Go Back   DodgeForum.com > Dodge Vans & CUVs > Dodge Caravan
Sign in using an external account
Register Forgot Password?


Dodge Caravan The Dodge Caravan is the best selling mini van from Dodge. How many Dodge Caravan owners here at DodgeForum.com would agree? Discuss it now!
Sponsored by Dodgetruckparts
Click Here


Cooling Fan Relay

Reply
 
 
 
 
Thread Tools Search this Thread
  #1  
Old 06-10-2010, 08:02 PM
josh2500 josh2500 is offline
Rookie
 
Join Date: Jan 2006
Location:
Posts: 77
Default Cooling Fan Relay

Im working on a friend of mines van. The cooling fans will work sometimes and sometimes they wont. I jumped the fan motors with a jumper wire and both run when jumped. The fuse is good. I checked the two plugs that plug into the motors and both prongs on both plugs are grounded. One should be hot and the other grounded. However, like i said, both are grounded. I am thinking i need a cooling fan relay? Anyone else dealt with this? I hate to spend a hundred bucks and that not be the problem. Thanks for any help.
This ad is not displayed to registered and logged-in members.
Register your free account today and become a member on Dodge Forums!
__________________
05 Ram 2500 4x4 CTD, automatic, 4 door short bed, edge juice with attitude, straight pipe, k&n intake, hell bent leveling kit, Smoked Recon Clearance Lights, Pro Comp 35's, Pro Comp wheels
Reply With Quote
  #2  
Old 06-10-2010, 11:43 PM
master tech's Avatar
master tech master tech is offline
Multi-section Moderator
 
Join Date: Apr 2007
Vehicle: Mits P/U , Dodge avenger(1996) .
Location: San Bruno ,Ca
Posts: 10,611
Leonard Pierce
Default

I use an drb3 to actuate the fans. If they come on the relay in most cases is good. You may want to look at the temp sensor or wiring. Do you have a ck engine lite on?
__________________
Dodge Master Tech.
Reply With Quote
  #3  
Old 06-10-2010, 11:58 PM
josh2500 josh2500 is offline
Rookie
 
Join Date: Jan 2006
Location:
Posts: 77
Default

Check engine light was on. However, we live about 30 minutes from anywhere that can read the code. The tempature gauge is working. The reason i suspect the relay is because both prongs on the plugs are grounded. Even if the tempature sensor was bad shouldnt one of the fans come on when the ac is turned on?
__________________
05 Ram 2500 4x4 CTD, automatic, 4 door short bed, edge juice with attitude, straight pipe, k&n intake, hell bent leveling kit, Smoked Recon Clearance Lights, Pro Comp 35's, Pro Comp wheels
Reply With Quote
  #4  
Old 06-11-2010, 12:09 AM
master tech's Avatar
master tech master tech is offline
Multi-section Moderator
 
Join Date: Apr 2007
Vehicle: Mits P/U , Dodge avenger(1996) .
Location: San Bruno ,Ca
Posts: 10,611
Leonard Pierce
Default

Depends on the year of the van, 1996 to 2000 is on the frame rail under the air filter box.2001 to 2007 is in the front bumper on the passenger side.
__________________
Dodge Master Tech.
Reply With Quote
  #5  
Old 06-11-2010, 12:14 AM
josh2500 josh2500 is offline
Rookie
 
Join Date: Jan 2006
Location:
Posts: 77
Default

I know where the relay is. But doesnt both prongs on both connectors being grounded sound like a stuck relay? Is there anyway to test the relay?
__________________
05 Ram 2500 4x4 CTD, automatic, 4 door short bed, edge juice with attitude, straight pipe, k&n intake, hell bent leveling kit, Smoked Recon Clearance Lights, Pro Comp 35's, Pro Comp wheels
Reply With Quote
  #6  
Old 06-11-2010, 12:29 AM
master tech's Avatar
master tech master tech is offline
Multi-section Moderator
 
Join Date: Apr 2007
Vehicle: Mits P/U , Dodge avenger(1996) .
Location: San Bruno ,Ca
Posts: 10,611
Leonard Pierce
Default

Not really. plug in a known good relay and recheck.
__________________
Dodge Master Tech.
Reply With Quote
  #7  
Old 06-11-2010, 12:57 AM
master tech's Avatar
master tech master tech is offline
Multi-section Moderator
 
Join Date: Apr 2007
Vehicle: Mits P/U , Dodge avenger(1996) .
Location: San Bruno ,Ca
Posts: 10,611
Leonard Pierce
Default

RADIATOR FAN RELAY
DESCRIPTION
The radiator fan relay is a solid state type and is located under the left front headlamp module Radiator Fan Relay Refer to WIRING DIAGRAMS for a circuit schematic.

OPERATION
The solid state radiator fan relay is controlled by the Powertrain Control Module (PCM) by way of a Pulse Width Modulated (PWM) signal. The relay control circuit supplies a 12 volt signal to the PCM. The PCM then pulses the ground circuit to achieve fan on time. The relay provides a voltage to the fan motors which is proportional to the pulse width it receives from the PCM. The duty cycle ranges from 30% for low speed operation, then ramps-up to 100% for high speed operation. This fan control system provides infinitely variable fan speeds, allowing for improved fan noise, A/C performance, better engine cooling, and additional vehicle power.

To control operation of the relay, the PCM looks at inputs from:

•Engine coolant temperature
•A/C pressure transducer
•Ambient temperature from the body controller
•Vehicle speed
•Transmission oil temperature
The PCM uses these inputs to determine when the fan should operate and at what speed. Refer to Specifications - Radiator Fan Operation in this section.
__________________
Dodge Master Tech.
Reply With Quote
  #8  
Old 06-11-2010, 01:00 AM
master tech's Avatar
master tech master tech is offline
Multi-section Moderator
 
Join Date: Apr 2007
Vehicle: Mits P/U , Dodge avenger(1996) .
Location: San Bruno ,Ca
Posts: 10,611
Leonard Pierce
Default

OPERATION
The solid state radiator fan relay is controlled by the Powertrain Control Module (PCM) by way of a Pulse Width Modulated (PWM) signal. The relay control circuit supplies a 12 volt signal to the PCM. The PCM then pulses the ground circuit to achieve fan on time. The relay provides a voltage to the fan motors which is proportional to the pulse width it receives from the PCM. The duty cycle ranges from 30% for low speed operation, then ramps-up to 100% for high speed operation. This fan control system provides infinitely variable fan speeds, allowing for improved fan noise, A/C performance, better engine cooling, and additional vehicle power.

To control operation of the relay, the PCM looks at inputs from:

Engine coolant temperature
A/C pressure transducer
Ambient temperature from the body controller
Vehicle speed
Transmission oil temperature
The PCM uses these inputs to determine when the fan should operate and at what speed.

This is for the 2001 thru 2007.
__________________
Dodge Master Tech.
Reply With Quote
  #9  
Old 06-12-2011, 11:42 AM
mgoglia mgoglia is offline
Registered User
 
Join Date: Jun 2011
Posts: 1
Default looking for PWM relay electrical details

Hi, I'm new to this forum and have a question about the PWM Relay function.
I recently replaced the PWM relay on my 2002 jeep grand cherokee and it worked fine for a few days, then it stopped working. I bought a replacement from Rock Auto parts and it came with a new connector. I replaced the relay and connector. I also cleaned the metal surface where it mounts and applied white thermal grease. I checked the Fan to see it it turned freely and checked the operating current draw and it was ~25 amps, when connected directly to the battery. I wonder if one of the crimped wires came loose (need to check). Now for the question: What is the voltage level and frequency/pulse width of the signals that are sent to the PWM relay to control the fan? Does anyone have a schematic of the relay itself? I'm thinking or replacing it with a more robust relay.
Thanks,
Matt
Reply With Quote
Old 06-12-2011, 11:42 AM
 
 
 
Reply




Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Join DodgeForum
Advertising

Featured Sponsors
Vendor Directory
Our Sponsors
All times are GMT -4. The time now is 12:17 PM.

Internet Brands, Inc.


Contact Details & Emails