Tech Updates

Charging System Diagnosis: Start With the Alternator

Denso suggests that when a vehicle is brought in with a charging system complaint to first check alternator performance.

If an alternator test bench is available, follow the procedures found in the bench tester’s instruction manual to conduct an alternator performance test. This test will determine if the alternator’s output is within performance specifications.

If the output is within specifications during the bench test, resolve problems in the remainder of the vehicle’s charging circuit and other electrical circuits that may affect charging circuit performance. Refer to the vehicle manufacturer’s service manual for the proper procedures to follow to identify and correct charging circuit problems.

If the bench test results show the alternator output is out of specification, replace it. Follow the vehicle manufacturer’s recommended procedure for inspecting the remainder of the charging circuit and other electrical circuits that may affect charging circuit performance.

If the alternator you are testing has an internal regulator, and the bench test identified the regulator as defective, it may be possible to replace the internal regulator and return the alternator to service. If the regulator is replaced and the alternator returned to service, follow the vehicle manufacturer’s recommended procedure to inspect the remainder of the charging system and other electrical circuits that may affect charging circuit performance.

Fifth Wheel Cylinder Kit Installation

Use the following procedure when installing an air

actuated fifth wheel cylinder kit on Fontaine Ultra LT series fifth wheels:

Remove the fifth wheel from the mounting bracket. Fontaine advises cleaning the fifth wheel prior to installing the kit.

Place the fifth wheel in the upside down position making sure the wheel is placed on a suitable work surface.

Remove the pull handle spring from the fifth wheel (see Figure 1).

Install the exhaust valve into the air cylinder (as shown in Figure 2). Make sure the exhaust valve is oriented properly.

Install the new air cylinder, making sure it is oriented properly (see Figure 3).

Reinstall the fifth wheel back on the mounting brackets.

Insert the air supply line into the quick disconnect on the exhaust valve.

Open and close the fifth wheel using the air cylinder to ensure proper function.

Tilt the fifth wheel forward to ensure that the cylinder and air supply line does not interfere with another component.

Figure 1

Figure 2

Figure 3