I'm trying to locate the black/brown wire marked "T1a" on the '74 wiring diagram, that is supposed be "near fuel tank", and which I think can be used to power an electric windscreen washer pump (it comes from the stalk switch on the steering column).

My problem is that I can't see where this wire is on my car. There is some overspray on the wire bundle that emerges into the front trunk from under the dash, which makes seeing what is there difficult.

Any help/advice would be appreciated!

That wire is for an intermittant wiper relay and IIRC come out with the wiper motor harness.

It's brown with a black stripe. Originates at your steering column and is in the main bundle going into the front trunk and terminates right around the drivers side fresh air divider box thing.
It may be hidden inside the loom. It was on my car.

http://www.914world.com/bbs2/index.php?showtopic=13261

Andy

Brilliant! Your photos are a great help. (For some reason I missed your post during my searches.)

Many thanks.

OK I have found the wire: it emerged at the place you indicated, and was folded back and taped, hidden, to the wiring bundle.

After extracting it, I checked for +12V when pulling the column stalk towards me: nothing. My car is a '74, but it doesn't have the intermittent wipe option - is that relevant?

I'm a little confused now, as my owner's manual says that the windscreen washers are activated by pulling on this lever, as I am doing. Yet the system in the '74 used the spare tire pressure to eject the water, so how is the column stalk supposed to turn that on and off, and what has it got to do with the brown/black wire?

Sorry, I'm new to 914 wiring

It's been a few months since I went thru mine but if I remember correctly that wire completes the ground and closes the circuit. No
power at that wire. But look in the classic section. I think Andy has an article that addresses how to add an elec ww pump. I'd put more effort into this but I'm using my phone and it's a pain.

Read up on it here, I hooked mine up to work pulling back on the lever as Andy describes, works great!

http://www.914world.com/bbs2/index.php?showtopic=13261

Thanks - yes, I'm following Andy's instructions, however, I'm not getting B+ on the wire when pulling the stalk switch.

I wonder whether this method will only work for cars equipped with the intermittent wipe option? Does yours have that option?

If i'm not mistaken, the stalk at the steering column grounds out the wire, not feed it with 12V ...

It usually plugs into the intermittent relay harness, i'm guessing it get's voltage from there.

In order to use it for the pump, use it as a ground for your pump or use it to ground out a relay that supplies 12V to your pump ...

Andy

and yes mine does have that option.

I'm not getting any action on that wire at all. Measuring resistance to ground or to B+, it's infinite, whether the column switch is activated or not.

I suspect it's not connected in the column, perhaps because I don't have the intermittent wipe option on my car (why would they cable the switch if the option wasn't selected?).

So I will take a look at the wiring on the switch itself, which looks like it may be quite a game getting to

Did you brake off the plastic tab to allow the lever to go down one more position to activate the intermittent option?
Andy

No, I didn't, but the reason it doesn't work is that my wiper switch does not have a pin out for the black/brown wire. I suspect there is a different wiper switch if you have the intermittent wipe option, which would have this pin connected.

Here's a photo. Yellow arrow shows the brown/black wire that ends up in the front trunk area, green arrow shows the pin socket, for which there is no matching pin on the switch base.

Thanks ... it looks like I may need a different switch.

Interesting ...

My '74 column had the switch and pin and wiring even thought the car that it came out of did not have the intermittent harness or relay.
Andy