Top 10 1999 Plymouth Grand Voyager Questions & Answers

My answer:

I answered a similar ? at Yahoo Answers awhile back, and it solved that person's problem on their 1987 Jeep.

Though you weren't very specific as to your 2003 Jeep Grand Cherokee's problem by just saying the fan motor doesn't work, I'm taking it that we are talking about the "radiator fan motor" here.

You most likely have a two-fold problem going on with your radiator cooling fan.

Seeings a new fan motor didn't solve the original non-op problem we can definitely establish that the old fan being bad really wasn't bad at all and NOT the problem to start with.

As with any 12-volt DC automotive motor (whether for the radiator cooling fan, windshield wiper motor, interior passenger compartment cooling/circ fan, etc) a simple disconnected from the car's electrical system test should have been done 1st to make sure the old fan motor was really bad. Too late for that now though. I myself would have seriously doubted that a 6 year old fan motor would have been bad already.

If you had no recent engine or radiator related mechanical work done to the Jeep - as of late - then the problem may not even be a bad wiring harness connection, but you never know.

If all the radiator fan Temp related Sensors & Thermal Switch connectors are properly seated then we need to look at yet another possibility having eliminating a wiring connector type problem.

On most radiators with an electric assist fan(s) there is also an electric Thermo Sense switch (TS) mounted on the radiator itself that has to be working properly otherwise this fan switch could stick in the CLOSED position (set point usually 190 degrees F) leaving the fan to run all the time while the engine is running. Make sure it is connected as to the wiring connector, as I've seen this connection get pulled apart from other engine related work being done or else from a bad connector itself.

If this TS goes bad and someone disconnects it so as to stop the fan from running all the time - then it may look like the fan itself is bad when it really isn't.

On the other hand this TS switch could actually stick in the OPEN position (though this is very rare with this type of Thermal switch), and then the fan wouldn't run at all, and the engine would probably run HOTTER then normal as a dead giveaway. If your engine is running HOTTER then normal I would go directly to this TS and check it for proper operation. It's usually mounted on the radiator fan bracket nearest the radiator with a separate 2-wire wiring connector.

If it's working properly - when the ignition is turned off - the fan should still turn off as it is usually controlled by a timed RELAY circuit as a failsafe. Does it??

Hopefully you don't have any engine cooling problems to start with, but if you do follow the guidelines below:

If the engine thermostat is sticking CLOSED, or indeed stuck CLOSED, that could also cause the fan to run excessively. Running plain water in the engine and not proper 50/50 antifreeze/coolant mix can also cause the engine to run much hotter then normal and thus adds to running the radiator fan more frequently then normal.

Excessive radiator fan running leads to just one thing, and that is worn out bearings. Some of these fans aren't made that good to begin with!

If the fan is indeed 'tired' or has a tendency to try and freeze up there should be safeguards to prevent wiring from burning up.

Most radiators have 2 thermo-switches (TS), one being an ambient radiator surface mounted TS, and the other one being an internal (screwed into) radiator mounted TS. There might even be a 3rd fan TS that is clipped directly to the fan motor case itself to sense an over-temp situation like that from the fan bearings freezing and the fan itself running hotter then normal. Just depends on car maker design.

There is also a TIMER RELAY module incorporated in all CA equipped cars as part of the SMOG packaging for cars sold here in this state. Reason for that is to reset the pre-warm circuit properly when restarting the car back up after shorter run and stop trips. If this relay is bad it could cause the fan to run on longer then normal after shutting off the vehicle, thus causing undue wear and tear on the fan motor also. I used to think it also helped to clear out any fuel fumes from under the hood after running the engine, but could never prove it or have it verified by my own minivan maker when I owned a minivan??

NEVER DRIVE THE JEEP WITHOUT THE FAN MOTOR BEING CONNECTED!! You will surely damage something you don't want to!!!

To check the radiator fan circuit do the following:

I would first disconnect the battery from the circuit, and do any resistive type DVM meter checks first (unless you are unsure of how to do them), and then do the following checks below to check out the fan motor and related sensors/switches with power reconnected. If you have a lot of MEMORY type devices onboard your Jeep (Stereo, GPS, etc) you might want to use a simple 12-volt TEST LIGHT or again a good DVM to trace for a good ~12-volt battery voltage at point-to-point connectors instead, so as not to lose those memory settings.

First check the wiring leading to and from the fan motor itself and the TS (1 or possibly 2) connectors to make sure they are snapped together fully and making good connections. Also check the GROUND WIRE coming off the fan motor connector - as if this ground point is dirty or corroded causing a bad ground return path then the fan motor will appear to be dead as well.

Next check the fan itself for free-play. Is it turning freely or is it very tight or hard to spin?? If so - you have a bad fan and it's time to replace it NOW! (In your case it doesn't appear to be a bad fad fan motor at all.)

If you are handy with a digital volt meter (DVM) connect it in DC series with the fan motor and while running the Jeep measure the current and compare it to a new fan's rating. If it's excessive then the fan motor is on it's way out. Time to replace. (Skip this part too, as your fan is known good.)

VERY IMPORTANT STEP HERE - Also check those 1 or 2 TS switches to make sure they are in the OPEN setting with a COLD engine/radiator. CHECK AGAIN to make sure they CLOSE at the proper engine temp as well. If they don't close at or near 190 degrees F then one or the other (if there are 2 or more in your system) may be bad, and that may very well be your only problem.

If Jeep has added a FUSE or FUSIBLE LINK to the fan circuit make sure you check that part also. It's doubtful though, as the fan circuit is fairly simple by design. A Timer Relay type Switch would be downstream of the/any TS switch(es) by design as well, so I would place my money 1st on a bad TS switch, or a possible bad ground connection 2nd.

Does not appear to be anything else that excessive as it looks to just be isolated to the radiator fan circuit itself.

Hope this helps you out to troubleshoot the problem. Feel free to email me if you still have further ??'s.

Frank

AND THEIR REPLY WAS:

posted by djvanh on Aug 13, 2008

We are being told that it is the PCM that is causing the fan not to work. Can we replace the PCM with a remanufactured one?

Thanks

AND MY REPLY WAS:

I guess I better ask you a couple of ?'s before going any further here - as I'm not getting back any feedback at all as to what I posted previously.

No past history - no past to present attempted fixes - no troubleshooting feedback.....

The reason I say this is because now you are saying > We are being told that it is the PCM that is causing the fan not to work.

This has me asking - WHO is telling you that the Powertrain Control Module is supposedly bad? By WHO I mean - Jeep dealership - auto repair garage - your friend - who?

I need to know what steps you took to get to this new revelation point - as to the fan supposedly not working?

Please be very specific, and not just a 1 or 2 line reply - as that won't help me pinpoint the problem at all. After all - you have the SUV there (wherever you are located state/city wise), and I don't.

Also - do you have the/a service manual (Haynes or Chilton Auto Manual for your year & make Jeep)?

When I get your feedback we can proceed forward.

Thanks,

Frank



1 - Highly degreed in Electronics first of all.

2 - Worked for 2 SEARS AUTOMOTIVE STORES, one on the East Coast and the other one still being the largest SEARS AUTO in CHICAGO at 6-corners. I specialized in troubleshooting all auto electrical problems - including battery testing and charging system testing and repair. Graduate of DeVry in Chicago also!

3 - Troubleshooted, repaired, and replaced many water pumps, thermostats, fans, TS units, and radiators on all types of vehicles and makes and models. I hate those stupid internal water pumps on many of the *** Honda and similar autos as that is the dumbest design I've ever seen! Stay away from buying one of these headaches!! Timing belts (non-metal type) are just as bad!

Im guessing that the van is overheating in the traffic. you are going to need to have someone with an OBDII scan tool look at it the PCM controls those fans when the coolant temp sending unit tells the PCM the temp is so that the PCM needs to command on the fans, Has anyone changed the cooling fan relay?

You can have the ABS disabled although it is not advisable. Keep in mind on icy , wet, slippery roads without ABS you could lock the wheels causing a slide. Be careful on your trip if you decide to do this.

you need to go over your entire wiring harness, under the hood and inside the dash. Start with the ground wire on the battery and work your way inside. It sounds like there is a loose ground wire somewhere

There is a fan relay in the fuse box in the engine compartment. Usually that is the reason why it won't turn off. It fuses in the on position. If you have the manual it will say which one is the fan relay. just pull it out and get a new one. They are not expensive.

Hope this helps

One of two probable problems:
1. The Heater / Air Condition Control is going bad or is bad.
a. Disconnect the negative side of the battery.
b. Remove the Heater / AC face plate off the front. To do this: Remove the two (2) screws on the top lip of the plate.
c. Disconnect the electrical connectors from the rear of the Control Module.
OR
2. The Heater Core is defective and needs to be replaced.
Sorry, but it has to be noted that the dealer or repair shop ($$) can diagnose the system at the Heater / AC Control Module. Also, after you replace this Module: a diagnostic and re-calibration tests are needed to be performed.
Let me know if this helped or if you have additional questions or information. Feel free to contact me at FixYa.com!

Most newer cars do not have drain plug. My 1998 Plymouth and 2000 Chrylser do not have one. You need to remove one side of lower hose to drain.

1999 Plymouth Truck Grand Voyager 2WD 3.8L MFI 6cyl
* The Vehicle Speed Sensor is located Mounted on transmission
* The Sensor - Transmission Speed is located Mounted on transmission

Hope this help (remember comment and rated this).

I have to assume you have lost the cover for it, as the schematic/Map, is on the underside of it.

Sounds like a basic cylinder miss-fire. Common issues are spark plugs, wires, coil, and fuel injectors,
is the check engine light on when the engine is running ?