ATC CONNECT – Parts cross references and look-up made easy
We continue to field and are happy to answer questions about this great new tool. Information on the top 2 questions can be found right here..How to Get Access and How To Use. The other most frequently asked question is about on-hand inventory. This update is completed overnight and ATC CONNECT displays the current inventory levels at the start of the day. As orders are placed and stock is depleted, if you need it, call or email us to order it. Remember the primary function of ATC CONNECT is parts cross reference and look up.
Parts Ordering via email
We look forward to hearing from you, but we know at times you simply want to “place an order” vs waiting in a queue as we assist others with cross referencing, product info and or custom application needs. We hope you appreciate that we can’t staff for unknown peaks and in an effort to better serve you, we introduce email@example.com.
Simply provide all necessary details… part numbers, quantity, pickup location, ship to location, purchase order # etc and we’ll acknowledge and process your request as soon as possible.
Call us toll free at 1-800-295-4156, our Customer Service Representatives will be happy to assist you.
Before you pull the A/C compressor from a heavy-duty vehicle, take these steps to confirm that it really needs replacing:
1. Is The Compressor Rotation Smooth?
With the vehicle off, turn the compressor shaft with a 14-mm socket. If you feel grinding or hanging as you rotate the shaft, it’s probably due to broken components within the compressor. If the rotation is smooth, move on to Step 2.
2. Is The Coil Getting More Than 11.5 Volts?
Take a reading with the engine running and the clutch engaged. If there’s insufficient voltage, get to work on that. Otherwise, move on to Step 3.
3. Is The Coil Resistance Between 2.8 And 4.4 Ohms?
Any resistance outside this range will prevent the clutch from engaging or will cause used circuits to open. If the answer is yes, continue to Step 4.
4. Is The Compressor Able To Produce 350 Psig Or More?
If not, leave the compressor where it is. The system may have a low refrigerant charge because of a leak that needs repair, or a high-side blockage that limits refrigerant flow to the compressor.
Tech Tips from Red Dot
” We see lots of compressors that are returned fully functional and therefore not warrantable.
Get the diagnosis right. Perform a simple compressor function check before you pull the component from the vehicle.”
Tech Tips from Red Dot
1. Inspect Electrical Connections
As you perform a visual inspection under the hood (cab) and/or at the rooftop condenser, take a moment to check all electrical connections both visually and by feel. Make sure all leads and wires are properly supported and securely connected, and that there’s no corrosion or grime on the leads or connectors.
2. Check Electrical Current Flow and Device Functions
Perform the following steps to check current flow and electrical device functions:
- Turn on the ignition.
- Turn on the A/C system. This will power the thermostat and clutch. If it does not come on, use the A/C mode switch to check the leads to the switch. You should hear a “click” from the thermostat and hear the clutch drive plate “snap” against the clutch pulley.
- Check fuses. If all the connections are clean and tight and there’s still a failure, check the fuses in-cab as well as in-line.
- Check A/C clutch engagement. Since you can’t see and may not hear the clutch engage, get out and look at the clutch. If it’s engaged, you will see that the drive plate is against the pulley and not slightly spaced from it. If you aren’t sure the clutch is engaged, look for the lead wire connector near the clutch. Break and close that connection. The clutch will disengage and engage again.
- Test blower speed operation. Some systems have a common switch that turns on the air conditioner and powers the blower motor. Test blower speed operation by adjusting this or the separate blower control switch. Feeling the air flow from the ducts or note blower sound (speed) changes.
- Inspect roof-mounted condensers. Don’t forget to inspect roof-mounted condensers and A/C units for dirt and debris. Be sure the condenser fan(s) are working properly and all parts and electrical connections are securely fastened. The roof-mounted condenser fans may come on when the system is turned on. Like the thermostat and most clutches, the normal on-off cycling action can not be observed until the engine is running with the A/C system on.
Once your visual inspection is complete, talk to a qualified A/C technician about what you found. Your troubleshooting efforts will be rewarded with a speedier repair and perhaps a lower repair bill.
An electrical resistor whose resistance is greatly reduced by heating, used for measurement and control. Thermistors, derived from the term THERMaIly sensitive reslSTORS, are a very accurate and cost- effective sensor for measuring temperature.
Your HVAC Thermistor can be replaced with #1400K for Quicker Installation and Less Hassle!
Our Kit contains “First Fit OE Products” for longer life solutions to today’s A/C problems.
Check out the video courtsey of MEI here ….
A relatively new feature in the heavy duty industry, the cabin air filter is often overlooked in regular vehicle maintenance. That’s unfortunate because the cabin air filter is just as important to the passengers as the engine air filter is to the vehicle and a likely cause of “A/C Not Blowing Cold“. A cabin filter processes the air that enters the passenger compartment via the vehicle’s heating and air conditioning system, increasing passenger comfort by trapping particulates, pollen, and other irritants.
For people with allergies and other sensitivities to airborne agents, the cabin filter represents a significant advance. Replacing the cabin air filter at the recommended interval, or sooner especially in areas of high particulate, allows the A/C system to run at optimal efficiency and passengers to breathe cleaner, fresher air, which makes any journey more enjoyable – Courtesy of Denso Corporation
Remember to always use caution when performing preventative system maintenance, as ambient conditions (heat load) will increase refrigerant hose temperatures and don’t forget having the right quality parts on hand makes all the difference. See How To and Which Components to Inspect and watch this video to learn more about Basic A/C Troubleshooting.
Quick Heater Service Tip from Reddot
- When the status is “heater fan doesn’t work,” check the ground connection for rust, paint, grime, or some other obstruction at the terminus.
- If the motor doesn’t have a ground wire, its mount serves as a ground connection. Make sure nothing impedes the mount’s ground path.
- Use a multimeter to make sure you’re getting full voltage to the motor. Once you know the voltage is adequate, you can then look for worn brushes, dirty squirrel-cage fans, damaged fan blades, and other more typical motor problems.