KCHC

i put this under this section because its a 3rd generation retrofit, i graphed a main harness from a 94 civic coupe into my 86 hatch. so its basically all an EG civic other than the shell.
i finished putting my b16b in my 86 hatch. it is running fine and everything in the car works. except for im having problems getting my fan to turn on. and my lower radiator hose does not get hot. and it feels flacid like their is no pressure, im going to "bleed" the system next.
i jumped the switch at the thermostat housing still no fan, this lead me to believe that i have a bad fan but no, i jumped it straight from the battery and it come on right away. i checked the fuses under the dash and under the hood, they were just fine.

now to my thermostat. one thing i did was looped the heater core outlets from the Tstat-housing to the head of the engine. was i not supposed to do that? one is an outlet the other an inlet fro heater core so i dont see why that would be wrong. i didnt know what else to do and i found a couple of people on line that did that with their engines. i did it because i no longer have A/C.
that loop that i made gets hot but not the lower hose to radiator.

thanks for the help!

Ekmontreal

bleed the system first could just be air stuck somewhere your fans doesn't come on does your heat gauge go up? or is it lower than usual? could be you thermostat is stuck open

KCHC

my heat gauge goes to normal operating temperature, i let the car idle for 10 minutes and nothing happens with the fan. i'll rev it up to 3k for a while and still no fan.

KCHC

okay it seems like i got the thermostat working, i dont think it was ever not working. i think i just had allot of air in the system. my bottom hose has pressure and is warm now.

but still no luck on the fan. when i jumped the fan switch on the thermostat housing i didnt get the fan to work. so i checked for voltage on the switch by putting my + lead on the switch and my - lead on the battery ground. and i got 12.6 so i think im good. to check the relay i pulled it off the fuse box and i checked the switch again. that time i didnt get any voltage. so im guessing my relay might be good.
so far i checked fuses in both fuse boxes, sorta checked my relay, i checked the switch. and the fan.

KCHC

ttt

axis11

Deal with the fan issue first. Get a wiring diagram and trace where the fault is. Try interchanging the relays. Did you check the fuse with a multimeter or light tester or just visually? Check connectors and ground. I've seen a few of these connectors corrode and loose contact.

Ryan Lwin

Just unplug the fan and hook up the two leads of the fan to battery directly. See if the fan comes on. If not, it's dead.

KCHC

i tried that already my fan was good. thanks

Ryan Lwin

Then, check the fan relay in the under-hood fuse box (C904). Double check if you have done so. Also, try to short the fan switch above the thermostat again. If that doesn't work, trace the wire from fan switch to the fan. See if there's any problem.



This is assuming you are using the 94 fuse box as well. This is for 92-95 fuse box.

One more additional advice. Try to drive around the block. Make sure you keep an eye on temperature gauge. If it's at operating temperature the whole time, especially when you start accelerating from 0, then drive around the block. Come back, open the hood and wait for at least 10 minutes. At most 30 minutes. See if the fan comes on. If you put new thermostat, doesn't fully open as it should at specific temperature, fan won't come on but under hose will get hot still. This is because thermostat is partially open and hot coolant is passing through the bottom hose. If you drive around, then water pump will push the coolant and thermostat might open up. That will cause the fan switch to reach it's specific temperature and fan might come on. If you haven't try that, try it. I had this problem before with a malfunction thermostat before. The fan comes on but just very late. I waited for over and hour for the fan to come on at idle cold start. The heat didn't go up because coolant was partially circulating. Heat started going up after I drove for a while. Replaced OEM thermostat and everything started working as it should.

Luillo

I am having the same problem i just bought this car yesterday and I notice that the temperature gauge was not moving up at all. Replaced the thermostad and now it reach almost the middle but the fan never turns on. Any help guys. I check the fan directly from the battery and the fan will start. The ecu will throw a code if the fan switch is bad c