joni 0 Posted July 24, 2008 (edited) I've recently added an extra fan (in the spare section of the fan housing) to cool down my 205. I simply soldered the new fans wires into the original fans wiring and kept my fingers crossed. Both fans kick in when they need to but turn at a much slower speed and therefore don't appear to be cooling the water temperature quickly enough. Can i simpy get rid of the resistor (it seemed pretty damn hot maybe i am overpowering it? but may be cos its mounted on the rad) or change it for one that allows more current through? Please can some one help i have a rally this sat eve and i'm only online today/this eve. Sorry if this reads like amateur electronics - unfortunately i've got no excuses, it is!! Edited July 24, 2008 by joni Share this post Link to post Share on other sites
Anthony 1,003 Posted July 24, 2008 Remove the resistor and join the two wires together will give you full speed fans when before you had the slow speed. My preferred way of doing twin fan conversions is to use the relay setup from 205 diesels (twin fan as standard), as you're putting alot of current through the thermoswitch otherwise, and they're not exactly reliable as it is. That said, I've never yet found a situation where you need twin fans on a 205, unless it's masking another problem on the cooling system - if the rest of the system is in good condition, a single fan should easily keep the temperature under control IMO. Share this post Link to post Share on other sites
joni 0 Posted July 24, 2008 Remove the resistor and join the two wires together will give you full speed fans when before you had the slow speed. My preferred way of doing twin fan conversions is to use the relay setup from 205 diesels (twin fan as standard), as you're putting alot of current through the thermoswitch otherwise, and they're not exactly reliable as it is. That said, I've never yet found a situation where you need twin fans on a 205, unless it's masking another problem on the cooling system - if the rest of the system is in good condition, a single fan should easily keep the temperature under control IMO. Cheers Anthony - will remove the resistor. And relay it if i have time on Saturday. As for cooling problems, i blast around in 1st and 2nd gear to the limiter in summer weather on some rallies. Would rather have overkill than have to slow down (like last year). Have renewed waterpump, cooling system is clean/clear and has plenty of coolant. Radiator is not new but flows very well..... did i mention that i have two 10'' spot lights in front of the grill?!!! Want to make sure the fuse/relay are right. Any ideas how much current the fans will take without the resistor? Share this post Link to post Share on other sites
Rob Thomson 6 Posted July 24, 2008 Radiator is not new but flows very well..... How a rad 'flows' is irrelevent because you can't tell what it's internal condition is like. I used to road rally my 309 GTi. Big spots, lots of 1st/2nd gear nadgery twirling all night long. It used to get quite hot, so I changed the thermostat, tried it without the lights (made no difference), flushed it... Nothing worked so I fitted another fan (connected via a relay to a switch on the dash) but that didn't really help either. Eventually I fitted a new rad and it made such a vast improvement I removed the 2nd fan as even the standard fan almost never kicked in. Can't you have a look in the main fuse/distribution box behind the NSF headlamp to see what the existing fuse is? Share this post Link to post Share on other sites
joni 0 Posted July 24, 2008 How a rad 'flows' is irrelevent because you can't tell what it's internal condition is like. I used to road rally my 309 GTi. Big spots, lots of 1st/2nd gear nadgery twirling all night long. It used to get quite hot, so I changed the thermostat, tried it without the lights (made no difference), flushed it... Nothing worked so I fitted another fan (connected via a relay to a switch on the dash) but that didn't really help either. Eventually I fitted a new rad and it made such a vast improvement I removed the 2nd fan as even the standard fan almost never kicked in. Can't you have a look in the main fuse/distribution box behind the NSF headlamp to see what the existing fuse is? Fair enough Rob. maybe i need a new rad. As for the fuse can do that too. Will see if i can get a rad before Saturday night. Are you still rallying nowadays? The rally is going around Cullompton area so not a million miles from you. Share this post Link to post Share on other sites
Para 82 2 Cars Posted July 26, 2008 After my last twin fan conversion i've connected fans in the wrong way and i was driving for ages with the fans working different direction Share this post Link to post Share on other sites
joni 0 Posted July 28, 2008 After my last twin fan conversion i've connected fans in the wrong way and i was driving for ages with the fans working different direction Managed to wire up the second fan using a relay to the battery. spins up really well and was definitely needed on saturday night. Might change the rad soon to be safe. This has got me thinking..... have i wired up the relay the right way so that the fan works as intended!!! it does cool at the moment but if its pulling air the wrong way round it could be better!!! Share this post Link to post Share on other sites
Simes 248 2 Cars Posted July 29, 2008 That said, I've never yet found a situation where you need twin fans on a 205, unless it's masking another problem on the cooling system - if the rest of the system is in good condition, a single fan should easily keep the temperature under control IMO. Same here, there's no point. If one fan cools it down leave it alone - it should never overheat. Share this post Link to post Share on other sites
Para 82 2 Cars Posted July 29, 2008 Places for two fans were maid only for special countries where it's really warm and car is more able to overheat. UK is mild all the time so there is no need for second cooling fan. ps. Still it makes deadly noises when you are standing in the traffic and 2 fans are working ;D Share this post Link to post Share on other sites
cRaig 273 1 Cars Posted July 29, 2008 Cars with air conditioning also came with the twin fan setup to cool the condensor I still havent quite figured out the wiring for them. Apparently the 2nd fan should be on a very low speed all the time, and then speed up when the AC is turned on.. Share this post Link to post Share on other sites
petert 601 Posted July 29, 2008 (edited) The twin fan setup is dead simple, for 205 Jetronic or, Motronic 205/Mi16. On low speed, the fans are connected in series. On high speed, the fans are connected in parallel. Let me know if you need a wiring diagram for either. Normally off. When A/C compressor is turned on the fans go to low speed. High speed only comes on when the engine is very hot! Edited July 29, 2008 by petert Share this post Link to post Share on other sites
joni 0 Posted August 4, 2008 Decided to buy an ali nissens rad. hopefully that should cure my problems but will keep the twin fan setup as a back up for the time being. Share this post Link to post Share on other sites
