Trouble Shooting; No Green "On" Indicator On, Thermostat In Any Functional Position - Intellitec ELECTROINC CLIMATE CONTROL Service Manual

ELECTRONIC CLIMATE CONTROL
If the following problems occur, proceed with their analysis in the order in which the steps are listed.
I.

No green "ON" indicator on, Thermostat in any functional position.

A. Slide the test switch on the Control Module towards J2. Front compressor and high fan should
turn on. If not:
1. Make sure that the power connector (PC1A) is plugged into J1 on the control module.
Make sure that the pigtail keying matches connector keying.
2. Check the 5A fuse in the distribution panel for Control Module power.
3. Check for +12VDC at pin 4 of J1 on control module and ground at pin 6.
B. Check the IPX SIG and IPX GND connections to the ECC Thermostat. If OK:
1. Measure the DC voltage between the IPX SIG and IPX GND lugs and measure the voltage
between pins 7 and 8 of J1 on the Control Module. The voltage should read greater than
4 VDC and be the same at both locations. If the voltage is OK at both locations replace the
Thermostat. If not:
(a) Check the wiring.
(b) Replace the Control.
II.
"ON" indicator is on but the position of the set point temperature controls on the ECC
Thermostat have no effect on heat and cool functions on either front or rear systems. In
the HEAT mode the furnace stays on all the time. In the COOL modes the fan comes on
but the A/C compressor never comes on.
A. Check the installation of the Temp probes. The front probe should be connected to J1 and the
rear probe to J4 on the Thermostat. If OK, measure the resistance of the Temp Probe at the
connector. Resistance should be 7,500 to 15,000 Ohms. If not:
1. Replace Temp Probe.
2. Replace ECC Thermostat.
INTELLITEC

Trouble Shooting

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131 EISENHOWER LANE NORTH
LOMBARD, ILLINOIS 60148-5413
630-268-0010 / 1-800-251-2408
53-22130A100