1985/03/04 Caterpillar

Discontinued D.C. Generators Replaced By Alternators{1404,1405}

Usage:

All Caterpillar Equipment So Equipped

Generators with externally mounted voltage regulators are being discontinued. Alternators can be installed in place of the generators. This will require fabrication and/or modification of the mounting bracket. The wiring system will also need to be changed. The following chart lists the discontinued components and their new service replacements. The dimensions of the mounting bracket for each type of alternator are shown in Illustrations 1 through 14.

NOTE: All dimensions are in inches.

When a former generator is replaced by a new alternator, there must be:

1. Correct alignment of the alternator and crankshaft pulleys. When the mounting bracket is fabricated or modified, use 7T2071 Spacers as an aid in aligning the pulleys. The 7T2068 Adapter Group is also available as an aid in mounting 6T1193 Alternators.

2. Correct alternator rpm at high idle. The alternator should rotate at approximately 5,000 rpm at high idle. Use the following formula to determine which pulley diameter should be used on the alternator shaft to get the proper rpm:

3. Correct wiring system. Replacement alternators have a 2-wire system due to the built in voltage regulator. Some models being replaced have a 4-wire system. To connect the new 2-wire system, attach a No. 6 wire from the alternator output nut (B+) to the battery. Attach a No. 10 wire from the alternator ground screw (B-) to the vehicle frame. An optional third wire can be connected to the R terminal on the alternator to power an accessory. Unused wiring can be taped and left in the harness.

Components for 6 volt electrical systems are no longer being made and will not be supplied to the Caterpillar Parts Department. However these components will be available for parts service until supplies run out.

Be sure to install the fan supplied with the replacement alternator.

Illustration 1.