BudWheel

I had to replace my head gasket on my d15b2 and as I was putting it together I decided to change the oil and with the intake manifold off I grabbed the oil filter and notice there's a two prong connector in the back of my block that have no clue what it is. From what I looked up it is some kind of temperature sensor that tells the fan to kick on but while my engine was running my fan and everything was working fine I have nothing connected to it I have no wires to go to it is this going to be okay? My car is a 93 delsol and this is definitely not the original engine it is out of a older 90-something Civic so of course I don't think the original one had that on the back or maybe did?

I will change the title when I get an answer hopefully soon I'm trying to get it ready for the morning and it's in the middle of the night now and I didn't want to go any further till I found out what it was and if I had to worry about it.

TomCat39

How large is this two prong part?

I suspect it is the block warmer minus the cord/plug.

On the D15B7 it's on the radiator side of the block, the D15B2 might be a little different or someone put it in the block drain plug and put the block drain plug on the radiator side.

JRCivic1

The fan switch on a '93 Del Sol is found on the thermostat housing. On the older engines, the fan switch was found on the back of the block... a large round sensor with two male bullet style connectors... just like you have described. In your case, since you have stated that your cooling fan works properly... this sensor is redundant and not necessary.

BudWheel

Thanks for the answers yall. Yeah I couldn't wait so I put it on anyways but according to yall I don't think I need to worry about it. Just wanted to know what it was and my intake was off at the time and I could get to it easily. I love my del Sol and there is a lot I need to learn. Im used to bigger V8s and such.

Since we are talking about the sensor on the back what is the one next to it? That one does have a wire going to it.

TomCat39

If it's a single wire with a big rubber boot and near the oil filter it would be the oil pressure sending unit.

mk378

Yes the two wire sensor screwed into the block above the alternator is the fan switch used in older models. In 1992 the fan switch was moved to the thermostat housing. Later D-series block castings still have a place for a hole there, in some versions a knock sensor is mounted.

Directly above the oil filter is the oil pressure sender, which has one wire. It turns the "oil" light on the dash on when there is no oil pressure.