How to troubleshoot a jeep PWM fan relay test?

Radiator Fan Motor Circuit Wiring Diagram (1999-2003 4.0L Jeep Grand Cherokee). TIP 1: The way I’ve designed the Jeep PWM fan relay test, you’ll need a scan tool that can read live data (not a code reader), since you’ll need to keep an eye on the engine’s coolant temperature with it.

Why does my Jeep Grand Cherokee Fan quit working?

In this one we take a stab at permanently fixing a common issue with the 1999-2004 Jeep Grand Cherokee. The electric cooling fan will quit working, and your jeep will overheat, due to a failure in the electronic fan control relay. This is a heat related failure and I add a large heat sink and relocate the relay to try and avoid further issues.

What is the PWM code for a Jeep Grand Cherokee?

This tutorial will help you to diagnose the Pulse Width Modulated (PWM) fan relay on the 1999-2003 Jeep 4.0L Grand Cherokee SUVs and/or the codes P1491 ( Radiator Fan Control Relay Circuit ). The dealer, at the time of this writing, will charge you $95 (US) to diagnose it.

How big is the fuel pump relay on a Jeep Grand Cherokee?

Fuel Pump Relay, Automatic Shut Down Relay, Powertrain Control Module, Transmission Control Relay (4.7L)

What kind of fan does a Jeep Grand Cherokee have?

APPLIES TO: This tutorial applies to the following vehicles: 1999, 2000, 2001, 2002, 2003 4.0L Jeep Grand Cherokee. Radiator Fan Motor Circuit Wiring Diagram (1999-2003 4.0L Jeep Grand Cherokee).

What are the symptoms of a bad fan relay?

Symptoms Of A Bad PWM Fan Relay. FAN RELAY TEST 1: Checking For Power. FAN RELAY TEST 2: Checking For Ground. FAN RELAY TEST 3: Checking For The Relay Control Signal. FAN RELAY TEST 4: Calculating the Amperage Draw of the Fan Motor.

Where is the fan relay on a jeep?

But if you have more time than money, you can easily diagnose it yourself, and I’ll show you how. Testing the fan relay is easy, the hardest part is getting to it, since Jeep in all its wisdom, located the fan relay behind the right side (passenger side) of the front bumper and you’ll probably have to remove it to access it.

APPLIES TO: This tutorial applies to the following vehicles: 1999, 2000, 2001, 2002, 2003 4.0L Jeep Grand Cherokee. Radiator Fan Motor Circuit Wiring Diagram (1999-2003 4.0L Jeep Grand Cherokee).

What causes a bad or failing blower motor relay?

Blown fuses. One of the first symptoms of a bad or failing AC blower motor relay is a blown AC blower motor relay circuit fuse. If the blower motor relay develops any sort of problem that hinders its ability to properly limit and distribute power, it may cause the blower motor fuse to blow. Any sort of electrical spikes or excessive current…

What does a fuse do on a Jeep Grand Cherokee?

Fuse box diagram (fuse layout), location, and assignment of fuses and relays Jeep Grand Cherokee (WJ) (1999, 2000, 2001, 2002, 2003, 2004, 2005). A fuse is an element for protecting the electrical system. A fuse will trip (i.e. it will blow) in the event of a failure or improper interventions in the electrical system.

How does the cooling fan work on a Jeep Cherokee?

Jeep Cherokee Electric Cooling Fan Diagnosis & Repair. When the air-conditioning is used the engine ECU grounds the A/C relay coil allowing current to flow through it. This activates the A/C relay which then supplies current to the A/C clutch, fan diode assembly and cooling fan relay.

How to check battery voltage in Jeep Cherokee?

Check for battery voltage at terminal 2 of the fan relay connector (Fig. 43). If battery voltage is not present replace the fan diode assembly. With engine running, A/C on, and fan relay removed, check for battery voltage at terminal 2 of fan relay connector (Fig. 43).

Is there a way to override a jeep cooling fan?

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Where is the blower motor relay located on a 2003 Jeep Wrangler?

Where is the blower motor relay located on a 2003 Jeep Wrangler X. I am trying to find out why my blower does not work on high but does work on the three lower setting. I have recently replaced the bl…

When does the first relay turn on the fan?

1ST RELAY TURNS ON FAN WHEN TEMP SWITCH IS ACTIVATED 5 AMP FUSE SIGNAL CIRCUIT 12V SWITCHED (IGNITION OR FUSE PANEL) Power “ON” when key is in the “RUN” position. 86 87 30 85 Optional override switch turns on fan, by-passing temp sensor and A/C relay.

Do you need a relay kit for a cooling fan?

A relay kit, our part number CCFKRL, will include everything you need to properly wire up your electric cooling fans, with the exception of additional wiring needed to complete all of the circuits. The first part of the installation is to install the electric fan to your radiator, and remove the mechanical fan.

Where is the fuse on an electric fan?

OPTIONAL 2ND RELAY OVERRIDES TEMP SENSOR AND TURNS ON FAN WHEN A/C IS TURNED ON TEMP SENSOR SWITCH IN RADIATOR COOLANT OR OPTIONAL ADJUSTABLE FAN SWITCH WITH RADIATOR PROBE (GROUND SWITCHING, NON- VARIABLE SPEED ONLY) 5 AMP FUSE POWER SOURCE SHOULD BE BATTERY OR JUNCTION BLOCK NEAR BATTERY FAN

Where are the fuses on a Jeep Cherokee?

Jeep Cherokee (XJ) 1997 – 2001 Fuse & Relay Information FUSE NUMBER FUSE CURRENT RATING CIRCUIT INFORMATION (What the fuse is fo 1 25 Amp Power outlet – Located top left column i 2 25 Amp Cigar lighter 3 10 Amp Left headlamp

Why does my 2003 Jeep Grand Cherokee overheat?

i have a 2003 ,overheated. solution: change the fan motor. faulty fan motors due to faulty windings from factory. LISTEN TO THIS IMPORTANT MESSAGE!!!!!!!!!!!!!!!!!! For anyone having overheating problems with their Jeep Grand Cherokees take these necessary steps before taking your vehicle to a dealership………. 1.

Where is the cooling fan relay in my 2004 Jeep Grand Cherokee?

Where is the cooling fan relay in my 2004 Jeep Grand Cherokee? The hole under the passenger headlight has nothing and the relays are not in the fuse box either. Clicking this will make more experts see the question and we will remind you when it gets answered.

What causes a Jeep Grand Cherokee to overheat?

Low coolant caused from a leak can cause overheating and possible engine damage. A thermostat not opening could also cause overheating even if there’s no leak. Caution DO NOT open the radiator cap on any hot cooling system. With that being said, one very common problem is the radiator’s cooling fan not working.

What are the symptoms of a bad PWM fan relay?

Symptoms Of A BAD PWM Fan Relay. The most obvious symptom of a BAD PWM fan relay is that your Jeep is gonna’ overheat. You’ll also see one or all of the following symptoms as the engine overheats:

How much does a PWM fan relay test cost?

The dealer, at the time of this writing, will charge you $95 (US) to diagnose it. But if you have more time than money, you can easily diagnose it yourself, and I’ll show you how.

Where are the fuse panels on a Jeep Wrangler?

Here you will find fuse box diagrams of Jeep Wrangler 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 and 2006, get information about the location of the fuse panels inside the car, and learn about the assignment of each fuse (fuse layout) and relay.

What are the symptoms of a bad cooling fan relay?

1. Engine running hot One of the first symptoms commonly associated with a bad or failing cooling fan relay is an engine that runs hot or overheats. If you notice that your engine is running at higher temperatures than normal, that may be a sign that the relay is not functioning properly.

Why does my Jeep overheat when I drive?

SOLVED: My Jeep overheats while sitting idle. When I drive – Fixya My Jeep overheats while sitting idle. When I drive, the gauge goes down quickly. I have had thermostat and fan changed. I have also had the radiator flushed. What can it be? I have a 2004 Jeep Cherokee that keeps overheating.

What are the symptoms of a bad coolant temperature switch?

1. Poor fuel economy 2. Black smoke from engine 3. Overheating engine 4. Check Engine Light comes on The coolant temperature sensor, also known as the coolant temperature switch, is an engine management system sensor that is used to monitor the temperature of the engine’s coolant.

How can I tell if my Jeep Grand Cherokee is overheating?

Coolant temp sensors don’t measure air temp. If there was no coolant in your engine the gauge will read cool when acualy the engine will be turning itself in to a molten pile of steel. Sounds to me like your head gasket blew out, or wore you cracked a head. There is a easy way to tell.

Why is the fan not working on my Jeep Grand Cherokee?

The fan wiring is some of the more vulnerable wiring in your Grand Cherokee. You can test the voltage going from the fan relay to the fan itself. If it is getting 12+ volts, the fan should be coming on. But if it’s not, which means the fan has gone bad.

What to do if your Jeep Grand Cherokee radiator is not working?

The first thing that you would want to do is locate the fuse for your Grand Cherokee’s radiator fan and make sure that it hasn’t blown. If it is blown, replacing the fuse will only solve the problem for a very limited period of time. Unless the wiring issue is fixed, the fuse will blow again. The wiring harness itself can go bad.

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