99 Dx: Is there a fuse for the coolant temperature gauge?

[DarkCreep]

Hey all

1999 Civic Dx 5 speed D16Y7

I have an Ex cluster and I noticed today the temperature gauge wasnt working. I looked in the fuse box and the under hood fuse box and I couldn't find any fuses for the coolant gauge.

How would I go about fixing this issue? Im selling the car in 3 days and im also doing a 1400 mi drive back to CA and I really need my temp. I do have 2 extra temp sensors (they go on the lower coolant hose housing on the block amirite?) and I could swap those in when I get a 24mm socket.

Edit:

I guess thats the ECT switch.

 

[DarkCreep]

Thermostat was replaced a year ago, and the cluster is not an issue. I swapped in the original Dx and its still doing the same thing.

 

[RonJ]

Unplug the 1-wire sending unit and ground the connector wire to the engine with the key in ON(II). Does the temp needle in the cluster rise?

 

[DarkCreep]

What exactly do you mean by ground it to the engine?

I unplugged the 1 wire harness and grounded it to the battery. I went to check and the cluster and it didnt move, stayed at below C. Do I ground it on the engine itself??

 

[RonJ]

If you ran a wire from the 1-wire plug to the battery ground post, then that's fine.

Do other gauges in the cluster work?

Do you have a multimeter?

 

[DarkCreep]

Everything else on the cluster works perfect.

What exactly is it supposed to do when I ground that wire?

 

[RonJ]

Everything else on the cluster works perfect.

What exactly is it supposed to do when I ground that wire?

If the other gauges work, then a blown fuse is ruled out.

When you ground the sending unit wire with the key in ON(II), the needle should rise toward Hot.

Do you have a multimeter?

 

[DarkCreep]

I can definitely get a multi meter. What would you like me to do with it? How much voltage must there be on that single wire?

Today I replaced the ECT Gauge Sending Unit and Engine Coolant Temperature Sensor and nothing.

 

[RonJ]

I can definitely get a multi meter. What would you like me to do with it? How much voltage must there be on that single wire?

Measure continuity of the wire from the sending unit plug to the cluster plug.

Today I replaced the ECT Gauge Sending Unit and Engine Coolant Temperature Sensor and nothing.

The ECT sensor has NOTHING to do with the temp gauge in the cluster, so that was a waste of money. Replacing the sending unit falls into the category of replacing parts at random. Rise above this newbie strategy and test before replacing parts.

 

[DarkCreep]

Ill do that tomorrow and tell you about my findings. I hope there isnt a faulty wire in this harness, its a perfect uncut harness :/

As for the replacements, I have a ton of left over sensors from swaps and rebuilds we used to do at my house in CA so I didnt pay for them.

 

[RonJ]

Ill do that tomorrow and tell you about my findings. I hope there isnt a faulty wire in this harness, its a perfect uncut harness :/

Based on your comments, it's a bad wire or bad temp gauge.

As for the replacements, I have a ton of left over sensors from swaps and rebuilds we used to do at my house in CA so I didnt pay for them.

I think you understand what I meant by saying:

Rise above this newbie strategy and test before replacing parts.

So many people on tech forums replace parts at random as their strategy to fix a problem. There is a better, more elegant way to fix cars. I'm trying to get people to learn a better strategy that is overall faster and less expensive to fix car problems.

 

[DarkCreep]

Im going to put blame on the wire. The gauge on my Dx cluster does the same thing. When the light is out tomorrow ill put a multi meter on it.


I complete understand what you are saying though, and I agree with it. My brothers '91 Dx died a year ago and we could not get it started. I bought a new distributor thinking that was it and it wasnt. You cant return distributors to auto parts stores lol, so I was assed out on $130. We ended up doing an MPFI swap and forgot about that issue. Im still curious to this day on why it didnt start since everything checked out okay.

 

[DarkCreep]

Where do I put the knob to RonJ?

 

[RonJ]

Turn the knob to measure continuity - sound symbol (see red arrow in diagram below). Now touch the two meter probes together. Do you hear the meter make noise? If so, unplug the sending unit and the cluster and then use a wire to ground the sending unit plug to the engine, body, or negative battery terminal. Now, back inside the car, touch one meter probe to the Yel/Grn wire at pin B12 in the cluster connector and the other probe to the metal frame behind the dash. Does the meter make noise again?

 

[Hecz]

 

[RonJ]

Eat too much buttered popcorn and you will become morbidly obese.

 

[DarkCreep]

Hey I grounded the sender unit wire to the chassis and the needle didnt move in the cluster.

Next I replaced the ECT switch. I am NOT saying that it fixed it, but once I did that, turned on the car and let it warm up, the needle worked. I dont know if it had anything to do with it, or maybe the wire was just loose on the sender unit and I shoved it in there.

Things look good so far. Im going to take it for a drive and see if anything changes. Just in time hopefully! Im leaving tomorrow!

 

[RonJ]

...or maybe the wire was just loose on the sender unit and I shoved it in there.

This^

Things look good so far. Im going to take it for a drive and see if anything changes. Just in time hopefully! Im leaving tomorrow!

Have a safe trip.

 

[streetdemon70]

On the lines of coolant guage issues i have one. On my 00 EX when im on the throttle it stays below the C. As soon as i let off the throttle it goes to normal operating temperature. When i turn the car off it goes below the C. Any idea what this might be?

 

[RonJ]

On the lines of coolant guage issues i have one. On my 00 EX when im on the throttle it stays below the C. As soon as i let off the throttle it goes to normal operating temperature. When i turn the car off it goes below the C. Any idea what this might be?

Start by checking whether the coolant level is low in the reservoir and/or radiator. Top off if low.

Next:

Bleeding the cooling system may take 20-30 minutes.

1) Park the car on an inclined driveway with the front end higher than the rear.

2) Push/turn the dash heater lever/knob to MAX heat. Fan need not be on.

3) Follow the directions in the diagram below