Intermittent Wipers on 1990, 90 Truck Cab

I decided in my ultimate wisdom to change the wiper switch on my 1990 Truck Cab to one with an intermittent option on it (PRC7370) as fitted to later models, I also have the new relay AMR2341 that is required.

My problem is I can't find the original relay that I need to replace There is 4 relays in the behind the fuse box (was the glass fuse type until I changed it), one for the indicators plus 3 others, I tried removing each relay in turn to see which is the correct one and the wipers and washers still worked with them removed.

I can't find any other relays fitted anywhere so any help would be most appreciated.

You may not have a wiper relay, I think some of the early models just switch the wipers directly.

Just had a quick look at the '87 onwards wiring diagram. No sign of a wiper relay. You can still fit one, just a bit more work.

zeaphod said:

Just had a quick look at the '87 onwards wiring diagram. No sign of a wiper relay. You can still fit one, just a bit more work.

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Look like it is make a wiring loom time then.

Many thanks for your help

No wiper relay fitted as standard and you could make a loom from scratch (I did) but then Autosparks introduced the correct item so I bought one from them (I like to keep everything as standard as possible and having the correct moulded plugs on the end was a big plus point).

My 93 was wired for the adjustable relay, mates 87 was not.

Litch said:

No wiper relay fitted as standard and you could make a loom from scratch (I did) but then Autosparks introduced the correct item so I bought one from them (I like to keep everything as standard as possible and having the correct moulded plugs on the end was a big plus point).

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Yes I have seen these, does one end plug in to the old harness and the other to the new wiper switch and pop in the relay and away you go?

ivancrx said:

..1990 Truck Cab to one with an intermittent option on it (PRC7370) as fitted to later models,...I can't find any other relays fitted anywhere so any help would be most appreciated.

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They will not be there as the intermittent wipers had a different loom, with the relay.
Ermm. Try a look up - there are some threads on this issue here. Seem to remember some VW thing so you can adjust the time between wipes??
Ah well, will see if I can remember in the next hour or so - if not then sorry. Off to a pub quiz and a pint

ivancrx said:

Yes I have seen these, does one end plug in to the old harness and the other to the new wiper switch and pop in the relay and away you go?

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Yes, as simple as that. Buy the loom, relay and new stalk (you need the intermediate setting remember) and it all fits together with the new harness plugging into the existing connector. Mine is a 1986 so uses the rubber moulded connector blocks.
The timer relay is usually fitted adjacent to the fuse-box I believe but it is awkward to thread the moulded plug of the harness behind the lower dash so I initially fitted the relay behind the instrument console (coiling up the excess harness) with the intention of moving it when I had the dash out (to have the bulkhead galvanised) but to be perfectly honest I am quite happy with it there so I re-fitted it in the same place after the rebuild.