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using washer switch as horn switch on Sierra stalk
harmchar - 31/3/20 at 05:38 PM

Back again with another head scratcher for the elec-trickery minded.
I'm trying to utilise the washer switch button to activate my horn, no matter how I wire it up copying the few posts I've found doing a search, the horn sounds as soon as I connect the battery again, press the washer button and it stops. So working the reverse of how I need it.
Anyone done this successfully. 92 Sierra with two post horn. Tried with and without relay. Would prefer to use a relay if possible. Would I be right in thinking I need to purchase a normally closed relay?
Thanks in advance for any info.

If I get this sorted only have my bottom harness bushes to weld in place, then ready for final build up (hopefully)

nick205 - 31/3/20 at 05:58 PM

I did this using the donor Sierra horn relay IIRC. I don't have a wiring diagram, but I don't recall it being too difficult to do. Saved having to have a separate horn button on my dashboard.

theconrodkid - 31/3/20 at 06:11 PM

try a change over relay.
at some point in time the column switches went from switched live to switched earth, try changing wires on washer pimp first.

harmchar - 31/3/20 at 06:47 PM

I think one of the posts I found on a search was yours Nick205. I've tried it a couple of different ways but switch still works opposite way from how my wiring diagrams suggest.
Another post said to use 53c as switched earth and use 54 as a switched positive but that works in reverse also.
Will look at a change over relay as Conrodkid suggests. Is that the same as a normally closed relay?
Cheers

[Edited on 31/3/20 by harmchar]

SteveWalker - 1/4/20 at 12:25 AM

A changeover relay has a common and two other contacts. Common to one contact is made when de-energised and common to the other contact when it is energised. Hence it has both a NO and an NC contact and you can use whichever suits your purpose or even both for different purposes.

Angel Acevedo - 1/4/20 at 04:33 AM

Most modern relays have 5 spades.
2 for the coil, and 3 for the working circuits.
Switch connected to coil, and you would use two of the other three...
Switching one of these three Should get desired result.
HTH

ReMan - 1/4/20 at 03:31 PM

quote:
Originally posted by SteveWalker
A changeover relay has a common and two other contacts. Common to one contact is made when de-energised and common to the other contact when it is energised. Hence it has both a NO and an NC contact and you can use whichever suits your purpose or even both for different purposes.


Just bear in mind, it would not be best practice to have a permanantly energized relay drawing power whenever the ignition is on.

You need to get the meter out and understand exactly what is goig on first. Sorry at "work" so being quick.
Yes you need a relay, ideally to manage the load of the korn , but you need to aim to power it when you press the button, not unpower it

harmchar - 1/4/20 at 06:03 PM

Got it sorted at last. Was the switch after all. Previous owner must have had it open at some point and the 3 contact plates in the switch were in the wrong place (or moved). Reset the washer button blue wire and red wire in right place and bingo. Switch works in correct polarity now. That was a bit of a head scratcher as I was convinced it was a wiring issue.
On to next job now. Fitting side repeaters to rear wing and bonding cable in place to the lip of the arch.
Cheers for replies.

nick205 - 2/4/20 at 09:55 AM

Glad you've got it sorted, the joy of building a car

harmchar - 2/4/20 at 01:35 PM

That's my thinking. It's taking ages to build this thing but the learning experience is all part of it. One guy in my work asked why I don't get an auto sparky in to fix the problems and I said cause then he would fix the problem and I still wouldn't know how.
Only advice I would give others is - never overlook the obvious. I suspected my issue to be the wiring loom that I have chopped and modified but it was the switch all along.