Question about 1999 GMC Yukon

1 Answer

99 yukon temp gauge never warms up past 150-160. runs cold

Had the fan and radiator checked out, no problems found, had a new thermostat put in. that didn't help. i am used to gm's running closer to 210 or right under this is runnung alot lower. also rear defrost doesn't work. push the button and it clicks and lights up, but never melts anything. it's on the rear tailgate model. can't find any loose wires or damaged grids. any ideas?

Posted by on

1 Answer

  • Level 1:

    An expert who has achieved level 1.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 5 Answers

First test your coolant with a thermometer when it gets to full hot. Don't get scalded with the hot fluid.
if it is hot enough maybe the water temperature sensor is faulty. If the sensor is good then try putting the thermostat in a pot of water and with a thermometer test when it opens. sometimes even a new one is not accurate.
To test your rear window defroster,check your fuse, if good follow the circuit with a voltmeter. Wireing diagrams are in the Haynes manual.

Posted on Jan 06, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Temp/gauge not reaching normal working temp-richer


the first thing to check is to feel if the radiator is hot, if the radiator feels hot and the engine is also hot the coolant is circulating ok then the problem is more than likely electrical, the temp gauge gets its signal from the engine control module the coolant temp sensor sends coolant temp signal to engine control module for engine managment purposes then passes it to instument pack/gauge, if the sensor was at fault you would have engine running problems also,with poss fault codes logged, if the engine and rad are cold/only warm after the engine has been run for 15 mins or so it sounds like the thermostat is stuck open but you have changed that. i have had faulty new ones in the past and have had to test them in a pan of boiling water, hope this is some help to you.

Apr 02, 2015 | 2006 Jaguar X-Type 2.0

2 Answers

I have a 02 Grand caravan that has new radiator, termostat, one new fan. the temp gauge goes up to max hot the drops right back down in seconds. what could be the problem?


it could be you have an air lock in the cooling system
remove the rad cap from the rad, start the engine and let it run until the coolant drops (add to fill it back up) or until the coolant boils out of the rad spout.

maybe pull the heat sensor. -replace it OR clean it off, reinstall it.

Mar 12, 2015 | 2002 Dodge Grand Caravan

1 Answer

99 continental temp gauge not rising


Usually a sign of a faulty thermostat or temp gauge sending unit.
If the engine really is not reaching normal temp you would be burning more fuel.
Assuming the radiator is full of coolant, you could test the sending unit for the gauge, but my money is on a new thermostat.

Jan 22, 2013 | Lincoln Continental Cars & Trucks

5 Answers

2001 Ford Taurus running hot


First thing to check when the engine is cold is that if there is enough antifreeze in the radiator and after you run the engine for about 5/10 minuter check both the rad hoses to see if they are both at the same temperature, if the return hose which is the bottom one is cold then replace the thermostat. If both hoses are hot or same temp then make sure the radiator fan comes on?

Jan 08, 2013 | 2001 Ford Taurus

1 Answer

Hi: I read your answer to the problem with the 1999 Mercury Mistique temperature gauge. I'm having a similar problem. My temperature gauge is broken in the cold position. And, as far as I can tell,...


Very correct the ECT is a 2 wire thermistor,when coolant temp increases, the resistance andsignal voltage decrease,If you disconnect the sensor the fan goes on, you just trouble shooted the vehicle cooling fan switch, If anything the signal to the gauge itself may be non-op and not getting to the indicator, try this with vehicle at warm up temperature if you turn the A/C does the fan turn on.it should if it doesnt the power juction box (fuse and relay in engine compartment should be checked, for any opeen fuses, By the way the guage information is from the PCM

May 04, 2011 | Mercury Mystique Cars & Trucks

1 Answer

No heat. has a new thermostat. engine stays cold .


need to check to see if radiator is circulation the water . hose good make sure their no soft an sucking shut especaily the bottom hose . you can get a temp gauge take radiator cap off ,let warm up til thermostat opens put gauge in radiator see what temp. is . (wife got meat or candy temp gauge this will work) last it could be heater core bad.

Nov 02, 2010 | 1995 Mercury Grand Marquis

1 Answer

Intermitant temperature


Check to make sure your thermostat works right by monitoring the warming up of your engine. With a completely cold engine, start and run the engine for a few minutes, then put your hand on the top radiator hose to monitor if and when it gets warm as the thermostat opens more and more and note the gauge reading( if it works) the top radiator hose should be unbearably hot within 5-8 minutes. If the therm. opens right it should close right aswell, staying open a little while eventhough the radiator may have cooled may be what you are experiencing causing the rapid cooling and is nothing to worry about. The Hose should not get warm very soon after starting the engine. Regarding you gauge, lets take one step at a time, verify proper op. or the therm.

Jan 20, 2009 | 1986 Toyota 4Runner

Not finding what you are looking for?
1999 GMC Yukon Logo

234 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts

yadayada
yadayada

Level 3 Expert

60769 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

21949 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

6811 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...