What should I do about my factory GM harness?

What should I do about my factory GM harness?

One of the most significant things an installer can do to speed the conversion process along and keep the headaches at bay is to have their factory GM harness simplified and modified. Novak has gotten this wiring process and PCM programming down to a science.

Where do I get the PCM wiring harness?

Typically, the conversion installer will get the factory engine harness from the donor vehicle. This will include every wire and connector between the PCM and the engine’s sensors (Oxygen, Throttle Position, Crank Position, etc.) and the active systems (coil triggers, injectors, IAC, etc.).

Is the GM Generation 3 + PCM harness compatible?

Pictured left is the extra heavy duty relay used in our rebuilds for radiator fan control. GM Generation 3+ PCM’s come in three major styles as follows: Make sure your PCM and harness are compatible, if they were not pulled from the same vehicle. Intermixing PCM’s and harness can yield unexpected results.

What should I do if my fan clutch is going bad?

Silicone fluid leaking from the fan clutch would cause this problem. When the engine is off, there are a few things you can do to check the fan clutch: Spin the fan. Electronic types might freewheel, but most fan clutches should spin with a little effort.

How does a torque limiting fan clutch work?

A torque-limiting fan clutch reacts to engine speed. A centrifugal valve opens to allow the flow of heavy silicone fluid, locking the fan blades to the pulley. At idle and low engine speeds, this fan clutch is fully engaged, gradually disengaging as engine speed increases.

How can you tell when a fan clutch is engaged?

You should be able to audibly detect when the fan clutch engages, with an accompanying rush of air. At idle, as engine temperature increases, a thermal fan clutch will engage at a certain temperature. Torque-limiting fan clutches will disengage at a certain engine speed. Alternatively, an optical tachometer can be used to measure fan speed.

How does a fan clutch work on a radiator?

A thermal fan clutch reacts to temperature of the air rushing over it from the radiator. As the radiator heats up, the air passing through it also heats up. This heats up a small bi-metallic coil in the face of the fan clutch, releasing an internal valve.