UK Car Repair: range rover classic heater, heater fan, differance

Question
QUESTION: hi william, can you help- i have a 1990 range rover 3.9 vogue classic non air con. and my cabin heater fan will not work till the engine has been running for about 10 mins, then works perfectly on all speeds. doesnt make any differance if i tap the dash, ive just gotta wait for it. cheers garry

ANSWER: This may be normal, many systems incorporate a heat switch which prevents the system from working until the water reaches a basic temperature. Is it hot when it does work?

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QUESTION: cheers for your prompt reply, but the heater does get hot after a few mins. but after driving when the engine is hot if i stop to go in a shop when i get in its another 10 mins before the fan works again

Answer
It is a fairly simple system but it does have a load relay which cuts off the fans under high load conditions, I would guess that this relay is where the fault is, you would have to by pass it!~ Also does switching it to recirculation mode have any affecdt?