Here's an update on my "clicking" issue with my 87 300D. Stage 1: Clicking noises from behind glovebox occasionally after a cold start. Disappear after 5-10 minutes.
Stage 2: Clicking noises now occur after every single cold start, but still disappear after 5-10 minutes. Stage 3: Clicking noises now toggle the blower on and off every second or two. The recirculate light flashes rhythmically with the blower motor switching on and off. Symptoms disappear after 5-10 minutes and ACC operates normally. Stage 4: No clicking noises at cold start. ACC unit does nothing, but the blower motor fuse is OK. As the car warms up, hot air blows from the side and defrost vents. ACC unit does nothing to regulate temperature or air flow, which seems to increase with speed (blows REALLY hard and hot on the highway). Stage 5: One used aux water pump from Pick-n-pull and $5 later, all above symptoms are gone, ACC operates normally, and I can sleep at night. -Aaron 1987 300D 1987 300TD
