Temp guage false reading - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > ZJ Grand Cherokee Forum > Temp guage false reading

ECGS Black Friday Sale!!6th Annual, Beat Your Wife to the Credit Card Sale!50 in light bar /A pillar mount less than 500 at JeepHut.c

Reply
Unread 05-27-2006, 05:50 PM   #1
mldcaptain
Registered User
 
Join Date: Jun 2004
Posts: 4
Temp guage false reading

I'm goin nuts here, hopefully someone can shed some light on this for me. When I start my 98 GC, the temperature guage reads as far to the right as it can go even thought the vehicle has been off for hours. Also, my auto headlights turn on in the sunlight. What the hell!?

Anyone got any ideas?

mldcaptain is offline   Reply With Quote Quick reply to this message
Unread 05-27-2006, 07:37 PM   #2
Test
Registered User
2007 WK 
 
Join Date: Oct 2004
Location: Grand Forks, ND
Posts: 381
Probably the coolant sensor. As for the headlights, it's probably the sensor located on the top of the dashboard. What year and vehicle?
Test is offline   Reply With Quote Quick reply to this message
Unread 05-27-2006, 08:12 PM   #3
mldcaptain
Registered User
 
Join Date: Jun 2004
Posts: 4
1998 grand cherokee laredo.
V8
5.2l I think
mldcaptain is offline   Reply With Quote Quick reply to this message
Unread 05-28-2006, 07:59 AM   #4
greasefingers
Registered User
1994 ZJ 
 
Join Date: Sep 2003
Location: Northern VA, USA, NJ
Posts: 8,237
There are two coolant temp gauges. One on the thermostat housing for the ECU and another one for the dashboard gauge reading. Your gage sensor is either broke or more likely not plugged in. Check the electrical connector at the top of the gage. Also with the connector off measure the resistance across the gage. It should measure around 13,000 ohms at 70 F. When a gage pegs all the way to the right, the circuit has an Open. (meaning most of the times that a wire is broke or it is simply not plugged in)
__________________
Cheers Steve

94 Black Laredo 4-Liter with QuadraTrac (42RE trans & NP249 TC) 200,000 + miles purchased new

88 Cherokee 2-door with 5speed manual 139K miles(deceased) purchased new
greasefingers is offline   Reply With Quote Quick reply to this message
Unread 05-28-2006, 10:45 AM   #5
mldcaptain
Registered User
 
Join Date: Jun 2004
Posts: 4
1-where is the gage sensor and what does it look like?
2-I'm assuming I have to take my dash apart to get to the gage and the gage sensor. Is this correct?
mldcaptain is offline   Reply With Quote Quick reply to this message
Unread 05-28-2006, 11:00 AM   #6
greasefingers
Registered User
1994 ZJ 
 
Join Date: Sep 2003
Location: Northern VA, USA, NJ
Posts: 8,237
I do not believe the gage is the problem, but the sender unit/probe that will be mounted to the engine somewhere. I do not have your engine so I cannot say where exactly it is.
__________________
Cheers Steve

94 Black Laredo 4-Liter with QuadraTrac (42RE trans & NP249 TC) 200,000 + miles purchased new

88 Cherokee 2-door with 5speed manual 139K miles(deceased) purchased new
greasefingers is offline   Reply With Quote Quick reply to this message
Unread 05-28-2006, 11:10 AM   #7
greasefingers
Registered User
1994 ZJ 
 
Join Date: Sep 2003
Location: Northern VA, USA, NJ
Posts: 8,237
I do not know enough about the v8 engine. You might have one coolant temp sensor, that doubles as the sender for the dash board gage and the Input to the PCM/ECU? So I would start by examining the one sensor that I know of on the V*, which is located between the A/C compressor and the alternator. Make sure that the electrical connection is sound.
__________________
Cheers Steve

94 Black Laredo 4-Liter with QuadraTrac (42RE trans & NP249 TC) 200,000 + miles purchased new

88 Cherokee 2-door with 5speed manual 139K miles(deceased) purchased new
greasefingers is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.