What goes in this hole?

I hope I can put this drawing of the Back side of an 86 1.5L Carburated Block.
There's a place for a Thermo sensor. Right next to the Oil sending unit.
Can someone tell me which Thermo sensor (A or B) it is?
What does it do for me?
Do I need it?
Could it be for the F.I. model?

I have three of those Thermo Sensors. Two in the bottom of the Radiator, and this one in the block. I have a factory book. It does not tell me which sensor (A or B) this is, nor what the wire connections are.

I have a photo out of the book but I cant seem to get it into this post?

to post pics u have to put them in the gallery or anywhere on the net and then use the image code button in the reply section, looks like this [IMG]url[*/IMG] (remove *)
i am not entirely sure what the Thermo Sensor you are talking about does. i know that one of the ones on the rad ones controlls the fan. in my 83 i have one in the head and the block and the one on my head controlls the heat gague and i am assumeing that the one in the block does the same but i am not sure on that. as for the second on in the rad i am also not sure.

Your right CVCC, I forgot the sensors in the Head.
I think the drivers side Sensor in the Rad is for the AC.
The Passenger side is for the Fan, and the single wire sensor in the head is for the Temp guage in the dash.
The Large Sensor in the Head with two wires is another of those mysterious Thermo-sensors that may be for the Fan control relay.
I have a factory manual and it does not identify any of these sensors clearly and distinctly.
I'd like to ask the Jap Designer why he can only identify "Sensor A and B" is there are Five sensors?

yeah, my factory manual does not specify either. if u have A/C then you are quite rite about the other rad one, that would only make sence to me.

:useless:

Trav, you have such a cute way of saying I'm bathed in ignorance..
I have a photo. I got it out of the factory manual. I just dont know how to put it into the forum page.

However. I have the engine back in the car and its running.
I put a meter across the snesor I installed in that hole and when the engine warms up, the switch closes. So what I put in there works.
The engine runs hot. I jumped the radiator fan, and that keeps the engine from boiling over.
So....if I could figure out which sensor, and which controller box starts AND stops the cooling fan, I'd have that part licked.
It still wont Idle. I think I must have some of that Vacuam stuff in the wrong place.
I am quite sure, this Honda from Hell will be the last Basket case I ever take on. For the rest of my life!

what kind of idaling problems is it haveing and is it missing?...... :smokin:

Mike, I'm down to a very few problems now.
One... I cant get it to Idle properly.
Two... I cant seem to get the Fan to work on Auto-mode controlled by the sensors and whatever else is in there to turn the fan off and on.

I dont find anything like a 'fan control relay' out under the hood. Is it somewhere else?

the fan on my 86 is jumped you would have to test each water temp sensor the one on the head on the radiator ect or just dont waist time and replace them all my also may want to replace the thermostat......as for the idle it could be a few things you should see a bunch of hoses going to the carb one by one clap each one off and see if it affects the idle you may also have a bent/or sticking valve in the head is there any smoke