CONTROL VALVE GROUP 4J3321 - Caterpillar

Installation
The converter assembly should be mounted in a cool, dry place, preferably inside the cab. It should not be mounted in the engine compartment or where it will get wet.
The preferred mounting location is where there is free movement of air across the converter assembly, and where it is unlikely that a coat, hat or other obstruction will be hung or laid on the converter assembly.
Special Instruction Form SMHS7749 gives information concerning installation and connection of the converter assembly. The reference to a 10A fuse in this Instruction has misled some readers. The fuse is only to protect the wire between the fuse and the converter assembly. The converter assembly itself does not require a fuse. It is not true, as the Special Instruction states, that using a larger fuse will damage the converter assembly. The recommendation of a 10A fuse does not mean that the converter assembly will produce 10 Amps.
There are two cables coming from the converter assembly. One has a two-pin Sure-Seal Connector, and the other has a three-pin Sure Seal Connector. The two-pin connector is the 24V input, and the three-pin connector is the 12V output (one pin is not used). Use the 6V3000 Sure-Seal Repair kit to make mating connectors as required.
Two-Way Radio Applications
There are three general types of two-way radio equipment that might be used with the 9G6981 Converter Assembly: 1. CB Transceivers.2. Low-power business-band tranceivers (up to 20 Watts RF output).3. High-power business-band transceivers (over 20 Watts RF output).
Any legal CB transceiver can be powered with the 9G6981 Converter Assembly.
Low-power business-band transceivers can also be powered by the 9G6981 Converter Assembly, provided the input current requirement in the transmit mode is less than 4 to 5 Amps. Check the radio manual, or measure the current while actually transmitting. To measure the current accurately, use a 6V3030 or 6V7070 Meter on the 10A Scale, or the 6V4910 Clamp-on Ammeter. Connect the transceiver to a power supply and transmit into a 50-Ohm dummy load or into a correct antenna located at least six feet away from the meter. If a battery is used as the power supply, be sure the voltage stays above 12V during the test; if the supply voltage is slightly low, the current draw will be affected. Never transmit without an antenna or dummy load connected to the transceiver.
When checking the transmitter current draw specs, do not confuse the input current requirement given with the RF output power (given in watts). Be sure to use the input current requirement for the transmit mode (sometimes abreviated 'XMIT" in the radio literature), because the current requirement in the receive mode (RCVE) will be much less. In general, the input current requirement of a solid-state transceiver can be estimated by:
This gives an approximation only. Some transceivers are more or less efficient and may vary considerably from the formula given.
High-powered 12V business-band transceivers, in general, cannot be powered by one 9G6981 Converter Assembly unless they are detuned. Detuning involves intentional misadjustment of the coupling