98exowner

So I got a civic and I drove it from wisonsin to illinois 225 miles. It was fine until i got off the highway and once I got on the side streets I realized the temp guage was going really high. Got home and realized the cooling fan is not coming on. What can I check to see why its not coming on and what can I do to fix this. I know it needs a new raditor because a lot of the fins are missing on it. But I just want to be able to drive this and not have it rigged to the battery to have the fan work so I can drive it. Thanks for any advice!

redef90si

iTrader: (3)

Step 1:Buy new rad
2:flush all Rad fluid
3:changed thermostat and rad and rad cap
4:enjoy your civic

riceburnerryan

and check the radiator fan switch

B18C5-EH2

Before doing any of this you should check the fuses for the fans. It's the number 33 fuse in the under hood fuse box, and it's a 15A. There is also a main fan relay located inside the same fuse box. If standing in front of the car facing the engine bay, the relay is in the top right corner of the under hood fuse box. you can temporarily swap this relay out with another one if the fuse is good and the fan won't run even when jumping the fan switch (bolded text).

1. Make sure the radiator itself, not just the overflow bottle, has enough coolant in it

2. Crank vehicle and let it warm up - once temp guage gets to the 1/2 mark, or even slightly above it (indicating that it's going to overheat soon) take your hand and touch the upper radiator hose - it's HOT!!!

Now take your hand and feel the lower radiator hose - it should be as hot or very close to as hot as the upper hose. If it's not you need a therostat and gasket - only buy a genuine Honda t-stat and gasket set.

3. If the lower hose is as hot, and the fan(s) still don't come on then unplug the fan switch that is screwed into the thermostat housing - follow the lower radiator hose to the little metal neck it hooks to, and look for a little two wire grey plug plugged onto a brown plastic piece with a 19mm gold end that screws into the t-stat housing.

Unplug the 2 wire plug and loop a paper clip, or wire, and touch each end to the 2 pins on the grey plug you just unplugged - if the fan suddenly comes on you need to replace that gold/brown switch that is screwed into the t-stat housing.

4. If the fan still doesn't come on with the thermostat opening (lower hose is hot) AND the fan switch plug jumped with a wire/paper clip then you likely need a new fan motor itself. This assumes that the relay and fuse were already checked/swapped and are good.

All of this is assuming that you don't have a test light/multi meter to check power going to the fan motor itself.

NOTE:

I've bolded that section of text to tewll you that you can actually do this second, after checking the fuse, before even cranking the vehicle, to see if the fan motor even works at all. When you jump that switch the fan should come on, and if it doesn't then the motor is bad.

98exowner

I know the fan works because I wired it to the battery and it came on. Will try the others in the morning. That is great advice and is much appreiated!

98exowner

Ok so the lower hose is hot the jumper didnt work but I hard wired the fan and it came on. the 20 amp fuse looks good for it and I switch out the relay with one that I believe works but still a no go. If they any fuses i might be missing? Can anyone help me with this issue. Around town now it doesnt seem to start to overheat even with the fan not working its main after using vtech. My car also has a full b16 swap if that would make any difference....believe it wont

Hanmin

wiring the fan to the battery and looping the switch is 2 different things. wiring the fan to the battery proves the fan is working, looping the thingy proves whether or not you need a new fan switch or not.

xunsungheroesx

Make sure the thermostat isn't sticking open or sticking closed. Service manual has you pull it out and check with hot water.

98exowner

I looped it and it didnt mke it work but when hardwiring it, it made it come on. So that means the fan switch is good right?