Best Answer

Replace your thermostat in the cooling system. It works fine on the open highway because the air flow is great enough to cool the motor.


if the fan has stopped spinning but still works when tested with external power

Check your Pulse Width Modulator ( Radiator Fan Relay ) it is located behind the ( looking at the Jeep) left front headlight near the bottom . You must either cut a hole there in the plastic or remove the entire front bumper. The item is avalible at discount on eBay or from the dealer it costs $120

good luck

AnswerTry checking the radiator fan. It's likely that the motor has failed or the relay is bad. AnswerSound like your fan stopped working. Same happened with mine. It's a 2000 Grand Cherokee. OEM replacements are expensive $350.00 plus. Aftermarket is much cheaper $150.00 AnswerTry turning on the AC to see if the radiator fan comes on. It should.If the fan does not come on check the fuse on the wing in the engine compartment.If the fuse is OK turn on the AC and check that the motor has voltage to it at the motor wire conector at the fan. If there is no voltage here it is probably the relay, if you get voltage then its propbably the fan.

The relay is dificult to find, under the passenger head light on top of the wing - difficult to see let alone get to.

AnswerStrange situation with my 2000 GC. Fans spins fast if supplied directly with 12 volts. Seemed to be spinning, but slowly when connected to the wiring harness. Found that only 6.9 volts were getting to the fan. Not sure where to go from here. Fan is ok (?), relay works (or closes with some added resistance?), and logic seems to try to spin fan when hot, or with A/C on. Anybody know why less than 12 volts would be supplied? AnswerYou may want to check the viscous fan clutch as well as the electric fan as I have replaced 2 in 6 years on my 99 jgc (a lot of slow traffic here). An easy check, but not profesional, is to listen for the jet takeoff sound when you start off cold in the am, which should go away in a few seconds.
User Avatar

Wiki User

โˆ™ 2011-09-13 17:52:23
This answer is:
User Avatar

Add your answer:

Earn +5 pts
Q: What would cause a 1999 Jeep GC to overheat in traffic but be fine on the highway?
Write your answer...

Related Questions

What would make a 2002 Pontiac sunfire overheat?

A lack of water in your cooling system will cause your 2002 Pontiac Sunfire to overheat. A malfunctioning thermostat can also cause it to overheat.

What would cause a 1995 Ford Escort to overheat in stop and go traffic but not on the highway?

If it's overheating, then it might be several things like: low coolant level, improper coolant mixture, faulty fan on the radiator, or it's relay that controls the fan. Or maybe even the water pump is on it's way out.

Why would a Subaru Outback overheat?

You are not giving enough information to get a reasonable answer. It's like asking why it won't start. Any, and I mean any, detail would help. Are we talking about the engine cooling system? What are the symptoms that bring you to the conclusion it is overheating? Have you checked the coolant level? What year and size engine? Does it overheat only when stressing the engine, like climbing hills? Does it overheat only in traffic and okay on the highway? Does it overheat when the car is idling? Has the head gasket ever been replaced?

What would cause 95 S10 Blazer to overheat on the highway at 60 to 70 but not on city driving 40 to 50?

the thermostat probably went bad try to change it or take it out and see if it that helps.

What would cause a Kia Sephia to overheat?

Too high a temperature

Would blown head gaskets cause your vehicle to overheat as soon as you drive it?

it is possible for heat from combustion to cause an engine to overheat quickly depending on where the gasket is blown, but i would look for a lack of coolant circulation first. if your coolant is not getting out of the motor and into the radiator it will overheat very quickly.

What would cause a 1997 Saturn SC1 to overheat when sitting in traffic and not overheat if moving on open road?

Low coolant level, or the cooling fan(s) are not energizing due to a bad fan motor, sensor, or relay- maybe even a broken wire. Engine coolant temperature sensor will cause that everytime... more likely than anything else because it only does it when stuck in traffic or stop sign to stop sign and not on open road.

Why would the alternator over heat the car?

It will not cause the engine to overheat. You have another problem.

What would cause a 240 ford motor to overheat?

A stuck or incorrectly installed thermostat.

What would cause a car to overheat when idling?

The radiator cooling fan is most likely not working.

Would a bad clutch fan on a 1994 Mazda B3000 cause it to overheat?

Yes it could.

How many vehicles would cause traffic jam 12 miles long on a 6 lane traffic?

One car can cause it.

Would raising taxes on gasoline reduce automobile traffic in a nation highway be an example of a normative analysis?

No, it would be speculative analysis.

What would cause an 1989 Firebird to overheat?

A lot of things could be causing that. First did you check your coolant?

What would cause a 2002 Mazda B3000 to overheat for 10 seconds and then return to normal?

Bad thermostat

Does a engine have to overheat to damage head gaskets?

no the higher milage or higher rpms can cause the head bolts to stretch which would cause it to blow

What could cause the camshaft position sensor to completely melt in a 95 Acura Legend?

If you have had an extreme overheat in the past. This would most likely cause the censor to melt. Overheat to the point of the steering wheel locking up and the light coming on.

What would list a new cars rating as determined by the national highway traffic safety administration?

Monroney Sticker

What would cause an engine to overheat in a 99 Grand Am?

Hey Craig==The most common cause is the cooling fans are not operating correctly. Check them out. GoodluckJoe

What would cause a 1997 Dodge Intrepid to overheat if it is not the thermostat?

Try the rad. fan or the rad. fan relay

What would cause a Ford truck to overheat at high speeds?

low oil low radiatio flued or the thermistat

97 Dodge Intrepid sport- If oxygen heating sensor is bad would that cause car to overheat?


What would cause your Nissan to just shut off?

The overheat of the engine. You could find some information on Wikipedia.

Why does your car overheat after adding transmission fluid?

Your motor oil going bad would cause that. That is in the crankcase, not the transmission.

Can an overflow jug cause a car to overheat?

One situation that the overflow jug would cause an overheat condition would be if the hose and/or connectors were plugged up or blocked. NOTE: before disconnecting anything to do with the radiator, ensure the engine is COOL! The cooling system operates under significant pressure.