Rear wash/wipe circuit diagram

[MarinaCoupe]

I'm looking to fit a rear wash / wipe to a car and am looking for a wiring circuit including a relay to time the wiper after using the washer. I have got a single speed wiper ready to go and a switch, what I need is the relay circuit and a suggestion for a relay as some are 4 pin and some 5 pin.

Bottom line is the simpler the better.

[TerryG]

Is it a normal single speed front wiper motor you are wiring up? rear wiper motors are different as they only wipe every few seconds.
A normal 4 pin relay will be fine as long as it is rated up to the required current of the motor you have.
Ignoring the physical fitting and the throw, connecting one electrically is pretty easy.

Using a reasonable capacity wire from battery positive to a location close to the wiper motor itself and connecting it to one of the switched terminals of the relay and to the permanent live connection on the wiper motor. Running the other switched connector on the relay to the switched live on the wiper motor. Run a lower capacity wire from an ignition switched live to your switch then from the other side of your switch to the positive coil terminal on the relay. ground the wiper motor and the negative side of the coil on the relay.

If you need I can draw a basic diagram for you.
You will need to find out how much current your motor draws so you can get an appropriate relay and gauge of wire.

[Luxobarge]

Using a reasonable capacity wire from battery positive to a location close to the wiper motor itself .

Oooh, I really wouldn't do that! - take the power feed from a fused supply, or at least put a fuse in the circuit as close to the battery as possible. Remember, fuses should be there more to protect wiring than the devices that they feed. Personally, I'd probably look to take the feed from the same place that the front wiper motor is fed from, if at all possible. You can use an in-line fuse, but I've had a number of problems with them not making very good contact in the fuse holder so a proper fixed fuse-box arrangement is probably better. All depends on what car it is I suppose!

Just thought I'd better mention it - I've seen a number of total losses caused by un-fused electrical installations, in one case on a nearly-new Honda Accord which very nearly cost the owner his life. (And nearly cost me my car, which was parked next to it!)

Cheers!

[MarinaCoupe]

It's actually to build a wash/wipe for my Marina. On a modern car a wash/wipe only works on the slow speed, so I'm hoping it's like a single speed system.

I already have an intermittent wipe relay fitted (Lucas 6DA), so I want to complete the job.