Sup guys, I don't know which section I should post this "topic" so please Don't get mad if i post it in the wrong section thanks.

Anyways, I just did an h2b swap into my em1 I used the em1 wire harness and pretty much just plug everything in. I kind of matched everything on my original b16 engine on th e h22a. Its very similar. Anyways, I notice my coolant fan never turns on, so if the car is on for a while, the temp creeps up. I thought it was the fan switch (the one on the thermo housing with 2 plugs, black/green wires) so I bought a new one at the dealer. Didn't work, so I tested the fan, battery and ground it, the fan turns on and worked. So I tried to test the connector. I pretty much just looped the plug bypassed to see if the fan would turn on. NO IT DIDNT. So i know its the harness problem... but it can't be, everything was good when I had a b16 in it. I thought it was because of the ECU, so I swapped ecu, to a chipped ecu, then to a p13, then to a b16a ecu. NONE would turn on when I loop and bypass. What should I do? thanks

P.S I did checked fuses and relay, they're all fine.

 

have you checked the relay?

 

Yeh I checked fuses and relay, they're all good...

 

Check the ground

 

ground? you mean the ground thats right next to the sensor that is screwed in with a 10 mm? if thats the one, then yes I did screw it in.

 

well...theyre not magic, check them again...remove the relay and jump the wire that connects power to the fan, (I cant remember the terminal numbers off hand make sure your not jumping the signal wire) if it still doesnt come on you gotta start tracing wires towards the battery (now is a good time to test the fuse with a multimeter)

 

I tried everything I could think of .... nothing seems to work. I pretty much eliminated and narrow it down to the following...

1. Fuses and relay are good
2. Fan switch is good
3. Fan motor is good (the fan itself)
4. ECU and obd2-obd1 jumper harness are all good
5. Checked the thermo housing ground and other grounds, everything is good and grounded...
6. And now... Im stuck... my swap is finally done and it runs nicely, just fan wont turn on and it overheats my engine when Im at a stop..

 

can you please explain in details and show me how since i'm not quite sure what you're talking about. Sorry in advance for my lack of experience on this. thanks

 

whats the year/make/model of vehicle? Ill see if I can find a wiring diagram....Ive got mitchell and identafix

 

its a 99 honda civic Si. originally came with b16a2 Thanks

 

What about the wires?

 

Idk about civics but my 97 gsr has an a/c diode that controls the fans. Well it said so in the service manual. I had the same problem. Maybe check that?

 

The rad fan is controled by the ECTS, it supplies a ground to the rad fan relay that in turn supplies either 12V+ or a ground, [depending on MM&Y of car] to the rad fan, ground for your 97GSR and 12V+ for the 99 Civic.

The A/C diode pack in your 97GSR supplies a ground to both the A/C condenser fan and the rad fan, the diode pack is there to prevent the ECTS from supplying a ground to the condenser fan.

Sorry dohcem1 I do not have a wiring diagram for a 99, I do have one for the 98, and it shows the rad fan relay is controled by the ECTS, [or "Radiator Fan Switch"] it supplies a ground to the relays coil, the other side of coil is supplied 12V+ when ign. switch is in the run position, the relay itself is supplied a 12V+ constant, [hot at all times] which would in turn supply 12V+ to rad fan when relay is energized.

So the questions are...
Does the relay have 12V+ constant?
Does the relay have 12V+ when ign. switch is in the run position?
If you supply 12V+ to the relays lead that runs to the rad fan, [black/red on the 98]from either the 12V+ constant at the relay or any 12V+ source does the fan work?
By the sounds of it, it does not, please confirm that you have tried this.
If you have and fan does not work there is a connection problem between the rad fan relays output and the rad fan itself. 94

 

sorry I havent forgot about you yet? been busy as hell at work, Ill see if I can find it today

 

Thanks.

Well, as a reply to fcm, I just tried everything you suggested and everything WORKS. Now I found out that it IS MY grounding that is causing this and not the 12v+ constant. I tried to trace it back to see which ground isn't working. Surprisingly, it is my fan switch grounding side. Now the fan switch WORKS because I bought a BRAND new one for 52$ at honda dealer, so it must be from the plug to the harness. I depin the plug to see if the wire is ok and its fine. Now my question is... HOW could I trace this ground wire back and to where? Its like loom in with the BIG engine harness. Its hard to explain and I know my above explanation ISN'T the best but I hope you gurus can understand it. THanks alot in advance!

Basically,

1. relay/fuses = ok
2. fan = ok
3. Does the relay have 12V+ constant? = yes
4. Does the relay have 12V+ when ign. switch is in the run position? = yes
5. fan switch functioning... = YES
5. is the grounding wires from the fan switch PLUG sending the ground? = NO

 

Ive got the diagram, but I left it at work, sorry...I have to go in tomorrow to do some side work and Ill bring it home and scan it in for ya...it says 2000 si but I checked against the 99 and it was the same diagram. Itll tell ya where that ground wire ends up

 

Ok awesome thanks. Yeh I basically just don't know where that ground wire end up. I would be able to find the break if I could trace it. Hopefully it's not within the engine harness....

 

If you think it's a problem with the the constant ground input to the switch, [black] and you have confirmed it by using a jumper the supply a ground to that terminal on the plug then you can either install a more permanent one or find the problem with the stock lead, all the ground leads for the "engine" harness are grounded in the engine bay, but there are more then a few, and without a detailed ground location schematic it could be very difficult to find.
You can look, [probably already have] for the obvious, you can check/clean/tighten any grounds you know of.

If the problem is a break at a connection, [it's not uncommon to have a low current ground lead "branch off" another ground lead] the connection will be "buried" in the engine harness and the only way to find it is to trace it to it's source, taking apart whatever parts of the wiring harness you need to, easiest done on a bench, the connection will not be a soldered one, it is a metal "wrap around" crimp, a 1/4" - 1/2" of insulation is stripped off the main lead, same with the end of the "branch" lead, the stripped leads are held together and a tool, kind of like a HD staple gun, is used to crimp a narrow metal band around the two leads and it is insulated with tape or shrink tubing, anywayyyy, they can pull apart.
Would be a lot easier to just install a new ground. 94

 

or, the simple and easiest solution. hook it up to a switch or put it to a 12v battery on.

 

O I see. I guess it is WITHIN my engine harness because I just checked again right now, and I've tighten all my grounds and checked ALL the plugs. Again, there is no 12V+ to the fan because there is no ground to the relay fuse box therefore, no power to the fan. I understand that I could just wire it to a switch, but I personally don't like that. I want the car to function correctly and "stock". There's no point to a fan switch which I paid 52$ for and going this far yet, quit near the end (Just my personal opinion please don't take it any other way.). Right now, I want to ask IF theres anyway, I could DIRECTLY wire that fan switch to the relay or to whatever that needed the ground connection to send out 12V+ to the fan? Now, if I could, where do I need to wire this. Here's 2 pictures to make things a lil clearer


theres basically no 12V+ here so that means there's no point for me to wire a ground AT or AFTER this point...



BUT, there IS power here to the relay.. So, again, the question is how and to WHERE do I wire that fan switch ground to around this area. I basically just want to bypass thru the whole engine harness and like FCM said, make a NEW ground connection. But I just don't know where that original wire is grounded to...


Sorrie for alot of repeats but I just want to make it really clear. Thank you for all your help. THis is my last step before I get to drive it. Thanks

 

Hard to tell what the first pix is.

The way it works is the fan switch, [ECTS] should have a constant ground going to it, [either pin] the lead from the other pin goes to the rad fan relays coil, when engine coolant reaches about 190 degrees the rad fan switch closes supplying the rad fan relays coil with a ground, the other side of rad fan relays coil is the switched 12V+, [that you say you have] and that will energize the relay, [turn it on].

You need to test and confirm this, unplug the the 2pin rad fan switch, turn ign. on, then ground the lead running from the rad fan switch plug to the rad fan relay, use a jumper wire from the batt. neg.(-) terminal, if you do not know which lead in the 2pin plug is the one that goes to the rad fan relay, just ground both of them, [one at a time] assuming all is good, grounding one of the lead will turn on the rad fan and you will confirm that the problem is no ground to the rad fan switch, [other wire], that other wire is the one you need to ground.
Do the test above and let me know if the fan works, don't forget to turn on the ign. to the run position, you do not need to start the car. 94

 

sorry it took so long, but here it is




I have it saved a little bigger or you can just print it out, hope this helps

http://i528.photobucket.com/albums/d...ofo/img066.jpg

http://s528.photobucket.com/albums/d...ent=img066.jpg


looking it over , have you checked the number 17 fuse on the inside fuse box, its 7.5 fuse, thats the one that supplies power to the relay....from there you need to check continuity from the coil side of the relay to ground, you will have to use a jumper wire in the plug that goes into the switch (leave it in when your done checking)....after that check to see if there is power at the switch side of the relay. If there is power going in, then check for power going out with a jumper placed in the 2 coil side terminals of the relay. if there is no power coming out than you need a relay....if you have power there then go down to the fan plug ,check for power, and after the fan it goes to ground.....sorry I cant tell you which terminals are what on the relay, but there is a dagram on the side of it that will tell you....If you find a break anywhere in that procedure than you have to start physically tracing wires, but its usually easier to check all the plugs before you start tearing the harness apart. ....make sure you are using a volt/ohm meter or we are wasting are time. not an insult but so many say they check things and all they do is wiggle wires

 

Well ok quick question. How do I do this "then ground the lead running from the rad fan switch plug to the rad fan relay, use a jumper wire from the batt. neg.(-) terminal . . . "
Do I just stick a small wire into the slot of the relay and tap that ground wire? Not quite understand that. Sorrie. By the way, all my fuses are good including the 7.5 fuse. thanks

 

hook a wire up to the neg battery post, then touch it to the green wire on your switch plug, car must be in the "on" position. If the fan comes on, than your problem is either a) the switch or b) the black ground wire is broken somewhere or one of the connections on that wire is bad. that ground will end up at the right rear of the engine.

 

Ok, tried.... the fan did NOT turn on.... so its something wrong with the connection between ground wire and the relay terminal. =/