My cooling fan won't kick in after i put a new radiator in i c one wire hanging on the right close to the radiator but was dark when i installed it not sure if that the problem

Did you TRANSFER the Temperature Sensor over to the new Radiator and did you Plug it in?

There is a RELAY that you may need to test or you may have an electrical problem going to the FANS? Remember you had to remove the Fans to install the Radiator but you have to Plug them in when you get done..

Hopefully you did not pinch a wire along the way...

you probably , did not bleed the radiator for proper circulation , and if you didn't notice also , you probably didn't plug your radiator cooling fan back up , because it starts up once your cars coolant becomes too hot , look into this , this could be your problem ...good luck !!

Check to see if the fans are connected to the wiring harness, if radiator was removed the shroud and fans had to be removed, are fan motors connected to wiring harness, are there any damaged wires at connectors, check the fans fuses at fuse box (Power Distribution Box) in the engine compartment (front right side)(push in on tab in front of box lift up then back to remove cover), Engine Cooling Fan Fuse, Yellow 60 amp, posistion #49, Check the Relays, Engine High Speed Cooling Fan, posistion #R8, Engine Cooling Fan, posistion #R9.

Check your coolant levels and make sure the hose between the coolant reservoir and the radiator aren't clogged. The cooling fan on the radiator may not be directly driven by the serpentine belt and may be on a clutch. If the clutch is broken the fan won't cool the radiator and the radiator won't cool the car. Get the car good and hot and see if the fan kicks on. To temporarily relieve the overheating in the engine, turn the heat on in your car.

First you should drain the antifreez by opening the drain plug located by the lower radiator hose. Then take the upper radiator hose off. Then take the 2 bolts out that hold the housing on. Remove the housng and there is your thermastat. Accordind to VW they want you to put antifreeze on the o-ring I use RTV a little extra help sealing just don't put a lot on. The book says to put thermastat in housing and turn 1/4 turn to right. I'm not sure why but thats what it says. TIP If you close the drain plug now and put as much antifreeze in as you can makes it easyer to get air pockets out later. Mount your therrmostast housing back to block and tighten bolts. Again put as much antifreeze in that you can them put upper radiator hose back on. Again put as much antifreeze in that you can. Now come the hard part sometimes getting all the air out of the cooling system. Put the radiator cap on but loose run the engine till the cooling fan kicks on but keep checking the coolant level. WARNING ANTIFREEZE WILL GET ABOVE 200 DEGREES
both upper and lower radiator hoses should be hot and radiator full. If both hoses aren't hot you have an air pocket that you have to get out. To do this run the engine a couple minutes after the fan kicks on then turn engine off for 5 or 10 minutes and start over keep doing this till both hoses get hot and the air the fan is blowing is hot. Once this is doe yout ready to go. I hose off any antifreeze that got one car so if you see antifreeze under car you know something is leaking and not what was spilled.

Che if you installed the right thermo sensor, check for broken wires and if the car has the wrong coolant sensor or the wrong thermo sensor it will not work right.

OK here we go you will need a test light for the following tests, i will try to be as descriptive as possible so lets get started

fist start the engine and turn on the a/c that should command the fan on.
right front engine compartment next to the battery is the power distribution center pop off the top, ground your test light to the negative battery terminal and find fuse number 10 it is a 40 amp fuse check both sides of this fuse with your test light, if you have power on both sides of the fuse than we shall go further.

unplug the connector from the cooling fan, there should be two wires in the plug one is dark green and the other is black with a pink tracer, with your test lite grounded to the negative battery terminal check the dark green wire for power, if there is power there than move your test light ground clamp to the battery positive terminal and test the black wire for ground,
if testing the black wire made the test light shine than the ground circuit is good, if it did not than check you ground connection behind the right headlight.
when testing the dark green wire, if the dark green wire made the test light shine and the ground circuit is good than you simply have a bad coolant fan motor.

I suspect you were not getting power to the fan motor so you will need to take a look at the radiator fan relay, this is a special solid state relay mounted to the inside of radiator core support on the right side down behind the bumper.

here you will find a single plug with 4 wires in it

black = ground
dark blue / pink = relay controll from pcm
dark green = output to radiator cooling fan
gray = battery power from fuse # 10 in pdc

unplug the relay ground your test light to the battery negative terminal, with the engine running and a/c turned on check the gray wire the test light, it should turn on if not recheck fuses.

move your test light to the battery posistive terminal and test the dark blue / pink wire, if the test light turns on than you have a bad radiator fan relay, you can pick one up at your local parts store for about $85.00 just make sure you get a high quality one the cheap ones have a hard time with the amprege consumption of that fan.

good luck

wesley [email protected]

The fans won't kick on then you need to replace the coolant temp sensor this runs your fans.

every thing that is electric needs a power and a ground if running a new wire to the fans i would prefer you to use a inline fuse this will keep the wire from catching on fire. u could run the power wire to a fuse that is ignition switch 1,2,3 one of these will work so when u turn the key they kick on. also the ground could be a bolt on the bottom of vehicle. use a test light and see if that wire hanging down is a power wire. hope this helps

1st what temperature thermostat got installed,also make sure it wasnt put in backwards,if ok start your car let it run when the temperature rise is the fans kicking on to cool the radiator,if they are as soon as they kick on ,with a rag squeeze the top radiator hose,caution it will be hot,you should lose pressure when the fans kick on in the hose it means the thermostat is opening,if ok, check bottom hose to see if you feel antifreeze running thru to let you know its circulating,if not its your waterpump,one thing you can do is when the car is cooled down take off radiator cap and squeeze bottom hose quick 4 times in a row to make sure you dont have an air pocket,if this helps please vote me a fix ya