Fiesta Mk4 Mk5 Rear Wiper - A fix!

Soldato
Joined
19 Jan 2003
Posts
17,542
Location
Bristol, UK
Evening all,

Rear wiper faults are common place on the older Fiestas.

The wiper on my GF's Fiesta has been intermittently working/broken for a while but recently hasn't worked at all.

After checking relevant points for 12v and continuity I moved on to the motor itself.

I removed the wiper motor from the tailgate and opened it up. It was thick in emulsified grease/thick, sticky sludge.

I stripped out the couple of gears and reconnected the bare motor. Switched on via the stalk and the motor operated fine.

Cleaned everything up with brake parts cleaner and a dremel. There are some electrical contacts which were rusty (provides a switch to ensure wiped returns to rest position) so sanded these back with the dremel.

Regressed everything and refitted it all.

It works!

Kind of!

The motor doesn't seem very strong. I've read about a dodgy earth to the wiper motor causing issues so quickly bodged a wire from the wiper motor to an earth terminal near the rear light clusters.

The motor now operates much stronger and faster.

The earth to the boot lid is/wiper motor is provided by the chassis and tailgate hinges, no wire.

Now, here's the weird thing. There are four electrical terminals on the boot surround and tailgate. These make contact when the boot is shut. Only 3 of these terminals are in use. Nothing connected to the fourth. I wired the wiper motor ground to the fourth contact in the tailgate and then ran a cable from the contact on the boot surround to the earth point near the rear lights.

Everything seems good now. I can't figure out why Ford didn't cable it like this though? Have I made a stupid mistake running the ground through this contact? The other contacts carry permanent and switched live for the wiper motor. I guess the third is related to the high level brake light.

I'll add a few pics to this thread as I think it'll prove useful to forum and Google users.
 
Last edited:
Soldato
OP
Joined
19 Jan 2003
Posts
17,542
Location
Bristol, UK
Took about an hour - hour and a half all in.

The contacts I've tried to describe are next to the wiper motor so minimal work.
 
Last edited:
Soldato
Joined
18 Oct 2002
Posts
16,660
Location
Devon
seems like a lot of work just to get a rear wiper working,

No it doesn't? Seems like exactly the right amount of work to me, since he's managed to get it working.

Using the (unused) fourth contact shouldn't cause any problems, but if there are already three contacts for the wiper motor I'd have thought one of them was ground already?
 
Soldato
OP
Joined
19 Jan 2003
Posts
17,542
Location
Bristol, UK
Using the (unused) fourth contact shouldn't cause any problems, but if there are already three contacts for the wiper motor I'd have thought one of them was ground already?
I know, it seems so obvious but nothing was connected or has been to the 4th contact. Perhaps some models utilised this contact for remote boot release (car doesn't have RF locking).

The 4th contact also acts as a mechanical switch for the boot light but it does have a lug on the back for a spade connector, so I used it.
 
Soldato
Joined
18 Oct 2002
Posts
16,660
Location
Devon
I know, it seems so obvious but nothing was connected or has been to the 4th contact. Perhaps some models utilised this contact for remote boot release (car doesn't have RF locking).

The 4th contact also acts as a mechanical switch for the boot light but it does have a lug on the back for a spade connector, so I used it.

What I meant was surely one of the three that is used is ground? If there is a permanent 12v and a switched 12v, what is the other one? Heated rear window maybe?
 
Soldato
OP
Joined
19 Jan 2003
Posts
17,542
Location
Bristol, UK
What I meant was surely one of the three that is used is ground? If there is a permanent 12v and a switched 12v, what is the other one? Heated rear window maybe?
I assumed that or the brake light (or the wiring for the boot release/ajar sensor may be in place but unused).

I wasn't getting any continuity to ground so it's not that.

I haven't refitted the trim yet as have a small water ingress issue to resolve. I resealed the rear lights a couple years ago and my hunch is it's coming in around the tailgate window so might have to get a new sill and have the glass refitted.

Cheers for posting something decent.
 
Back
Top Bottom