i accidentaly posted in the member forum:

i am building a obd1 ls block. i was taking parts off this obd2 block and i notice these two plugs.. what are they and do i need them cuz im using a obd2 wireing harness.

the green plug and the one to the right of it with the two things sticking out, not the oil sender.

thanx--on my block there is a hole for the green plug, but not the other thing.

 

I thought the green one was a knock sensor of sorts. Not sure on the dual prong unit...

Jason

 

ttt

 

That green switch in a Fan Switch that activates the cooling fan. The other one i don't know what it is.

 

I beleive the green one is for the knock sensor and the other one is the oil pressure sensor. I think thats correct but check again, I haven't been under a car in a while.

 

I am only a Honda/Acura mechanic so take that for what it's worth. The green one is your ECT (tells the ECU what temperature the engine is operating at) and the two prong one is the cooling fan switch. The cooling fan switch closes when it reaches it's set temperature and turns on the cooling fans.
That is an older style cooling fan switch-the newer ones are brown and look more like your green one (ECT). If your new block does not have it , it probably came from a car that had the cooling fan switch mounted in the radiator or on the thermostat housing. The way to tell for sure if the green one is an ECT or a knock sensor is this: if the hole that it screws into has coolant in it, it's an ECT. If the hole does not go anywhere and dead ends, it's a knock sensor.

 

did he say ls block i thought ls dont have a knock sensor

 

its a '99 b18a i beleive. well its b18a thats what i know for sure. im gettin a obd2 wiring harness, could i just no hook up that plug for knock sensor.

 

that is not an obdII ls block. it should have the water temp sensor(TW) on the distributor side of the head and the thermo swtich on the thermostat housing. that block in the picture is a 90-91 ls block. that green sensor is the TW sensor and not a knock sensor. the one with the two prong is the thermo switch





[Modified by vhd, 7:23 AM 10/3/2002]

 

My thoughts exactly-sounds like somebody got hosed.

 

if its a 99 than is b18b .... b18a's were from the earlier DA chassis .... just some minor differences tho

 

Ok some of the replys here are wrong so here is the correct answer:

The green one is the oil temp switch that causes the condensor fan to come on for 15 min if the oil temp is hot enough. You dont have to use it if you cant but I would recommend it if you have a/c. If not, just ignore it or get a plug to replace is so its not there at all.

The 2 prong thing is the thermoswitch. An OBD-2 harness has a different connector and the wire is probably too shory because it orninarily would connect to a different looking thermoswitch on the thermostat housing but here on an OBD-0 block it on the back. So you can lengthen the wires and put the different connector on to use this one or ignore it and get a different thermostat housing that has the other thermoswitch.

Keep in mind THERE IS NO KNOCK SENSOR ON THIS BLOCK so dont listen to these confused people.


[Modified by erniecars, 8:39 AM 10/3/2002]

 

sorry to jack your post but since you have a pic im installing my oil pressure gauge...its for a 94 b18b...so the one closest to the filter is the oil pressure sensor rite!?!? and there should be a rubber condom on it rite with a wire inside? im trying to figure which one is the oil pressure sensor...THANKS!!!!

 

i didnt get hosed.. im just using parts off of it. i was just wondering if i should use the green connector. i guess i dont need it.

thanx everyone for your input. ill check the vin to see what year it is.

 

i have that on my b18a1 block that green sensor... since i read this post. i decided to compare my b18b and b18a1 block from the picture that was posted that b18a1 block Does ahs this green sensor.. when i looked at my b18b block it didnt have it wassup with that?

 

hah, thats what ive been asking. got some good answers

 

honest ly i dont know i thin kill put taht green sensor on my b18b block