[Robert Ferguson]

Has anyone installed heater fan relays? They make quite an improvement on headlight system thought it would improve heater operation, or not.

 

[Tifosi]

Improve heater operation how?
The fan spins at the right speed, or it does not spin at the right speed due to corrosion or wiring issues, or it doesn't spin at all due to same.

Hitting it with a relay isn't really going to change that and may even create special little headaches like trying to work out how to get the speed selection to work right. (well, a relay on each circut would cure that)

If the intent is to get the motor to spin faster via more voltage, you'll likely get better results outright installing a new motor or a really good cleaning and lubing of the unit you have now.

It may seem kinda random, but actually calibrating the duct controls and syncronizing the duct flaps can go a long way toward improving heat onnaconna it ensures that the warmed air can get out of the box efficiently.

 

[Inner Circle]

actually calibrating the duct controls and syncronizing the duct flaps can go a long way toward improving heat onnaconna it ensures that the warmed air can get out of the box efficiently.

Or just get a Duetto or a Spider Junior (with Duetto console): then if you want the air to get out of the box, you just open the little door. If you don't want it, the you close it