When I bought my 90 HB Si I noticed that my cooling fan had been hardwired in so that it ran all the time...this morning it was unusually warm for January (13C) and I glanced at my gauges and couldn't believe my eyes when my temperature gauge was almost in the red...with the fan running constant! I couldn't figure out what was going on...the only thing that I'd done different this morning was not turn on the heater...so I tried that...
I opened my windows and turned on the heater full blast taking the air in from over the engine...within a minute my gauge was coming back down and levelled off (with the occasional spike) over the next five minutes.

WTF? Help? Temperature when it comes to my engine is all new to me...so go easy...

Jason