WTB 2005 hydrolic fan. I think mine is gone :(

1994viper

Enthusiast
Joined
Jun 15, 2008
Posts
626
Reaction score
0
Location
Toronto, Ontario
Hi all. I made a post about how my power steering felt tight while at idle and when the car is warm earlier. The car war running hotter than the proper operating temperature at those times.. I eliminated one suspect, the ps pump. So now ii think it must be caused by a restrictive hydraulic fan, as the steering stops working only when the car gets hot. I don't think its the rack because usually when they go, they go, and there is now steering car being cold or hot. correct me if im wrong. Does anyone have a working unit for sale?
or any other ideas will be appreciated
Thanks guys
 

Viper X

Former VCA National President
VCA Officer
Joined
May 1, 2004
Posts
3,471
Reaction score
2
Jon B at Parts Rack can likely get you one too.
 

Thom

Enthusiast
Joined
May 1, 2012
Posts
61
Reaction score
0
Location
Southern Calif.
The speed of the hydraulic fan is controlled by a signal from one of the electronic modules. Before I would blindly replace the hydraulic motor, I would measure this signal to see if the electronic module is running the fan enough.
 

Viper X

Former VCA National President
VCA Officer
Joined
May 1, 2004
Posts
3,471
Reaction score
2
The speed of the hydraulic fan is controlled by a signal from one of the electronic modules. Before I would blindly replace the hydraulic motor, I would measure this signal to see if the electronic module is running the fan enough.

What Thom says is true.

However, in order for this to happen, the programming in the computer that controls fan turn on temp would have to have failed or have been re-flashed incorrectly, which is possible but not likely. It is worth checking on however as any dealer with the correct tool and check this for you before you go to the trouble or expense of changing the hydraulic fan motor.

I had the computer re-flashed in my 2004 Paxton car to turn the hydraulic fan motor on sooner, i.e. at a lower temperature, to help the engine run cooler.

Good luck.
 

Thom

Enthusiast
Joined
May 1, 2012
Posts
61
Reaction score
0
Location
Southern Calif.
A software failure (mentioned above by Viper X) of the fan speed only is extremely unlikely.

However, since this fan speed signal travels from the electronic module to the hydraulic modulator(right name?) via a dedicated wire, a connection problem could cause fan speed problems. Also, a bad hydraulic modulator (hope I got the name right; it's the gadget that allows hydraulic pressure to the fan motor based on the electrical signal from the electronic module) could also cause overheating. I don't know if the modulator has to have a ground return path for the signal, or if the signal return path has a dedicated wire.

If you want to measure this signal and/or check your fan speed, simply turning on the A/C with the engine fully warmed up will probably turn on/up the hydraulic fan motor signal.

The signal is a pulse width modulated signal, and you can measure it with an ordinary meter. The higher the signal voltage, the faster the hydraulic motor should run. If I'm remembering the electrical manual correctly. The signal probably should be lower than 12~13 volts, as hydraulic motors are VERY powerful.

Anyway, I'd measure this signal while observing fan operation before replacing parts. A dealer or someone with a DRB III should be able to put the cooling fan into a test mode where the signal can be measured and the fan rpm can be measured and compared to known good values.

One other thing...because the fan runs on power steering fluid, any kind of air or lack of fluid in the power steering system will cause problems. As will slippage of the power steering pulley, either on the serpentine belt or on the pump shaft. So check your belt tension and condition, as well as pulley to shaft tightness and pulley key integrity. Assuming it has a key; most power steering pulleys do, and keys have been known to break, fall out, or not get reinstalled.
 
Last edited:

labtec

Viper Owner
Joined
Dec 30, 2009
Posts
155
Reaction score
0
Location
Maryland
I have to order complete cooling fan assembly for my 04 today. A small piece broke off the plastic fan blade which cannot be bought separately from the assembly which *****. Best price I have found is $729 + core charge.
 

Gary Weeks

Viper Owner
Joined
May 26, 2008
Posts
100
Reaction score
0
Location
Dickinson Texas
If you unplug the water temp sensor wire at the thermostat housing the fan should run on high speed if everything is working right.
 

labtec

Viper Owner
Joined
Dec 30, 2009
Posts
155
Reaction score
0
Location
Maryland
missed it by "that much!".....just ordered mine last week for $800 (core return $85) from the stealership
 
Top