Ignition relay query

[GTVeloce]

I am looking to install an ignition relay to assist my struggling electrical system when I have many things operating at once (especially the AC), however, I have searched the forum (and the net) for help and everything that comes up for ignition relay seems to be referring to a starter relay. Whilst a starter relay sounds like a sensible improvement (and one I will do) I am particularly interested in an ignition relay but not sure which wire on the ignition switch I am tapping into i.e. Is it the brown wire from the ignition switch?

Thanks in advance.
Julian

[kartone]

GTVeloce, I installed an ignition switch relay sometime ago and it made quite a difference. Let me see what I did and will get back to you tonight.

[colcol]

I had the same problem with my 33 years ago, the ignition switch is just not heavy enough to run every thing, if you use just one relay to run everything it will need to be  about 80 amps or so.
I have a seperate relay for air conditioning, lights, thermo fans, horn, heated rear window, etc, you use the ignition switch to turn on the relays, and then the components have power from the relay, not from the ignition switch.
The 33, 75, 90 and GTV 6 [Alfetta] all have the same ignition switch.
When i used to turn on the airconditioner, you could smell the switch burning.
If you use one big relay, when it fails, you have no electrics, if you use several relays, then if one relay fails, its not the end of the world.
I have said it before, so i will repeat myself, that i wired up one headlight through a relay, and left the other side working off the ignition switch, and one was white, the other side was yellow...you can work out which is which!, Colin.

[kartone]

GTVeloce, as Colin indicated it is best to use individual relays to power-up the big amps circuits.
In my case I mounted a 40A relay on the metal frame on the lower part of the dashboard up above the fuse box; connected terminal 86 on the relay to ground via the same screw fixing the relay on the metal frame.
Connected the brown wire from the ignition switch (tapped on connector half-way down steering column) to terminal 85 on relay.
On the power side I connected the brown wire from the fuse box (fuses 6, 7,& to terminal 87 and the red wire from +12V (tapped on the connector half-way down the steering column) to the last free terminal on the relay.   

[Mick A]

That last one needs to go to pin 30. +12v

There will be two outputs marked 87 on many switching relays.

[GR-124]

Thanks for passing on some great info here guys. Ive always been Ok at the mechanical stuff, only now, in my forties am I starting to get my head around the electrics.
It guys like you that edumacate my grey matter.

[GTVeloce]

Yes, some very helpful advice here. Thanks to those who chimed in.

I spent a couple of hours today and have successfully wired up an ignition relay and a starter relay. I mounted them both in the engine bay for a few reasons but mostly I am sick of working under the dash area! Still had to run two cables through to there but they were pretty easy. +12V is coming from the junction box next to the relays which is coming straight off the starter motor. Used some decent 8G cable for power and earth and it has worked really well. The acid test was the indicator speed with the AC, fan etc on. I kept having to turn the AC off so that my indicators were effective! Now, they barely change with as many current draws I could try. Wipers are faster, electric windows are faster etc.

The starter relay made less of an impact (starts a little quicker) but I am happy in the knowledge I won't have to change my ignition switch again because of the dreaded clickety-click.

When I get a chance I will draw up the wiring I used for both so others can utilise.

[colcol]

The starter relay was the first relay i wired up in 1987, on the 33, you would try to kick the starter motor over, and all it would do is go click, so instead of a undersize wire going from the battery to the fusebox to the starter switch to the starter motor, it just went from the big wire on the starter motor 150mm back to the relay then 150 mm back to the starter solenoid and bingo works every time.
Had an embarrassing incident, where i was somewhere i shouldn't be, [no not that!], up the road looking for a job with the opposition, sneaking around, when i came out my car wouldn't start, vowed at that moment to fit a starter relay, still works 27 years later, what a pity Alfa Romeo didn't use thicker wires, Colin.

[Thevak]

I recently changed over starter motor on my 33. Is it possible I could have avoided this by the suggested relay modifications.

Also a good time to announce I have finished the Alfa and iT is ready to be returned to the road and track. Looking forward to it!

Good time to ask what is redline on the 1.7IE 8V as it rapidly climbs to 4000 to 5000 and seems it could higher than the indicated 5500?

[colcol]

Changing the starter motor in the 33 is very easy, on top of the engine, just looking at you, if the starter motor was going click without kicking over, then it might need a starter relay, fit one and see if it works.
You don't have to rev the t1ts off on a 1.7, as it has good usable torque, the 33 TI on the other hand, the 1500 has a big bore and short stroke and no torque, Colin.

[Beatle]

If you only wish to use a single relay, get one of the metal case jobbies sold as a "continuous duty solenoid".  It'll handle the current.  Oh, and a spare....