NICO switcher ecu Question - Cooling Fan Control

[jamesmost]

I have a switcher ecu installed , Robert put like 8 programs on it.BTY i only use Mad Max and Vallet.In order to get all the programs I had to use an ecu form a 90-93Question is this:How does the 90-93 ECU control the Electric cooling fan differently then the 94-96??

[qship96]

Good question, as the 94-96 used a 2 speed fan controlled thru ECU.

The 90-93 had a single speed fan, not sure what controlled it,the ECU or other temp sensors attached to engine?

So many here claim any ECU from 90-95 is interchangable, but I remain sceptical due to this issue.

[maxnix]

I thought ECU controlled the fan. Question is, is the one speed low or high?

[jamesmost]

I thought ECU controlled the fan. Question is, is the one speed low or high?

it is ECU controlled and wes and robert know the answer.is there a way i could hot wire the fan w/ an over ride switch that i can manually control ??James

[JedCoop]

I have the same setup in my '94... NICO ECU from a '92 with TCS. This was discussed at some length at that time.

I have never had any problem with this that I know of (though my radiator did just fail last night :-( )

What makes you think you need this? Are you in a hot climate or with huge traffic jams?I ask since I thought it wasn't an issue back then, at least for me in coastal California without much traffic, but then again. We thought that the fan was really only an improvement if you were idle for long periods of time, which I generally am not. My radiator failed while driving, not while stopped, and my 6 month old thermostat seemed to work perfectly well at keeping the temp steady. So I'd like to know why you are concerned, or is this just preventative worry?

[qship96]

Condenser fan operates even during short idle time in warm weather with A/C on.The fan is triggered by temperature and a/c system pressures in the 94-96 models, with 2 different speeds used depending on operating conditions.

I can tell you that on my 96Q, with fresh fan clutch/blade,new waterpump/thermostat/radiator/ac compressor that the condenser fan kicks on in warm weather at idle with ac on within 30 seconds of idleing-so it is imparative to be sure it is working correctly as the ECU calls for it to operate quite frequently even with a completely brand new cooling system.

[JedCoop]

That can explain why my a/c doesn't get working at full cooling until the car gets moving. And it would matter more on a '94='96 because of the less efficient freon type used. Thanks.

[jamesmost]

mines not turning on i sit in nyc traffic every day on the commuteand my thermastat riuses just below trouble w/ a/c on when not moving.Wes said if i disconnect the coolant temp sensor the fan should go onwhere is the sensor ????????????????????where is the relay to tap in a switch ??????????????????????James

[qsiguy]

The cooling fan will turn on, I don't notice any different speeds. I have a '94 with a '93 ECU. Fan works even with the A/C off if the engine gets hot in mine. I checked it a few days ago when it was a 110*+ day and I was curious. I had a couple days where my temp gauge would go above 1/2, which is the normal spot. Fan was on, turns out my coolant level was just a little bit low from when I did the plenum job and didn't get it completely filled up. Check your coolant level and "burp" it to make sure it's full. Check the overflow level as well.

I know there are cooling fan issues with the older ECU's in newer Q's but it doesn't seem to be a problem in my car and I don't think any of you live in a hotter climate than Phoenix!

[JedCoop]

m... my thermastat riuses just below trouble w/ a/c on when not moving.

James

Maybe something else is wrong... like the thermostat isn't opening fully, or the radiator is clogged?

Last time I saw my temp wander from the right place, either below or above, I replaced my thermostat. Temp should stay dead steady (except under WOT.)

Mine didn't get to rise near badness before I replaced it, etc.

[maxnix]

Don't believe the in dash temperature gauge as it is heavily damped.

Get an adapter and one of the consult programs for an accurate read out.

[jamesmost]

coolant temp sensor location ?cooling fan relay ??thanksJames

[jamesmost]

coolant temp sensor location ?cooling fan relay ??thanksJames

per my conversation with a Jedi Q master i located the condensor fan relay (labeled cond fan) jumped pin 3-5 and fan has engaged.coolant temp sensor under the plastic cladding on front top of motor has not been accessed yet.........................................

[twoeightythreez]

AFAIK the '95 and '96 had two CT senders, in addition to the one wire sender for the gauge.
The '94 had only one so maybe the 94 had one in the radiator and maybe that's why yours works with the earlier ecu. I will look at mine to see....94 was a changeover year after all, and Nissan is notorious for changing wiring harnesses mid year ( ask me how I know...grrr)