I have an 1984 Cadillac Fleetwood.
A read the trouble codes.
The is code 15.
Open coolant sensor circuit.
In the diagnostic test there is -40 celsius from the CTS.
And i haven't got any HEAT.
The blower works, but the air is cold.
Maybe i haven't got heating because the CTS is bad?
Where is the coolant temp sensor in the car?
The cold air goes from the defrost intake.
Both hoses are hot at the heater core.
Heater valve is OK.
How can I see the AIR MIX DOOR or MODE DOOR problem???
How can I diagnose this problem?
In heater mode why cold air comes like defrost mode?
CTS is near the thermost housing on the intake manifold, 2 wire connector.
If both hoses are hot the problem is usually in the temp door controls, this
system is automatically controlled by thermistaors and a dial rheostat,
sending a signal to a programmer which in turn moves the temp door based on
in car temps, outside temp and dial setting, it is underneath/ behind the
Check all the electrical connections from the sensor back. Check wiring
for; bad terminal connections/bad wire/faulty mating of the cts
terminals/connectors. Once you are sure of the wiring, then there is a
long diagnostic list to try. It starts with disconnecting the cts and
putting a jumper wire between the terminals in the wire harness. If the
parameter value then is: -40 to -35, there is one ladder to follow. If
the value is -34 to 151 there is different ladder to follow.
One of the electrical inputs the air-mix valve is adjusted by is, the
When/if the cts value is wrong, as seen by the computer, it then uses
the mat sensor value to operate.
I'm willing to help, so read the values with the jumper-wire in place
and post them.
Is your email addy right? I may go to my pc instead of this terminal.
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