04ra254

ok hey guys just wanted to ask a question i just bought a 2004 RA Metallic Silver 83xxx at the end of last month. Ok so when i got the car the fans weren't running at all i did a little research in the forum and figure the Fan Control Unit needed to be replaced so ordered the part replaced it and still the fans aren't cutting on, even when turning on the a/c unit and letting the car warm up has anyone else experienced this issue any idea what it could be......btw i did search the forums and saw a similar fcu replaced and still not working thread but unfortunately it didn't seem to finish out any help would be much appreciated thanks guys

CrAnSwIcK

iTrader: (5)

if the FCM takes a poop, the fans will run all the time, if they don't come on at all it's more likely a fuse or relay...i'll edit with more details, i just need to look over the wiring schematic.

i would replace the relay... part # MR301978

it's located here:

04ra254

Thanks CrAnSwIcK I figured as much looks like im going to have to order the relay none of the mitsubishi dealerships in a 250mile radius of me have it in stock. I appreciate all the helpful info.

Raikiri

iTrader: (21)

Go to mitsubishiparts.net and order from them. Great service and most of us here have ordered from them sometime or another.

CrAnSwIcK

iTrader: (5)

if it's not the relay there's a fusible link and some other garbage, hopefully it's not a wiring issue

i was thinking maybe a stuck thermostat but even with that i would think you'd have overheating issues. it's the AC fan not coming on that makes me think it could be a relay. are you having any overheating problems?

weird that none of them have a relay in stock

2006_RA

iTrader: (1)

If you're in Texas you want these guys:
http://oemmitsubishiparts.com/

They are in Weatherford just outside of Fort Worth.

xmaster19

iTrader: (1)

Make sure you have the right fan control unit. The dealer near me didn't have the right one in stock, but had a different number but identical part on hand. Tried it on and fan did not go at all. Immediately took it off and went inside to order the right one. IIRC correctly, the wrong part number ended by a 3 and right one ended by 1. Or vice-versa.

Answer must be somewhere in there :

https://www.evolutionm.net/forums/04...estions-3.html

Too lazy to go through all the pages...

04ra254

Thanks for all the help guys i ended up ordering the relay from the stealership it wasn't to bad $21.19 just replaced and the fans are working fine. The car was overheating previously but that was because there was little to no coolant in it which i didn't notice when i bought the car about a month ago but everythings working great now, thanks again for all the help just wanted to post because i hate when an OP lets a thread die without any solution to the issue.

CrAnSwIcK

iTrader: (5)

thanks for posting back, cheers

xmaster19

iTrader: (1)

All that coolant went somewhere!!

Check your water pump for leakage. If no signs can be found, check your compression.

CrAnSwIcK

iTrader: (5)

lol...good point...should keep an eye on that...

04ra254

Ok so I've replaced the fcu and the relay the fuse is still intact and yet my fans aren't cutting on on again. So after i replaced the fcu and reconnected the battery the fans cut on and seemed to be working fine then one day as I'm driving i see the engine temp rise and the fans aren't cutting on then i got the relay installed it the fans started working again that was like 3 days ago then I'm driving around downtown San Antonio today during fiesta allot of stop and go traffic and see my engine overheating once again pulled over pooped the hood and the fans aren't cutting on again I'm getting so frustrated at this point i tried citing the ac on to see if the fans would cut on then and they didn't do I'm getting a little agitated any other ideas what could be causing it there was coolant in it this time. Any ideas would be extremely helpful. Also my car had some gauges in where the head unit was originally a vacuum volt and temp now one thing i have noticed since having purchased the car is that the temp gauge hasn't moved once since being in possession of the car could out be a thermostat issue? TIA and sorry for the long post

xmaster19

iTrader: (1)

The thermostat is too cheap to not swap it in for a brand new one just to rule this out.

Usually, aftermarket gauges have a dedicated sender they connect to. The signal wire might not even be connected. Whoever installed it might have skipped this part.

Recheck all the fuses. Test the relays with a multimeter. Inspect all the fan wiring. Test the fans.

Again, make sure you have the right FCU part #.

If all this fails, sledgehammer to the hood.

It doesn't help fixing the car but should relieve some of your stress.

CrAnSwIcK

iTrader: (5)

isn't the coolant temp sensor monitored by the ECU/FCM as part of the logic to control the fans?

the fans cut on when you reach operating temp, if they don't, it's not reaching operating temp, or something is wrong with the control circuit...the fact that you're over heating would make me think the thermostat is not opening, or the fan control is not working, on the other hand if the control circuit is good, a stuck open thermostat would likely prolong the fans coming on...

i'll ponder on this a while longer...

04ra254

So cranswick do you think it may be a faulty coolant temp sensor? Ill probably end up replacing the thermostat within a week or so I may just end up replacing the coolant temp sensor as well since the thermostat is only like 12 bucks and the coolant temp sensor is only 20 or so. I'm just getting a little agitated that i can't figure out what's going on