Try this for a problem

Right.  Fitted a new (2nd hand) wiper motor today as my old one was only working on full speed setting.  It didn't work at all but what was happening when i flicked the wipers on was the fuel p/p cutting in.

When ever i moved to a different setting, including off, the relay closed and the pump fired up.  Even on intermittent, when the wiper relay activated the motor the pump started up again.

Fuses 6 & 9 were blown so i replaced them with fuses 7 & 8 just to check this wasn't related to wipers (just as they were the same capacity).  With '6' in, my hazards were operable (previously not, just brought the dash light on permanently).

Motor still not working.  Tried old motor which suddenly works completely, parking and all.  But, when wipers are turned on or when intermittent cycle kicks in - the fuel pump cuts in.

I accidentally shorted fuse terminals 6 & 7 with screwdriver as i was taking a fuse out and the fuel pump relay closed and pump cut in.

I thought the fully functioning wipers might relate to fuse 9 being replaced so i took it out but they were still going strong.  As was the fuel pump (this runs the sequence via the relay each time, doesn't stay permanently on).

Hazards only work with fuse 6 in.  The hazard switch bulb and the hazard dash bulb flash simultaneuosly with ignition off but with it on they flash alternately.

So much fun  

What's going on? It can't be down to relays can it?  It must be wired up wrong?  The fuse box looks good physically, i've heard they can crack, i don't know what it's like inside but i hope the box isn't to blame.

What are the chances it's the box?  What are the chances it's purely down to wiring?

Just read the fuse box thread and it shows the interior light being fuse 6.  Can't remember what '9' is but it's nothing to do with wipers or hazards etc.  What's the connection? No pun intended….

         

Its not unknown for the fuse box to get wet via water following the cables/wires/loom thru the bulkhead above it. It then starts to play up with wierd and wonderful symptoms. Does it look like its wet or been wet (water stains, rust marks on relays, damp carpet etc)

Also check all the earths, under bonnet and the 'rose' next to the fuse box.

Well the other day, the fuel pump relay started clicking/buzzing away like mad eventually cutting the engine out.  I had a look and saw a couple of drops of water but since then i haven't seen any.  There doesn't seem to be a any signs of constant ingress except for on the drivers side.  There is, however, corrosion on some of the female connections round the back of the fusebox.

Can it be sprayed with anything to drive moisture out? Servisol or something like that?

It's an early torpedo type by the way.

Well looks like you've found the possible source of your problem. Take lots of pics of what goes where and remove the fuse box and dry it out and clean up the connectors. Fix any leaks and try it all plugged back in.

If that fails I'd try to find a replacement pref new old stock.