ones, but they are probably similar.

When the A/C is on, run both fans.
I initially had problems running only one - the a/c compressor would lock up, because the condenser was too hot and the compressor couldnt push any more pressure,
(thats basically why my controllers have only one output which controls both fans, either by temp or a/c - its not worth overheating things, It can cost you a lot of money if the condensor splits or you overheat the engine)

6pAc|30nG|00n · 12-22-2003, 02:57

I was planning on making them both come on at temp and have just the 1 for the air con. Do you think that would be sufficiant or do you think I should make both come for both A/C and Temp.

Rollin · 12-22-2003, 03:05

first thing - scotch locks are EVIL ok?

second thing - the colour of the wire you need to tap into depends on where you are mounting your relays - if its right near the AC compressor, then its the blue one that goes straight to it.

if you are going to stuff them under the coolant tank like i have, the wire is green with a yellow trace - check out my website (link in sig) i have a pic up there that is a shot of my engine bay with some arrows and writing and stuff that should/might help you with your wiring.

also check THIS THREAD for more info if you like.

9psi EB - your ac compressor should not have locked - ac systems have a high and a low pressure switch (on the I6 its located just before/is part of the TX valve, which is up near the firewall on the passenger side) maybe it was defective?

i only have my passenger side fan on when ac is on, and i have a two stage temp switch. first stage is drivers side fan (to try and remove hot air around extractors from engine bay) and the second stage is for both fans to come on.

obviously, if i have the ac on and the temp gets up a little bit (like, the 'O' in normal) the other fan comes on too.

never had an ac compressor problem...

6pAc|30nG|00n · 12-22-2003, 04:18

Quote:

Originally Posted by Rollin

first thing - scotch locks are EVIL ok?

Roger that Captain, if two ppl reakon they are bodge I shall avoid them alltogether.

The relays shall be monted near the airbox so I will go straight into the blue A/C wire me thinks.

9psi EB · 12-22-2003, 04:19

Quote:

9psi EB - your ac compressor should not have locked - ac systems have a high and a low pressure switch (on the I6 its located just before/is part of the TX valve, which is up near the firewall on the passenger side) maybe it was defective?

Yeah, quite possible, but it goes to prove that it can happen....
The compressor was fine for 3-5 mins then it would just slowly get tighter and tighter and lock up, causing the clutch to slip (the mag clutch on the comp) This only happened when stationary though.
It was getting that hot that you couldnt keep your hand on the condenser.
The local air-con man that we go to said its a common fault with thermo fans not working correctly - so it must happen on the odd occasion for him to pinpoint the issue immediately (i initially overlooked this and thought it was just my comp. on the way out)

Personally, if it were my car (well, it was) or a mates car, I would wire it up so both fans come on together. Also this protects against fan, or fusible link, or relay failure.
Ensure you run one fusible link per fan, 1.0mm fusible link, and around 10 -15 cm is sufficient. I originally had blade fuses for each fan, but these had a tendency to melt quite consistently. (they were initially 30A each, then I also tried 2x20A parallel per fan)

The fans on my car only ever come on when stopped in traffic, 50 + km/h and the cooling is sufficient without fans, but its entirely up to you.
Me personally, I like to do things once, and know its not going to fail or cause problems later on, but people can have their own opinions - its entirely up to you on how you want yours to run.

My fans come on between the O and R on the gauge (EBII)

6pAc|30nG|00n · 12-22-2003, 04:42

Thanks for the input guys, 9psi EB where did you get your fusable links from, did you just source them from Ford or somewhere, Jaycar doesnt seem to stock any, I was planning on using some chunky inline fuses 30 or 40 amp one for each fan.

9psi EB · 12-22-2003, 05:44

I got mine from Marlows at the time, but most places like repco, auto one etc have them available, just ask around, if at worst, any auto elect can help you.

Give the fuses a miss, seriously,
They run way too hot with a constant 20+ amp running through them, like i said, i melted heaps of blade ones, glass ones are not much better, cause the actualy fuse material will get hot and expand, and flex, then it gets weaker everytime it heats up / cools down until it fails.