Rear wiper motor relay - RRC

My rear wiper isn't working. I bought a replacement motor from eBay
but its slightly different. how annoying. However I now think that it
may be the relay that is at fault.

Armed with my multimeter, it appears there is a constant 12v coming
down the wire to the motor when the ignition is on. Surely voltage
should only appear when the rear wiper button is pressed.

Does this mean that my relay is faulty? apart from swapping it, is
there any other way of testing a relay? Relay part is PRC7404. Dont
want to have to pay £30 odd if its not the fault.

Thanks,

Paul
1992 RRC Vogue SE

Pacman wrote:

> My rear wiper isn't working. I bought a replacement motor from eBay
> but its slightly different. how annoying. However I now think that it
> may be the relay that is at fault.
>
> Armed with my multimeter, it appears there is a constant 12v coming
> down the wire to the motor when the ignition is on. Surely voltage
> should only appear when the rear wiper button is pressed.

It needs a permanent feed (when the ignition is on) to allow the motor
to park. There's a set of contacts in the motor.

> Does this mean that my relay is faulty? apart from swapping it, is
> there any other way of testing a relay? Relay part is PRC7404. Dont
> want to have to pay £30 odd if its not the fault.
>
> Thanks,
>
> Paul
> 1992 RRC Vogue SE

I hope that the old motor wasn't just suffering from seizure of the
output shaft - that's usually fixable.

Pacman wrote:

> My rear wiper isn't working. I bought a replacement motor from eBay
> but its slightly different. how annoying. However I now think that it
> may be the relay that is at fault.
>
> Armed with my multimeter, it appears there is a constant 12v coming
> down the wire to the motor when the ignition is on. Surely voltage
> should only appear when the rear wiper button is pressed.

No. It's auto park, yes? That 12v is present so that after you switch
your wiper off the motor can still move to park itself. Check with the
wiper that you've bought whether the motor itself is the same or
compatible with your drive gear from the old one.

Regards

William MacLeod

On 2006-01-04, Pacman <[email protected]> wrote:
> My rear wiper isn't working. I bought a replacement motor from eBay
> but its slightly different. how annoying. However I now think that it
> may be the relay that is at fault.

> 1992 RRC Vogue SE

On my 89 RRC, there is also a reed switch attached to the motor, in
a brown bakelite canister about an inch long and 1/4 inch diameter.

Mine stopped working ages ago and I must admit I haven't bothered
to fix it - there's normally so much crap inside the car that I
end up using the external mirrors anyway.

--
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Pete Young [email protected] Remove dot. to reply
"Just another crouton, floating on the bouillabaisse of life"