Expert: Roland Finston - 7/21/2011

Question
QUESTION: I have a 96 Chyrsler Town & Country LXi, V-6 3.8 ltr, The temp gauge in the "dash" reads HOT when we first start the car at room temp. After we start the car "cold" it slowly comes down (not up) to mid temp and stays there. The Eletric Cooling fans on(radiator) come one and off with temp rise and a/c on! The ECS coolant sensor resistance seems in spec, bench tested, spec from manual 8000 ohms at room temp 1000 ohms at 200 deg f. I pulled back wire harness except for last foot at to PCM no "outside" problems noted. I tried pulling wire off ECS stays HOT on gauge and grounding positive only makes a little worse (I read another question) Gauge doesn't swing all the way. Power at plug is 5 vdc with + on brown wire. The gauge reads cold when the key is off.
Do you have any suggestions should I replace DASH Temp Gauge?
Any more wire tests? Note I tried getting mid point plug at engine apart - no way as it's external lock tab broke just
trying to open no way do to age will crack.  Gary

ANSWER: Hi Gary,
I have the '95 and '98 manuals and will be getting a '97 shortly. Let me tell you about doing a cluster self-diagnostic test from the '95 manual and we'll see what happens:
Press and hold the trip and trip reset buttons
Turn the ignition switch to the 'run' position, release the buttons
'chec' should appear in the odometer window
Press the US/met button and watch for 'code' to appear in the odometer window, then release the button. Then watch for three-digit code numbers to appear. Tell me what they are and we'll go on from there.
You can replace the dash temp gauge, but let us see what happens with the test.  Once the gauge reads half, do you notice it to change at all as you are driving?
Roland
Roland
r(s) to appear in the odometer window


---------- FOLLOW-UP ----------

QUESTION: Roland
Well insteresting - The problem did not go away still reads hot.
Reset test went ok during "check one" gauges went from 0 or cold to max. etc.
I tried to get most numbers as they went thru:
999
check o
trip888888
check 1 (all gauges cold to hot, 0 to max, etc)
trip 7777777
check 2 tesed milage window
check 3 tested Trans Position window - park etc.

But after check done gauge still reads Hot in Run.

Once the gauge reads half it does seem to modulate barely as fans kick on
like when fans come on. Seems like it responed more in the past??
what do you think?
thanks Gary

Answer
I would continue to observe it to see if it ever seems to be misleading you when you have a reason to believe for example that it reading too optomistically (saying it is cooler than things really are). False hot reading, particularly if predicatable, is something you can probably live with.