johnnyboy

Thanks for you reply. I have emailed them today. Cheers John They got back to me to say the fans are single speed (not two speed as Stock).. They explain that the "Direct plug-n-play for 2003-2006 Nissan 350Z Includes factory plugs for easy installation" refers to the shroud using the same mountings as stock and the fact that the plugs fit. The fact that they operate differently (and cross connect the 4 pins in the plug to "correct" the wiring) notwithstanding. No comment made on my "both fans or none" issue (though unless they have caused a relay to play up I can't see that this is their fault) Not happy.

I was quite happy with them until I heard the noise and then found out they were single speed. Then not so much If you decide to get any can I have your old ones?.

Exactly... Particularly bad when you are going slow with the aircon on on a warm, damp, day - in fact today! (Noisy fans when you are desperate to cool the thing down on a hot day at 5000 revs is OK. On tickover round town is less so.) Also, I am finding that the engine keeps getting too cold! The fans are so effective that they drop the radiator below "normal" operating temperature and cycle off...

Could it have been the flat battery triggering some sort of "limp home mode"? Which might clear if you run it for a few minutes? I was impressed by the clever (?) way the engine management reacts to overheating (ie. I am told it retards the ignition by more and more until it basically wont run, then when it cools it has to "learn" that everything is all right and it initially runs terribly until it has had a couple of minutes to figure it out and re-advance the ignition)

Do you mean with Nissan fans or with Mishimoto? (with a scanner and the Nissan fans installed, I am sure I saw it cycle through the "modes" as described above - it was just that the LH fan would stick sometimes until you gave it a tap)

Too Late! (The old ones were binned ). It all seemed so simple... Nissan wanted £560 for a new fan (ie. each, and I think not including VAT). I did think of trying to refurb the old ones but didn't find the link you have.... and I saw elsewhere on here that people were giving good reports of Mishimoto replacements. At £171 for a pair (with shroud), it seemed a no-brainer. I should have known better. But thanks anyway - I should maybe get some Nissan fans (and a shroud...) from a breaker and give it a go...

Hi Guys. Anybody know why the engine management system on my 2006 350z has started asking for both cooling fans to come on full ("mode 3"), whatever the input? Until recently the RH fan came on slow ("mode 1") with the aircon switch, the LH fan came on slow ("mode 2") when the engine got up to temperature and they both came on full ("mode 3") when the coolant temperature got over 100 degrees C. To confuse the issue I have just put some Mishimoto fans on, and I understand (from Mishimoto support) that although Mishimoto fans are now "plug and play" and require no wiring changes they are only single speed fans (I was not amused at this definition of "OEM compatible"...). However, they say there is no reason for the fans to have caused this "both or nothing" scenario (anybody out there with Mishimoto fans got any ideas?). I have taken it to a "Nissan High Performance Centre" who billed me £87 for plugging in a scanner and telling me that the fans were doing exactly what the controller was telling them to do and that there were no fault codes, and suggesting that I paid them a further £240 to check the wiring (but agreed that they could not think of any possible wiring fault that would cause this scenario....). Any thoughts on a next step?

Somewhere within 50 miles would be great...

I have had someone suggest that it is a "failsafe feature" and that if there is something wrong somewhere the management system "fails safe" by turning both fans on full to make sure nothing overheats. (which sounds possible...) Someone else has suggested it may be one of the three relays in the "IPDM" that has failed ("independant power distribution manager" - I looked it up... ). Which also sounds possible and should be an easy fix. Snag is they are £35 each and Nissan parts want to know which one I want... and it is still a bit of a coincidence that it failed just as I changed the fans... I took it to Colliers Nissan High Performance Centre in Yardley yesterday for a "diagnostic". They had it for three hours, charged me £86.70 and said that they did not know what it was and that I needed to book it in for a full day (additional £240) for "extensive wiring checks to the air conditioning wiring system". (which doesn't sound logical to me...) Help!

Thanks for you reply. I have emailed them today. Cheers John

Hi. You are right - with just aircon the right hand fan (looking from the drivers seat) should come on slow, on its own. But of course if the engine is warm the left hand fan should have come on slow on its own as well (so to speak). The third choice (when the engine is HOT, whether aircon on or not...) is both on full. But, mine don't seem to understand this any more, and just both come on full ("mode 3" according to the scanner) when either engine is warm or aircon on... so if anybody knows what I need to do to fix this I would be most pleased.... John

The latest Mishimoto fan shrouds now come with the correct plus for plug and play fitment We have them in stock if required. I just installed a pair of new Mishimoto fans and shroud, but they only come on as a pair, not singly (ie. when I turn on the A/c or the engine gets up to temperature) have I ended up with some old stock?

Hi. It appears s that I may need one of the above. Anybody got one for sale? Or do I need to go to a dealer (£££!!!).

Hi. Thanks for you help. I thought Mishimoto had sorted this wiring out since the posts you mention. After all, they advertise "Direct plug-n-play for 2003-2006 Nissan 350Z" and "Includes factory plugs for easy installation" which is a bit rich if they are only single speed and you have to cut, splice and solder the loom to make them work! Also, their plugs have all 4 pins connected (two blue and two black, though they are spliced into two to go into the motors) which I thought indicated 2 speed.... otherwise they might as well have just connected pins one and three to get the same effect.... And finally, surely they would have mentioned this somewhere in their fitting instructions!! Another also, I thought that the fact that when I turn the AC on, BOTH fans come on, when they are plugged separately into the main 350z loom (and not connected to each other at all) would mean that the controller must be (wrongly) telling them both to come on? It is a bit suspicious that the controller failed just at the moment I changed the fans, but.... If so, where IS the "controller"? Is it the IPDM behind the battery? Can i fix it? Do I need to get one from Nissan (£££!!) or a scrapyard / ebay? Cheers

Hi Guys. Just had a similar problem with the fans on my 2006 350z (LH fan stopped working at all, RH fan only went slow...) so as per above thread I bought/installed a pair of Mishimoto fans and shroud. Job done. except.... They both come on full or not at all.... If I start the engine (cold...) they are off. If I turn on the AC both fans come on full (and stay on.... if I turn it off they both go off...) When the rad gets warm (with AC off...) both fans come on full. Then both go off as it cycles etc. So no single fan independent running and no slow speed running. I just plugged the in. Should I have told the ECU about them or something? It has certainly solved any overheating issues, but you can hear them over the engine / radio.... Help? John