Wiper delay relay?

Looking for a bit of advice regarding intermittent wiper function on 1996 90 300Tdi.
Fast and slow speed wipers (up one and up two on the stalk) work fine and park correctly. One down on the stalk should be an intermittent wipe according to the handbook. However, pushing the stalk down gives a constant slow-speed wipe, just like one click up. I am guessing that the problem is with the intermittent relay, which is stuck 'on' rather than delaying the wiper. But I have read here that it could be the park switch on the motor causing the lack of intermittent wipe - could it be this, even though the wipers park perfectly in all switch positions? I'm starting with the relay first - can anyone tell me where it is? There are several behind the fuse box in front of the gear lever. Is it one of these, and if so which one? I thought I might ask before I start pulling them all out Thanks for any advice.

Just an update if this comes up in a search in future. The problem turned out to be the relay. I had to replace the wiper stalk as the washer was not working properly and it's the MoT next week. I thought I would replace the relay at the same time. New stalk made no difference to the intermittent wipe but the new relay cured it.

The relay is the second from left behind the fuses in front of the gear lever (1996 Tdi).