younggun90

Recently the temperature gauge on my accord stopped reading anything at all, it sits at completely cold all the time. The car runs fine as normal, but what could this be? The gauge itself? The coolant temp sensor? The thermostat? Any insight or help would be greatly appreciated, because I'm not sure where to start with this one. Car is a 1993 Accord EX sedan

holmesnmanny

There are two sensors underneath the distributor. One is the two prong and one is a single prong.

Take the connector off the single prong and look at it. It might be broke. If the wiring going to the connector and the connector appear fine then the problem is probably the sensor. It's called the coolant temperature "sender". You can get these at any auto parts store. Make sure to ask for it just like that.

MAD_MIKE

If the sensor appears to be fine, or you have already replaced it, let the car fully warm up and begins to idle down. Does the gauge move at all? If it moves up slightly, or does move up to normal temp but while driving the temp begins to drop then it may be a stuck open thermostat. Part# 19301-PAA-306 from Honda ~$20.

younggun90

It doesn't move at all even when at full operating temperature. It stays below the cold mark on the thermostat all the time and doesn't move. I haven't replaced either the thermostat or temp sensor yet, just trying to nail it down between the two.

n8hoover

I am having the same problem on my 95. So i should check the one prong sensor? I pulled a 2 prong sensor at the scrap yard, but have yet to install it.

GhostAccord

The two prong is the ect sensor for the ECU. The single prong is the ECT sending unit for the gauge cluster as mentioned above. If your car drives fine and it's just your gauge that isn't reading properly it is the single pole sending unit and wiring that you need to look at testing/replacing.

n8hoover

Thanks for the help GhostAccord. I will check that out as soon as it warms up.

brakedrum

When the engine is fully warmed, if your interior heat is working like it's supposed to, you can rule out the thermostat being stuck open.

The dash gauge being stone dead due to a bad sensor isn't typical, but possible. Incorrect/erratic readings is more typical.

Another thing you can try is pulling the wire off of that sensor (the one with the single wire) and ground the wire to the engine block and watch the dash gauge when the key is turned to the on position (without starting the engine). The gauge needle should pop up to max hot position. That will confirm a working gauge and bad sensor. If the gauge still doesn't budge when properly grounded, that's either a bad dash gauge or a bad connection or ground somewhere along the wire path from the sensor to the dash gauge.

younggun90

After further inspection the outside of the temperature sensor was dirty and gunky. I removed the connector and cleaned it off, cleaned off the sensor prongs. The thermostat worked but only for around 5 minutes and was reading badly. I ordered the temp sensor, when I replace it it looks like the easiest thing to do is to disconnect the rad hose and remove the whole thermostat housing to replace the sensor.

GhostAccord

The ECT sensor and the ECT sending unit are both located in the cylinder head under the distributor. How is removing the thermostat housing going to help in replacing ether of them? Unless you are planning on replacing the thermostat while your at it. At the most you could probably disconnect the lower rad hose and moved out of the way.

The switch in the thermostat housing has nothing to do with the temp gauge. It is the cooling system temp switch A. Switch B is located on the water neck on the front of the cylinder head.

younggun90

Then what is the sensor in the thermostat housing? According to the service manual the temp sender/sensor is after the rad hose in the housing before the thermostat. If thats not it, what the heck am I looking at? And what the heck did I order?

GhostAccord

Sounds like you ordered a temperature switch. The two temperature switches are for the radiator and A/C fan control.


The single wire engine temperature sending unit for the temperature gauge is located under the distributor.

That's what everyone has been telling you from reply No.1.

younggun90

Dang, this is also under the distributor so I was confused. I purchased the temp sender/sensor

Lost Again

Warning, doing this test you need to be sure to either turn the car off or remove the wire from the ground BEFORE the gauge goes to full Hot. If you don't you risk damage to the gauge.

adamint

96 accord 4 cyl vtec m/trans

help? am trying to test my dash temp gauge by grounding the sending unit wire. I believe it is the single green/yellow wire under the distributor with the clear plastic connector on it. (I peeled back the rubber cover to expose the connector). I can't figure out how to get this connector off to expose the wire to ground it. It looks like maybe I pop one end up? don't want to break it.

also I'm trying to identify these other sensors under the distributor. is the green capped one up front the temperature switch #b and the grey-capped one behind the single wire the ect sensor? THANK YOU for any replies.

it looks like we can't insert pictures here? here's a link to the eric the car guy forum post where I'm discussing this issue if anyone is inclined to see the picture I posted.

http://ericthecarguy.com/forum/girls...ing-unit#85676

brakedrum

I looked at the picture you posted



I've never had to replace that switch, or had any reason to remove that wire, but I think the plastic piece holds the section that grips the tip on the end of the switch, so, in theory, you shouldn't have to peel away the rubberized insulation but should grip lightly with pliers and give the whole plug a slight twist to loosen it from where it has been a long time, and then pull it straight away from the switch to remove it. Then you'll need a short piece of wire to shove into that wire in order to ground the dash gauge it to the block.

Note that there is another post here about being careful to not fry the dash gauge by leaving it grounded too long. A quick check using a helper or cellphone camera is probably best.

holmesnmanny

yes just pull it off

FIY1978

there may be more than 1 ECT sensor try replacing them both. Also check your oil for water just in case there is a internal leak into the engine.if you pull the dip stick look for rainbowing on the dipstick. If there is water in with the oil it can cause over heating to the point of seizing the engine and permanent damaging of the engine in which case you have 3 options either a complete engine rebuild with new parts , engine replacement or getting a new vehicle. Hope this helps

GhostAccord

FYI197, For Your Information, I'm just being blunt here,

1. 8 year old post.....
2. There is only 1 ECT sensor for the dash gauge..
3. Water and oil in an engine makes a milkshake not a rainbow
4. This thread is about an inoperable gauge, not overheating.