fan doesn't turn on help, got power in and out of the temp sensor

[juanjose]

Well my car started overheating, and i started troubleshooting. My problem was that my fan doesn't want to turn on. I tried changing the temp sensor and it didn't help, the wierd thing is, both fans turn on when i unplug the temp sensor. With the car on after a while, i checked power going out of the sensor and both wires had power so i know is not the temp sensor anymore. If any of you guys can help me out get this problem solved, i appreciate it.

 

[juanjose]

anybody ?

 

[asexton6969]

Check the radiator fan relay.

1 Remove radiator fan motor relay from relay box inside engine compartment.
2 Check for continuity between terminals 1 and 3 . Continuity should exist.
3 Check for continuity between terminals 4 and 5 . Continuity should not exist.
4 Connect 12 power supply between terminals 1 and 3 .
5 Check for continuity between terminals 4 and 5 . Continuity should exist.
6 If continuity is not as specified, replace relay.

Picture included:

Whoops anyone able to resize that for me would be appreciated.

After that check Radiator Cooling Fan Control Module

1 Disconnect engine coolant temperature sensor electrical connector and connect an ohmmeter between sensor terminals.
2 Measure resistance between terminals. 9.0-11.0 Kohms @ 77°F 0.6-0.8 Kohms @ 212°F
3 If resistance is not as specified, replace sensor.

 

[asexton6969]

Thought I would add this diagram so you can eliminate possible problems one at a time.

 

[juanjose]

thank u guys, well i don't have a tester so all i did was exchange the relays from the ones from the headlights and fogs and nothing happen, i've been reading and found the ecu controls the fans and that might be my problem i think; only thing weird is when i unplug the temp sensor both fans came on and they stay on all the time, if that helps thanks.

 

[luv2rallye]

the wierd thing is, both fans turn on when i unplug the temp sensor. With the car on after a while, i checked power going out of the sensor and both wires had power so i know is not the temp sensor anymore.

This tells me the problem IS your sensor. Both sensor wires should not have power. The black should be connected to ground through ECU pin 92 (must go here - not to chassis or engine ground). The black/white should have between 0-5V depending on the sensors resistance. This is with your testers negative lead always connected to chassis or engine ground (or battery negative).

 

[juanjose]

This tells me the problem IS your sensor. Both sensor wires should not have power. The black should be connected to ground through ECU pin 92 (must go here - not to chassis or engine ground). The black/white should have between 0-5V depending on the sensors resistance. This is with your testers negative lead always connected to chassis or engine ground (or battery negative).

My friend who's a general mechanic said the same thing at first and after we change the sensor with a used one of my old 7bolt and no change he check the wires in and out on the sensor, when the car was cold one of the wieres light up in the tester(dont know what kind or how it works) and after a while he show me again and both wires light up in the tester so he told me it wasn't the sensor and he was goin to search what is it but i want to do the same and prob fix it myself

 

[luv2rallye]

Sounds like it's the sensor wires not goin to where they should. Check if you have near zero resistance on the sensors black wire to ground (can use any ground for testing). If that's not your problem check if the black/white has continuity to ECU pin 83.

 

[luv2rallye]

... Measure resistance between terminals. 9.0-11.0 Kohms @ 77°F 0.6-0.8 Kohms @ 212°F

WRONG!!! That spec is for 2g NT.
2g turbo is 2.1k-2.7k @ 68F, 0.26k-0.36k @ 176F.

 

[asexton6969]

WRONG!!! That spec is for 2g NT.
2g turbo is 2.1k-2.7k @ 68F, 0.26k-0.36k @ 176F.

Good thing you knew, I pulled that from ALLDATA.

 

[juanjose]

Well im waiting on my friend ### hes the one with tester, so i got three question for u guys the i found behind the radio.

1. This connector was losse when i took the radio and the side panels off but i cant find where it goes. Can anyone tell me

2. Is this a e-prom ecu, i think it is but i'm not sure.

3. I got a handspring visor for free but don have the software to make run any help in that, thanks.
and the pics

 

[juanjose]

well i checked with the thester and i have 0.1 resistance on the black wire to ground and i have continuity on the black/white to the 83 pin in the plug the connects to the ecu and a checked the three sensors, new one in the car and two used ones and first one was 1.715,second one 1.761 and the one on the car 1.651 any help thanks

 

[luv2rallye]

I assume those sensor values are k ohms (1.651k ohms) measured with the sensor disconnected. If so they sound ok.

First some questions (please answer each by it's number):
1) Do you have the two stock 2 speed fans, wiring, and ECU? You don't have aftermarket fans or them wired together or anything - everything is factory?
2) Any wiring/ECU mods of any kind (eg. eprom chip mod) or anything changed/added just before this started happening (eg. radio/amp added/modified)? Anything else that doesn't work right?
3) Has this problem always been there? If not when did it start?
4) You say w/o the sensor both fans run. Do they turn on immediately after sensor disconnect or does it take some time (eg. 10 seconds or 1 minute, etc)?
5) You say after sensor disconnect both fans stay on all the time. Even if you plug the sensor back in? When do they turn off - only when turn car off?
6) If you unplug the sensor and then start the car do the fans run or is it only when you unplug it while car is running?
7) Try unplugging the sensor and shorting the two harness wires together both before and after the car is running. What result?
8) I assume the fans don't ever run if you unplug the fan relays, correct?
9) Do you have another ECU you could try?

 

[juanjose]

1. Everything is stock fans, ecu ect......
2. Nothing, all stock.
3. No, started two weeks ago.
4. After 2 secs they turn on.
5. If i plug the sensor right back they turn off, but if i wait for like 5 sec and then plug in the sensor they stay on until i turn off the car.
6. The fans will run.
7. before starting the car they stayed off but if i do it qith the car on they just keep running
8. well if i just unplug one relay for the radiator fan still works but slower, ihave tow take 2 off so it can stop.
9. no i dont

well over the weekend started workin the two times i tested the car, so i used it today and started happenin the same thing: when i got home it work a couple of times but i had to turn the ac on for like 10 seconds and then the radiator fan would sty on for like a min so there u go i appreciate the help.

 

[Hotmodder]

To get rid of all your troubles.... Just wire both fans up to a switch. Turn them on when you get in, off when you get out... Problem solved...

 

[juanjose]

To get rid of all your troubles.... Just wire both fans up to a switch. Turn them on when you get in, off when you get out... Problem solved...

i was thinking on doing that this weekend if i cant fix it by then, i saw a thread when u put take two wires of the ecu to a switch and u can have one fan on or two, and if u want to u can leave the switch in the middle and the ecu will take over (in case i can fix it someday)

 

[luv2rallye]

i was thinking on doing that this weekend if i cant fix it by then, i saw a thread when u put take two wires of the ecu to a switch and u can have one fan on or two, and if u want to u can leave the switch in the middle and the ecu will take over (in case i can fix it someday)

Yep that is my mod and the post is here (post 11): http://www.dsmtuners.com/forums/pro...-issue-plus-wiring-them-up.html#post151319397.

Well all your answers (post 14) to my questions are normal. Therefore I think your problem is the ECU. Take it apart and look for leaking capacitors (common problem) and/or there is a rotten egg smell.

 

[juanjose]

Thanks I saw the diagram but my question is where B and E go to after the swicht, thanks

 

[luv2rallye]

Thanks I saw the diagram but my question is where B and E go to after the swicht, thanks

They connect to chassis ground (any metal body part that is connected to battery negative).

 

[juanjose]

Just want to say thanks to luv2rallye for the support this past weeks. Today i did the switch mod for the fan and just took me 20 min and works good so thanks for all the information i learn a lot from this experience.
luv2rallye just a quick question can u answer the question on post 11 thank u.

 

[luv2rallye]

from post 11:
1) don't know
2) eprom according to DSMLink - FAQ - EPROM
3) don't know

 

[spooln4fun]

Just for an update the mod luv2rallye made is still up and working properly Big thumbs up and thanks luv2rallye