Hey guys, I have a DA with a B2oB engine, with a p75 head. I always noticed that both of my fans would stay on when the Ignition switch was open. But, recently my radiator fan stopped working. I checked if the fan motor works, the radiator fan does run direct so I know the fan motor works. After doing some digging around on here, I discovered that the most common problem claimed by many is the Engine Coolant Temperature Switch which on a B20 engine is mounted on thermostat housing case. To my surprise, I did not even have that on the thermostat housing. There is no ECT Switch, all there is in place is a hoses which the other side leads to the head. Second, i got underneath the car to see what the back of my block looks like compared to others I have seen online. Also, I wanted to compare the side of cylinder heads as well. While, I was under the car snapping a picture of the back of my b20B block I noticed these two connector dangling but could not find where they would plug into. On Collin’s sticky another person mentioned something similar to this but no picture was available to be certain. Has anyone out there had the same experience? Or know any knowledge of the Engine Coolant Temperature Switch on B20B engine? Would i have to change over the thermo housing with one which has the ECT SWITCH and connect those two dangling connectors to the plug? Any info helpful…Thanks!
Sorry, not sure where the ECT switch is located on your B20b but it should be on the thermostat housing the ECT switch plug on your G2 will be a 2wire, yellow/green and a black and the switch was located on thre back of the b18 engine so I am guessing that one of the plugs you found was for the ECT switch. 94
I took pictures to post up but I am having trouble uploading pictures from galaxy s2. I will shoot some pictures with the canon on monday and post them up. I have gone online and seen different pics of b18 block and also b20 block. I have also read that the b20 block has the ECT on the thermostat but who ever did the swap on my car before I bought it used a b18 thermostat housing case, because it does not have it on there.
Then wouldn’t your solution be to go buy the right thermostat housing? It’s not uncommon for people to run w/o the ECT switch altogether. Honda cooling systems are quite good and in many situations you won’t even notice there’s a problem if the fans aren’t running until you get into some more extreme temps.
Yes, that would certainly be a solution to the problem. I ended up fixing the problem, blown fuse. Sometimes we overlook the simple things. Dumb, Dumb…Anyway, I still want to switch out the housing on B20 block for with the thermo housing with switch mounted, maybe that will stop the fans from running continuos while the ignition switch is on. Colin, care to chime in? This is your area of expertise…any info helpful…
Only got a couple min, but let me see if I have this straight:
- originally fan was on all the time
- then fans stopped working
- found fuse to be bad, replaced and now fans run all the time again
Assuming all of that is true, then my assumption would be that someone wired your fans to run whenever the ignition on and your ECT switch has been taking out of the picture entirely. Another problem could be that the switch is faulty and thinks the fan should always be on - however, I don’t think this is possible because IIRC the ECT switch only tells the rad fan to run, not the condenser fan (please, someone correct me if I’m wrong).
So, assuming the previous owner wired the fans to run constantly you’re going to need to re-wire everything. This may be easy, it may be hard, it depends on how they wired it up. Now it’s time to get your hands dirty and start ripping into the wiring to see what is going on.
Once you figure out the wiring you have two choices, either wire it back to stock, or wire it in a much much more simple way. Assuming you do not have A/C you can just get rid of your condenser, radiator fan control module, and ALL relays for the system. Use a multi-meter to check which wires are which. Make sure it has power, then make sure the ground for the fan is connected DIRECTLY to the ECT switch (once you get your new thermostat housing w/ switch). This wire will already be ran, you just need to move it around. I think I posted about this before, you can probably search for it. This creates a very very simple system, battery, fuse, fan, switch - DONE. No relays, no nothing. Now, before you say that’s stupid and you need a relay… this is how Canadian non-AC cars came from the factory. I’ve been running my car this way for a few years now, no problems at all (although car is NOT a daily).
This is what the back of my B20b Block looks like.
Engine Oil Temperature Switch and Engine Oil Pressure Sending Unit:
I have seen pictures online and read that B20b engines have no engine oil temp switch on back of B20b Blocks. Above is a picture of my block with both engine oil temp switch and sending unit. Does anyone know why that is? It must be specific to certain years. IDK?
This is the Two Pin, Engine Coolant Temperature Switch wiring from 91 DA Harness.
I went to the junk yard and found a thermostat cover with the ECT switch with the plug attached. I took the two wires you see in the picture above and connected them to the plug. Then, I changed over my new thermostat cover and connected into the ECT Switch on cover.
The problem now is that the fans wont turn on. My car over heats because of it. I ran them direct so they work.
I jumped the ECT Switch Connector and the fans still wont turn on. I have a problem in the wiring, either from the Fan Connector side or from the ECT Connector side. I will get the Digital Multi-Meter out and probe to see if I can pin point the problem and re-wire. I am hoping that it will just be a bad ground in the wiring. The Haynes Repair Manual has a useful schematic of the cooling system in the back for reference. For those of you who are experiencing the same problem now, here is a link that I found very useful as well.
http://techauto.awardspace.com/overheating.html#fanswitch
B20B Cylinder Head: Engine Coolant Temperature Sensor and Engine Coolant Sending Unit
I just add the picture above for someone who might want to locate this if they are not familiar with it.
Yes, I know that this is an old thread but I wanted to finish the thread. I wanted to do that by sharing the pictures and finding the solution to my problem so that just like I have searched for useful information someone else can find the solution to their problem.
Note: I used Colin’s thread/sticky as a reference.
http://forums.g2ic.com/showthread.php?196564-Engine-Coolant-amp-Oil-Temp-amp-Pressure-Swiches-Sensors-amp-Sending-Units-Explained&highlight=engine+coolant+temperature
One year later, to the day… With no update
And you still have the same concern?? Damn son.
Thanks, for pointing that out UNIFIED112. I see that no where on this post did you contribute to the Content Kitty. If you have content that you would like to contribute or share then go ahead and do so. By that, I mean other than your complaint…
[QUOTE=unified112;2298525]One year later, to the day… With no update
And you still have the same concern?? Damn son.[/QUOTE]
Yeah, man. My fans were working perfect until they decided to stop working for good. I wanted to finish the thread and provide pictures for others who will run into the same problem. I had to re-size photos in order to share them. #no trolling