Please help with my mom's car. It's a 1996 Honda Accord EX 4cy. The coolant temperature sensor in the dash does not work right. It will say the engine is cold well after the temp has heated up because the heater is hot. And when it does show warm it is well below the half way point. Is there a sensor somewhere that I can replace? Thanks!

 

have you replaced your thermostat, or are you sure its the sensor?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jwogen1 &raquo;</TD></TR><TR><TD CLASS="quote">have you replaced your thermostat, or are you sure its the sensor?</TD></TR></TABLE>

That is what was wrong with my 93. It really sucked because on raod trips the temprature would drop even after a hour of driving.

 

Everything appears to be working right. The heater gets hot and the a/c works.

 

The ecu temp sensor is under the distributor its one wire.

 

No.... The ECU temperature sensor has nothing to do with the dashboard gauge. The sender for the dashboard gauge has one wire, the ECT sensor for the ECU has a 2-wire plug. There's also a fan switch with a 2-wire plug. They don't 'share' information. Different years Honda moved those things around a bit, but in my '95 Integra & '98 Accord, the gauge sender & the ECT sensor are both on the head, near the nozzle for the upper radiator hose.

 

Yes, most Fuel Injected vehicles use 2 temp sensors. The 2 wire one is for the computer. That one is usually in the thermostat housing, or in the coolant stream. The one for the guage has one wire, and is usually screwed into the block itself.

Here is an easy way to test the guage to find out if you have a bad guage or a bad sensor. When you find the sensor, pull the wire off of it. Leave it hanging in the air. Turn the car on, the guage should read cold. Turn the car off, and ground out the wire to the block. Don't worry, you will not fry anything doing this. Turn the car on. The guage should now read full hot. The sensor works on electrical resistance. The hotter the sensor the less resistance, and thus your guage moves.

Good luck to you.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jrs_03_accord &raquo;</TD></TR><TR><TD CLASS="quote">.... Don't worry, you will not fry anything doing this...</TD></TR></TABLE>Yes you will... when you ground it out. But OK when you leave it disconnected.

That's how you test the gauge, but both my Helm manuals say DON'T let it get all the way to the top. Watch for the temperature gauge to climb towards HOT. But you have to REMOVE that wire from ground BEFORE it gets all the way up.

 

if it moves at all then it is the thermostat

 

OK, so ground it out, get in the car, and before it gets a chance to go all the way up, turn the car off?


And if the guage moves all the way, the sensor is OK, and then maybe the thermostat is bad?

And if the guage moves the same amount when I test it, then it's the sensor?


Right now the guage moves, but not very much.

 

When you ground the wire & watch the gauge, you're checking to make sure the gauge works.

You can test the sensor itself by measuring its resistance at a couple different temperatures. Look 'em up in a repair manual. Maybe someone with a '96 can post the correct values? (I don't know if they're different for different years.) The 'proper' way to do it is put the sensor in a pot of hot water along with a thermometer.

If BOTH the gauge & the sensor check out OK, then you can suspect the thermostat. A bad thermostat causes the true temperature to act funny. A bad guage or bad sensor just make a bad measurement; when the actual temperature is OK.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JimBlake &raquo;</TD></TR><TR><TD CLASS="quote">Yes you will... when you ground it out. But OK when you leave it disconnected.

That's how you test the gauge, but both my Helm manuals say DON'T let it get all the way to the top. Watch for the temperature gauge to climb towards HOT. But you have to REMOVE that wire from ground BEFORE it gets all the way up.
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I am assuming this will prevent damage to the guage. The wiring won't be fried, and niether will the sensor.

Adam F123 , I hope you get this fixed soon.