Hello Everyone!


I'm having some troubles with my 94 Honda Accord DX. As soon as I put the key into the ignition and turn it to ACC mode, the temperature gauge on the left of my spedometer immediately spikes to its highest point.

I've tried unplugging sensors to see if they would reset the gauge with no luck.

How would I even begin to diagnose this? I've tried googling it without any luck.

 

The temperature gauge is controlled by the sending unit (located under the distributor area). There is a Yel/Grn wire that is plugged into the sending unit that runs to the gauge. (Yel/Grn wire is a wire with yellow colored insulation and a green stripe running through it.)

If it is spiking to Hot right away when you turn on the ignition to ON, even when the engine is cold, then:

1. Unplug the Yel/Grn wire from the sending unit. There may be a short in this wire, such as being caused by wire insulation melted or nicked and the bare wire touching chassis/body ground. This will cause the gauge to move up right away. -- Check for a short in the wire.

2. If you can't find a short in the Yel/Grn wire, then you can do other tests, such as a resistance test of the gauge sending unit. Unplug the Yel/Grn wire from the sending unit. Measure the resistance of the sending unit between the positive terminal of the sending unit (tip of the sending unit) and engine ground. When it is cold should be about 137 ohms. If the engine is at operating temperature, it should be about 30-46 ohms.

3. If there isn't a short in the wire, then it can be a faulty gauge or short at the gauge.

 

Thank you for your quick response!!!

Here are a couple of images that I took, which one is the sending unit?

http://imgur.com/a/9P2tc

Actually, is it this one? The single wire one?

http://honda-tech.com/attachments/ac...ff-car-269.jpg

This is not my vehicle but I have the same setup.

 

Wrong connector. The one in your second photo, photo B that one you did not disconnect is the ETCU connector. Hope this helps and welcome to the HAF site.

 

You mean this one?

https://i.imgur.com/kfanuYE.png


Also, I found this photo online (my car has the same setup). They are calling it the sending unit (the single wire one):

http://imgur.com/CIiJ3eY

 

See attached.

 

My first reply already had a photo. See post #2 of this thread.

 

Ah ok! Sorry, it was difficult for me to make out what that first photo was in post #2.

Unfortunately I'm not able to find a short in that wire. I will have to go buy a ohm meter (I don't have one handy) to check it.

Is it possible that the actual sending unit is bad?

 

Issue can be either:

• Wiring
• Sending unit
• gauge

Short can be at wiring or gauge.

Tests help narrow the issue.

 

Ok, so I unplugged that sending unit: http://imgur.com/sWdaT6Q

As you can see, I accidentally broke it a little. I didn't know that it was a plug and I was trying to take the whole unit off with a wrench.

Then I plugged it back in. I went to start my vehicle and the temp gauge seems to be normal again. The only problem: I can't get the engine to turn over. I don't even hear the fuel pump start.

I know it's not the fuel pump itself because I replaced it a couple of weeks ago.