Noticed that the heater fan on my 67 Delta turns faster when I rev the engine or am at highway speed. Is this normal for older cars?

Thanks

 

Most likely just caused by lower alternator output at idle. My Toyota does this.

 

It's normal, just as your headlights will dim a bit at idle!

 

All cars' alternators put out less power at idle, but do check to make sure the alt is doing is thing - it is easy!
Check your battery voltage with engine idling (700RPM), lights and heater on high. Voltage should be 12.7V or above. Anything lower would indicate a possible problem.

 

Cool thanks