[Alfasteve91]

Hi all - in the middle of researching re-building my fuse/relay panel. According to the Papajam wiring layout, the headlight stalk is always powered, meaning that you can turn the headlights on with or without engine on (or even key inserted!). There are lots of other always-on "Alfetta Features" that I'm moving to be operational only when the engine is on. My question is this - is there any reason why the headlight stalk must always be powered? Thanks!

 

[alfaparticle]

The ignition switch is not rated to carry all of the current for the lights. If you really want this feature then you can run the lights through relays and rewire the car accordingly.

 

[vintagemilano]

I would have to guess that this dates back to a euro regulation about having your parking lights turned on, while parked, in certain situations.
I don’t know the diagram that intimately but does hazard flasher power come from headlight power?

 

[Alfasteve91]

Hi Carson- those were my thoughts exactly. It doesn’t look like flasher power comes from the headlights. I really want to move the headlights (using a relay) to work only when the engine is on and key engaged.

 

[samakijoe]

OK , here's the real reason.

The guy that did the initial electrical design for the whole Alfa Romeo product line (post 1951) was a bit of a party animal. He was trying to impress this blond he met at a, well let's just say that is was a Christmas office party but the were a number "extra" ladies invited to the party. So this guy is doing well with her and they decided to take the party (just the two of them) to his place where he told her that he was going to teach her all she needs to know about "Ohms Law". So they go out to his car (a prototype for the new Alfa line) and he opens the door to let her get in the car. He closes the door with his right hand and gets the key out of his pocket with his left. (a single key that he took off the key board at the office without his bosses permission.) Walking around the front of the car he bumped his hand on the car and dropped the key. Because it was a big party he had to park the car off the parking lot in the high grass. He starts feeling around for the key. Being a typical Italian he is very excitable.He could feel his blood pressure going up. So he goes to the drivers side and turns on the head lights which of course don't come on because he designed the lights to come on only when the key was in the "on" position. By this time he is really upset and saying a lot of bad words. This is getting the young lady upset. With all the screaming and yelling, her girl friends come out to see what is going on. They convinced her to go back to the party alone.

The next morning, when our hero gets back to work a few of his co-workers noticed he did not look too happy. Right then and there one of the guys in the office coined a phrase that is well known even today.
"Somebody did not get lucky last night".

Although still upset, he was able to make the necessary changes to the wiring
layout so that the lights will always go on no matter what the occasion...

Now you know the rest of the story...

 

[Gubi]

slow clap

I really want to move the headlights (using a relay) to work only when the engine is on and key engaged.

Headlight relays are a good idea, but changing them to switched power seems like an unnecessary complication. I mean, I was thinking you could install headlight relays in the normal manner and then just modify the headlight switch from constant to switched power, but then you'd be running the parking and interior lights through the ignition switch, so that wouldn't work great. So you'd need to add another relay under the dash to feed the headlight switch.

Why bother...worried about leaving the lights on and draining the battery? Packing a portable Li-ion jump starter in the trunk would be a lot less work!

 

[Alfasteve91]

What’s the emoji for “speechless”?

 

[alfaloco]

Hey Steve, you know by now I ain't bashful, so here we go...

Like most things, there are advantages and disadvantages to both approaches. By using key-switched power to the headlights and feeder circuits, you can:
1) forget about having to switch off your lights, which can become a habit, and then when you start the car again the headlight/taillight/dash lights load will immediately be on the battery while cranking the engine,
2) assure that all lighting is disabled when you turn off the key, so that when you forget something stashed in the hatchback area, which has a new lamp wired in with the lighting circuit (like the 105/115 Spiders), you have to insert the key once again to get illumination in the hatchback area to find what you forgot.
3) forget about being able to flash your headlights as a warning, or signal, unless you have the ignition ON,
4) be forced to insert your key again, switch on the ignition and leave it on, whenever you may want/need extra illumination outdoors while parked.

To me, that's all a potential PITA. Small PITA's maybe, but PITA regardless. And to what benefit? There is after all, a green indicator lamp on the speedo that tells when the park lights/headlights are switched on. So there ya go buddy!

 

[Alfasteve91]

Thanks, Mr. Alfaloco, and keep those non-shy comments coming. I was hoping you would weigh in on this, and you have.
So, as you know, I’m doing a lot of re-wiring... as much to modernize as to do a bit/lot of learning. I’m building a relay panel to go in the passenger side kick panel (covered of course) that will have the relays for the windows, wipers, and locks. Those are all switched-power relays. I want to add the headlight relays to that block and then run a big-a$$ wire/relay (fused of course) to that block. Since it’s a relay, I can get a 6-second delay so the engine cranks over before the block is powered. I’m going to keep the interior lights on the always-on block, and add a delay-off timer to those, and maybe a momentary-type dash switch to get a 30-second burst of light. I’m also running a light to the trunk off that same circuit. All courtesy lights will be LED’s (I believe that was another of your awesome ideas!).

Running the headlights off switched power makes the entire wiring scheme easier to manage. It doesn’t seem that there are any electrical reasons why I can’t do it.

Thanks everyone and stay tuned... all will be documented... smoke, sparks and all...

 

[Gubi]

Running the headlights off switched power makes the entire wiring scheme easier to manage. It doesn’t seem that there are any electrical reasons why I can’t do it.

You can run the headlight relay trigger off switched power. But as Ed noted, you do not want to run the headlights directly off of switched power: that's way too much current for the ignition switch, and would be a Bad Idea. So definitely don't pull pin 30 power to your headlight relay from a switched source.

 

[vintagemilano]

I’m looking forward to seeing your post completion, as built, wiring diagram.

 

[cda951]

Yes, and I was surprised to learn this as well when I first got my '81 GTV6--- all of the lights of the Alfetta/GTV6 are wired directly to the battery, likely to save the ignition switch contacts as surmised by @alfaparticle . Because mine came from a junkyard and had the ignition switch bypassed (I fixed this and added relays), I spent the time poring over the factory wiring diagrams and confirmed this to be true.

This is different from the German cars that I work on for a living: on all of those, from the 1950s to the present, only the parking lights work with the ignition switched off, though engaging the turn signal switch will cause only the parking lights of the respective side to light up. The headlights, brake lights, and turn signals only work with the ignition switched on.

@Alfasteve91 , you already have the relays installed, and therefore have the freedom to use either configuration, and there is no technical advantage to either in your case, unless you are worried about current draw if you accidentally leave the lights on.