I have a 99 TL, runs great, no problems, except the air from the heater is turning cold suddenly while driving. I can get it warm again by turning temp right up. No connection to A/C on or off, replaced water pump, heat servo motors working fine. Heat will work great while parked, idling, then upon acceleration turns cold sometimes. No connection between problem and outside temp.Anybody got a thought for me?
Thanks for any help.