AC Cars & Trucks - Recent Questions, Troubleshooting & Support


Have you checked voltage and ground for blower motor? in the diagram, the top wire at blower motor is voltage. The purple wire, bottom wire from blower motor is ground. You can see blower fuse at the top, hot all the time. The blower motor on/off, different speeds are controlled on the ground circuit. You can take two wire connector loose from blower motor, use both ends of test lite at wiring connector terminals, turn on key, turn on hvac and blower controls, if the lite comes on, you have voltage and ground. If good voltage and ground with no blower action, suspect the blower motor. I couldn't post whole diagram and make it readable. The problem could be almost anywhere, with the wiring? I can only help with testing. good luck blower motor-undefined-undefined-0.jpg

AC Cars & Trucks • Answered Yesterday


engine coolant temp sensor-undefined-undefined-0.jpg The coolant temp sensor is #9 in the picture. How hot does it get in degrees F? Are the radiator fan/s running?

AC Cars & Trucks • Answered 3 days ago


manual hvac fuses-undefined-undefined-0.jpg These fuses are for manual hvac. Not only check the fuses, use a test light and check voltage at fuses. One fuse is hot all the time, the other two go hot with key on. Also, check ground at hvac unit, black wire, not shown in picture. good luck.

AC Cars & Trucks • Answered on Jun 18, 2021


Should show closed on anything under about 275

AC Cars & Trucks • Answered on Jun 05, 2021


Engine ... AC .... which one ... .

AC Cars & Trucks • Answered on May 24, 2021


You have actuators which direct the air in the heater/vent/AC system. My first cars used metal cables, then came along vacuum line control and most now use electric control actuators. They control things such as how much air from outside the car come inside, air flow to windshield/floor or dash, control mix of air for temperature adjustment. Your problem more than likely actuator issue. You can try google vehicle year, make, model temperature different from ac vent, when search you can change wording. If vehicle is older and used vacuum lines could have line leak, my 2000 GM van once had vacuum line laying on engine melted line and leaked. My 13 Chrysler, I have changed 2 actuators they are controlled by electric and started clicking when they went bad. DODGE DART, CHRYSLER 200 CAR BLOWS HOT ON DRIVER SIDE COLD ON PASSENGER OR COLD ON DRIVER SIDE - YouTube

AC Cars & Trucks • Answered on May 17, 2021


what is year--make--model? If asd relay, I guess dodge or chrysler vehicle. Make sure battery has a full charge and battery connections all good. Pull asd relay, use jumper wire on switch side of relay, that should send voltage to everything the asd relay controls, see if it will start and run? Also check cam and crank sensor signals. How long since a tune-up? Any applicable trouble codes?

AC Cars & Trucks • Answered on May 10, 2021


The AC stops ... the engine stops .... which I wonder.

AC Cars & Trucks • Answered on May 09, 2021


Probably something going on with the blower motor control Processor . Hooking a scan tool an checking for DTC'S - diagnostic trouble codes would be the first step in a diagnostic procedure for a problem like this . Auxiliary Blower Motor Control Processor The auxiliary blower motor control processor is an interface between the auxiliary HVAC control module and the rear blower motor. The auxiliary blower motor control processor monitors supply voltage and ground circuits to the rear blower motor. The auxiliary HVAC control module provides a pulse width modulation (PWM) signal to the control processor in order to command the blower motor speed. The auxiliary blower motor control processor uses the blower motor ground as a low side control to adjust the blower motor speed. The blower motor forces air to circulate within the vehicles interior. The vehicle operator determines the blower motors speed by placing the blower motor switch in a desired speed position or by selecting automatic operation. In manual operation, once a blower speed is selected, the blower speed remains constant, until a new speed is selected. In automatic operation, the HVAC control module will determine what blower speed is necessary in order to achieve or maintain a desired temperature. As the requested blower speed increases, the following conditions occur: • The HVAC control module increases the amount of time that the blower motor speed control circuit is modulated to ground. • The voltage and duty cycle, measured between the blower motor speed control circuit and ground, decrease. As the requested blower speed decreases, the following conditions occur: • The HVAC control module decreases the amount of time that the blower motor speed control circuit is modulated to ground. • The voltage and duty cycle, measured between the blower motor speed control circuit and ground, increase.

AC Cars & Trucks • Answered on May 01, 2021


ac condensers are in front of the radiator so anything that prevents the condenser from lifting up and out or out from the bottom could include bonnet release assembly and frame

AC Cars & Trucks • Answered on Apr 19, 2021


Make sure your low pressure limit switch is good and being made.

AC Cars & Trucks • Answered on Apr 05, 2021


Might not be the relay, there is a low side cutoff sensor on the return line. IF there is not enough Freon in it, the cutoff will open and the compressor wont start.

AC Cars & Trucks • Answered on Mar 14, 2021


DTC P0480: Cooling Fan Relay 1 Control Circuit Circuit/System Description The engine control module (ECM) commands the fans ON in high speed or low speed. In low speed, the fans are configured in series. In high speed, the fans are configured in parallel. In low speed operation, the ECM applies ground to the coil side of the low speed relay. Voltage is applied directly to the left cooling fan through the switch side of the low speed relay. The right fan is connected in series to the left fan through the de-energized series/parallel relay, which is the FAN CNTRL relay, so that both fans operate at low speed. In high speed operation, the ECM applies a ground to the coil side of the low speed relay, the series/parallel relay, and the high speed relay. Voltage is applied directly to the right cooling fan through the switch side of the high speed relay. The left cooling fan obtains voltage through the low speed relay and ground through the series/parallel relay. When the ECM is commanding a fan relay ON, the voltage of the control circuit should be low, near 0 volts. When the ECM is commanding a fan relay OFF, the voltage of the control circuit should be high, near battery voltage. If the ECM detects that the actual voltage of the relay control circuit is different than the expected voltage, DTC P0480 or P0481 will set and the affected ECM driver will be disabled. Conditions for Setting the DTC • An improper voltage level has been detected on the cooling fan relay control circuit. • The condition must be present for a minimum of 30 seconds. Circuit/System Testing Ignition OFF, disconnect the 3 cooling fan relays listed below. • FAN LO relay • FAN CNTRL relay • FAN HI relay Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 85 of each relay and ground. ? If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. Verify that a test lamp does not illuminate between the ignition circuit terminal 85 and the control circuit terminal 86 of each relay. ? If the test lamp illuminates, test the control circuit for a short to ground. If the circuit test normal, replace the ECM. Remove the test lamp. Ignition ON, command the affected relay ON using a scan tool. Verify the affected scan tool FC Relay Control Ckt. Short Volts Test Status Parameter is OK. • For the FAN LO relay, use the scan tool Fan Relay 1 command. • For the FAN CNTRL and FAN HI relays, use the scan tool Relay 2 and 3 command. ? If not the specified value, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM. Install a 3A fused jumper wire between the control circuit terminal 86 and the ignition circuit terminal 85. Command the affected relay ON with a scan tool. Verify the scan tool Relay Control Ckt Short Volts Test Status Parameter is Fault. ? If not the specified value, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM. If all circuits and the ECM test normal, replace the affected relay.

AC Cars & Trucks • Answered on Mar 08, 2021

Not finding what you are looking for?
AC Logo

Family Lines

1,661 questions posted

Ask a Question

Usually answered in minutes!

Popular Products

1953 AC 2 Litre
1953 AC 2 Litre

2 Questions

1961 AC Cobra
1961 AC Cobra

2 Questions

1965 AC 427
1965 AC 427

2 Questions

1952 AC 2-litre
1952 AC 2-litre

1 Questions

1963 AC Cobra
1963 AC Cobra

2 Questions

Top AC Experts

gbob59

Level 3 Expert

3063 Answers

David Harrelson
David Harrelson

Level 3 Expert

5456 Answers

Pierre Laplante

Level 3 Expert

2053 Answers

Are you an AC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...