PIN-FORCING 5P8749 - Caterpillar

The current requirement for both the 12V Heater and 24V Heater is the same at 90 to 100 amperes. Do not use wire that is smaller than #4. The 24V Heater produces approximately 2000 Watts heat output; the 12V Heater produces approximately 1000 Watts.Installation Tips
*Power wire (cable) to heater must have extra length to allow for engine movement in the soft engine mounts. Wiring must not rub. Use rubber insulated clips to secure wires.*Terminals for power cables should be soldered, in addition to crimped.*Power wire from Battery POS (+) connection for machines with "main disconnect" switch must be on the "switched "side of the main disconnect switch, so that the battery power to the heater relay is off whenever the main disconnect switch is off. This can be accomplished by connecting power wire (cable) to the same location as either end of the POS starter cable, at the disconnect switch or at the starter.*Be certain inlet manifold cover, air inlet elbow, gaskets, and hoses are assembled securely to avoid possibility of dirt entry.*It may be necessary to loosen the turbocharger compressor housing and rotate the housing slightly to align the housing with the new air inlet elbow. It is NOT necessary to remove the turbocharger from the engine. Be sure to re-tighten the turbocharger compressor housing.*Use rubber boots to insulate all wiring connections to avoid short circuits.*Be sure to use heater assembly, relay, and indicator lamp of correct voltage.*Pushbutton switch to control relay should be wired so that power is only available to the pushbutton switch when the ignition keyswitch is "ON". AIH System should not be able to turn on AIH when key switch used for starting is "OFF".*Indicator lamp should be located in or near instrument panel so that operator can see it easily while holding pushbutton for preheat. Indicator lamp should be labeled, such as "Air Heater" or "Inlet Heater", and should have appropriate instructions, such as "For cold weather use. Do not exceed 30 seconds preheat before cranking engine ". Indicator lamp should be wired in parallel with the heater relay (not in series), so that pushbutton activates the indicator lamp in parallel with the heater relay. If preferred, the indicator lamp can be wired to the switched side of the power relay, so that indicator lamp will work only if power relay is functional and provides power to the heater. This would require a wire from the switched side of the relay to the indicator lamp at the instrument panel.*If equipped with either starting aid. The AIH System may be used with an ether injection system only if the ether is injected directly into the inlet manifold, so that the ether does not flow across the heater element. Do not use ether that is manually sprayed into the air system from a spray can when using the AIH System, as this ether would have to flow over the hot AIH element. If an existing Ether Aid is plumbed into the air cleaner