what's the other sensor?

I got some good advice here about changing the water temperature sensor
on my 89 Accord Lxi. While I was changing it, I broke the wire on the
sensor right next to it, the one with the green connector. I was
wondering what this sensor does, because it doesn't seem to have
affected anything when the wire broke.

 

one is the sensor for the ecu, the other is the sender for the gauge.
the ecu will run the engine without a sensor, but it'll be /way/ rich
when warm. you should be able to see if the gauge is not working.
either way, suggest fixing soonest. cut a replacement connector + some
wire from a junk yard, then use crimp connectors to fix this to your
existing wires.

[use crimps not solder. solder fatigues, cracks and fails in a high
vibration application like this.]

 

That's funny. It looked like the gauge was working. But maybe it just
hangs around the middle when it's not connected.

I'll go and get a connector tomorrow.

 

Unlikely. The other sensor is for the fan timer unit, a very essential sensor.

This is highly unlikely. Solder joints are one of the most reliable.
The service manual even instructs how to solder correctly inside
the engine bay.

 

I was figuring I would solder it back together. I solder a lot on other
projects. I was just curious what the sensor was for, because if
nothing changed then maybe that means that it was no good. But if it
runs the fan I probably wouldn't notice it being disconnected because I
was driving on the highway.

Anyway, I'll fix it today and the car will be working great now. Thanks
again for everybody's help. You guys are terrific.

 

again, you'll not see any solder joints on honda cabling, and that's for
a reason. you won't see it on any aerospace apps either. /always/ use
crimps in any application that is subect to vibration for the reasons
stated before.

there's a 3rd sensor [switch] for the fan. that's lower on the list of
priorities.

 

I'll go to the junkyard and see what they have. Depending on how much
wire I have to work with I'll come up with a good way to put it
together. I have crimps, solder, heat shrink, tape, whatever.

 

is the OP the poster with the cold start prob? or was it a warm start
prob? if its burning gobs of fuel when warm, that could be a problem.

 

I was the guy with the cold start problem and the transmission that
stayed in first when stone cold.

I replaced the water temp sensor as suggested and all running and
starting problems have disappeared. Now I have to fix the wire on the
other sensor, because apparently it has something to do with the fan.

 

I strongly advocate crimping over soldering which lacks none of the
disadvantages of soldering except when the proper tools and connectors
are not used.

But to say that solder fatigues, cracks and fails in a high vibration, is
inaccurate. Soldering creates a single failure point by turning multistranded
wire into a single strand at the solder joint. If you solder the wire you stiffen
it at the point where it meets the solder.

The REAL proper way to solder wire is outline in a simple drawing the service
manual. Novices shouldn't attempt wire soldering without this info.

You will also note various solder joints are employed in shock and vibration
environments. A few examples are inside the alternator and starter solenoid.
The alternator has eight rectifiers with 16 solder joints expose to road salts
oils, ozones, you name it. The alternator has two flexible copper braids
soldered and tethered to the brushes which are constantly exposed to
vibrations, if not flexes. The solenoid has two joints soldered to a copper thin
lead exposed to serious shocks. These parts can last up to 350k miles
or more and rebuilt consecutively.

I strongly disagree as an advocate for reliability in the automotive field for the
past many years. I have encountered many head failure resulting from the
neglect of the third sensor. The failure rate on these head were extremely high
on vehicles that didn't equip them based on the current 2.2-liter aluminum
head designs. Again, this is one of the most essential silent killer.