General Maintenance & Repairs Leaks | Squeaks | Clunks | Rattles | Grinds

Strange cooling fan issue?

Thread Tools
 
Search this Thread
 
Old 07-08-2013, 05:53 PM
  #1  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default Strange cooling fan issue?

Both low spd fans work great but when its time for high spd fans to come on only the driver side fan goes into high spd. The passenger side fan shuts off.

When the driver side is in high spd it will bring down the temp enough to go into low spd settings. Then both fans continue in low spd like normal.

What's up with this any clue?


My fan settings with a 160 t stat...
low spd on 194
low spd off 186
high spd on 198
high spd off 194
Old 07-08-2013, 08:10 PM
  #2  
10 Second Club
iTrader: (3)
 
MontecarloDrag's Avatar
 
Join Date: Aug 2005
Posts: 889
Likes: 0
Received 4 Likes on 4 Posts

Default

There are 3 FAN relays. If I'm not mistaken the relay 2 is bad, replace it and it should fix it.
It is located in the underhood fuse box, the middle one
Old 07-08-2013, 08:20 PM
  #3  
TECH Fanatic
iTrader: (3)
 
sreve's Avatar
 
Join Date: Nov 2006
Posts: 1,101
Likes: 0
Received 2 Likes on 2 Posts

Default

Sounds like a relay fell out.
Swap out fan relay 2 the only time it's used is for
hi-speed right fan
Old 07-08-2013, 08:39 PM
  #4  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

Thanks guys. I tried switching the #1 and #3 relays to see if any change. No change. Also checked the 2 fuses and they are good.
#2 relay is the conclusion I was coming to. I was just looking at the electrical schematic and it looks like the low spd fan is in series while the high spd is in parallel which includes #2 relay. So it would make sense that #2 relay is probably the bad apple. Ill get a new one and see how it goes.

Last edited by senicalj4579; 07-08-2013 at 08:45 PM.
Old 07-09-2013, 08:35 AM
  #5  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

Update...

replaced all 3 relays and the 2 cooling fan fuses. Not fixed.
Old 07-09-2013, 09:18 AM
  #6  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

Tried commanding the high spd fan to come on with no luck. Pass side fan does not run in high spd.
Old 07-10-2013, 06:51 AM
  #7  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

I guess its time to start tracing wires.
Can anyone tell me what wire/wires to target?
I imagine it must be somewhere from the #2 relay but I don't have a good diagram.
Old 07-10-2013, 08:03 AM
  #8  
10 Second Club
iTrader: (3)
 
MontecarloDrag's Avatar
 
Join Date: Aug 2005
Posts: 889
Likes: 0
Received 4 Likes on 4 Posts

Default

Originally Posted by senicalj4579
I guess its time to start tracing wires.
Can anyone tell me what wire/wires to target?
I imagine it must be somewhere from the #2 relay but I don't have a good diagram.
Here you go
Attached Files
File Type: pdf
Cooling Fans [5.7L].pdf (41.7 KB, 97 views)
Old 07-10-2013, 08:31 AM
  #9  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

Originally Posted by MontecarloDrag
Here you go
Thanks a lot
Old 07-10-2013, 12:00 PM
  #10  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

Swapped the fan motors with each other just for the heck of it and no change. Cant be the fan motor.

Looked for obvious wire issues with no luck. Might have to take it somewhere to have the correct wire paths tested. I'm not great at diagrams. Any help would be appreciated.
Old 07-10-2013, 02:02 PM
  #11  
sawzall wielding director
iTrader: (4)
 
G-Body's Avatar
 
Join Date: Sep 2004
Location: Downers Grove, IL
Posts: 3,120
Received 8 Likes on 8 Posts

Default

If thats the case, it looks like your not getting power to terminal C4 (the red wire) on relay #2. Check that wire for 12V. It could also have 12v with the fans off and then drop to zero when the fan trys to engage. So also check it with a load (the fan) on it.
Old 07-10-2013, 03:09 PM
  #12  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

Originally Posted by G-Body
If thats the case, it looks like your not getting power to terminal C4 (the red wire) on relay #2. Check that wire for 12V. It could also have 12v with the fans off and then drop to zero when the fan trys to engage. So also check it with a load (the fan) on it.
Thank you
C4 (red wire to relay #2) has 12+v with fan off and on. Whats next to check?
Old 07-11-2013, 07:57 AM
  #13  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

Any ideas?
Old 07-11-2013, 09:58 AM
  #14  
sawzall wielding director
iTrader: (4)
 
G-Body's Avatar
 
Join Date: Sep 2004
Location: Downers Grove, IL
Posts: 3,120
Received 8 Likes on 8 Posts

Default

That does get a little weird then. Try checking for 12v at pin C6 of fan relay #2, it should always have 12v. If thats not it, try checking for a ground signal at pin B4 of fan relay #2, it should be grounded when the computer is calling for high speed fans. If all that fails, unplug relay #2 and 3 and try putting a jumper wire between terminals C4 and B6 of relay #2 that should make your right fan run full speed. Use a decent size jumper, at least 14 gauge, and it will probably spark as you connect it.
Old 07-11-2013, 01:24 PM
  #15  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

Originally Posted by G-Body
That does get a little weird then. Try checking for 12v at pin C6 of fan relay #2, it should always have 12v. If thats not it, try checking for a ground signal at pin B4 of fan relay #2, it should be grounded when the computer is calling for high speed fans. If all that fails, unplug relay #2 and 3 and try putting a jumper wire between terminals C4 and B6 of relay #2 that should make your right fan run full speed. Use a decent size jumper, at least 14 gauge, and it will probably spark as you connect it.
Thanks again you have been a great help.

c4 and c6 both have 12v

I probed B4 with the test lamp. Clamp on +. Commanded high spd fan on. Test lamp did NOT light up. So does this mean for sure its a ground or could it still be something else?
Old 07-11-2013, 02:13 PM
  #16  
sawzall wielding director
iTrader: (4)
 
G-Body's Avatar
 
Join Date: Sep 2004
Location: Downers Grove, IL
Posts: 3,120
Received 8 Likes on 8 Posts

Default

That sounds like there is a problem with the wire between pin B4 of relay #2 and splice #166, because your PCM is sending a ground signal for high speed to relay #3 but not to relay #2. Trace the wire from pin B4 of relay #2 back towards the PCM and see if you can find a cut, break, or bad splice.
Old 07-11-2013, 02:15 PM
  #17  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

Originally Posted by G-Body
That sounds like there is a problem with the wire between pin B4 of relay #2 and splice #166, because your PCM is sending a ground signal for high speed to relay #3 but not to relay #2. Trace the wire from pin B4 of relay #2 back towards the PCM and see if you can find a cut, break, or bad splice.
Thanks! Would you happen to have an idea of where the splice is?
This is going to suck lol
Old 07-11-2013, 02:58 PM
  #18  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

I OHMed out #33 in the wire harness to B4 (#2 relay) and then C10 (#3 relay). C10 showed .2 - .5 ohm and B4 showed 0.

I think this confirms what you said G-Body.

Thanks for the help big time. I will begin tracing this dark blue wire.

If anyone has any idea of where the splice is or anything please post.
Old 07-12-2013, 12:25 PM
  #19  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

G-Body...If I cant find damage to the wire or if I do not want to tear up the whole jacket looking for the wire cant I just jump C10 #3 relay with B4 #2 relay?
Old 07-12-2013, 04:57 PM
  #20  
10 Second Club
Thread Starter
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

There's no way I'm going to find the damaged wire unless the intake and other things come off the car. It might even be behind the firewall for all I can tell. So I decided to just jump C10 #3 relay with B4 #2 relay. Works great. Thanks for the help G-Body



Quick Reply: Strange cooling fan issue?



All times are GMT -5. The time now is 04:49 PM.