So I've had a series of issues with my 99 4cyl LX. It was leaking coolant so i ended up taking out and replacing all the hoses. Now the fans don't appear to be coming on and my card is throwing a code. I can't check the code until tomorrow when my goof brother returns my obd but i'm guessing it's related to the sensor or wiring. I checked the continuity which is fine and i checked the voltmeter and it looks like it's throwing 12v. could that be a problem? i thought the wire should only be carrying about 5v to the temp sensor?

 

you are likely checking one of the fan switches not the engine coolant temperature sensor as it appears you are trying to test

 

well, there are two cables, one plugs directly into the distributor and the other goes into a sensor that is downstream from the lower radiator hose. isn't that it?

 

ok, so after thinking about your post i went out and checked the fan cables themselves and i'm not getting any voltage. i am however getting continuity. what the heck?
i did put in a new distributor and i put in a short-ram intake. that shouldn't matter right? car seems to be driving ok, all other electronics ok. car thermostat reading at least made sense,
but fans definitely not coming on. while running or with the key in position 2.

i guess i really need to know what the error code is but i don't understand where the problem could be.
maybe i damaged something when i was messing the heater core hose? should i be able to manually move that plastic switch?

 

So the error code is P1381

from autocodes.com:
-Faulty Cylinder Position Sensor
-Cylinder Position Sensor harness is open or shorted
- Cylinder Position Sensor circuit poor electrical connection

and its the damdest thing but the rad fans come on when i turn on the AC fan... the LEDs are flashing at me. Could this all be due to a need to change out the temp controller in the cabin?

 

WATER PUMP - SENSOR for 1999 Honda ACCORD SEDAN

Start the car and then gently crack open part number 12 in that diagram about a quarter turn, it will quickly squirt out air and then coolant. When it lets all air out and only coolant comes out, quickly close it.

See if the fans turn on before it starts trying to overheat. Keep in mind the fans will only come on when the car gets to a certain temp. It may not be getting to that point thus far for you which you may think there is a problem when it's not really acting up yet.

 

cool. i will give that a try. do you think that air in the system could be causing that code? i did bleed it when i refilled. i think i need a new climate control panel.

 

Is your car actually overheating or are you just assuming the worst?

You can look inside the distributor and see if there is dust from a failing distributor bearing. Its possible the distibutor just needs to be replaced to fix that code.

Neither issue is related.

 

I'm not sure. But i can tell you it was one of the hotter days on record here in central NC on Saturday and the rad fans never came on, after a drive, or letting it sit idle for 10-15.
What does happen is they only come on when i turn the ac fan on. what on earth? i believe you that the issues aren't related, but they could both be symptoms of the same problem?

 

Idle the car and sit inside and wait for the fans to come on. If it starts to try to overheat shut it off and report back.

Its normal for the fans to turn on when the compressor cycles on.

You may be imagining things so just check it out. Report back.

 

did that, fans only come on when ac fan is turned on. 100% sure

 

also it stalled out at idle a couple times

 

Turn the ignition to on without starting the car. Unplug the connector for the fan switch(where lower radiator hose meets the thermostat assembly) and stick a paperclip in the connector and see if the fans come on.

 

it's the damnedest thing. in position 2 (ignition off) If the AC fan is on, the radiator fans are on. If the AC fan is off, the radiator fans are off.
If I bypass the ECT by shorting the circuit with a paperclip as you suggested the fans come on with the AC off.

 

The problem is part number 15 in this diagram. Buy it directly from Honda. You will need to gently crack open part 12 when you fill the radiator and close it when no more air comes out. Then continue filling the radiator til full.
WATER PUMP - SENSOR for 1999 Honda ACCORD SEDAN

 

isn't that the ECT sensor?

 

No.

 

i guess i'm confused - if shorting the ECT causes the fans come on, doesn't that mean the ECT is the problem?

 

I already told you that that isn't the ect.

 

like i said, I'm confused. I understand the part in your diagram isn't the ECT sensor. Are you telling me the part I paperclipped isn't the ECT because respectfully no, you didn't tell me that or I misunderstood.

 

 

WATER PUMP - SENSOR for 1999 Honda ACCORD SEDAN

ECT = Engine Coolant Temperature Sensor is for the ecu

which is part 17 here

Engine Coolant Sender is for the gauge

which is part 14 here

 

I see. So i was calling it the wrong part. Sorry- i misunderstood. the part i paperclipped plugs into the thermo switch. the ECT sensor looks like it's under the distributor. thank you for your continued support - i will get that part and report back!