GTV6 Brake Lights Not Working

[AgeG]

Lads,

I am after some help please.

I just realised tonight that my brake lights dont come on. I recently changed the indicator/headlight combination on the steering wheel column so maybe i stuffed something up with the wiring. I checked the fuse box and the fuse for the stop lights is the same for indicators and they still work so no answer there.

The Switch on the brake pedal maybe???

Also i have a faulty interior light, passenger side light does not come on with door switch, only drivers side. Passenger side does work in manual mode only. Where is the door switch time delay box? Hopefully is just a loose connection or something.

Alternatively does anyone know a good auto elec who wont try and rip me off at first sight of an italian car?

Cheers lads,

Adrian Gervasoni

[derek1.08]

The most common problem many have with auto electrics (DC) is understanding that the switching is usually after the load and not before as in AC circuits. That is, the neutral is switched so that the switches dont burn out from sparking and overheating. Typically headlights etc are live all the time when car is running but only come on when the neutral is switched to complete the circuit. Relays are electric switches so that the controls can operate on very small current instead of having big switches and fat wires everywhere.
I don't know how many times I have seen people install spotlights active to neutral (without using a relay)and then wonder why the switch burns out.
I have some similar problems as you with interior lights in an 84 alfetta sedan I bought this week but as yet have not started sorting out.(gearbox needs doing first)
Wiring diagrams often scare people because they present too much information at once. The trick is to very patiently identify the components you want then follow one line at a time and the color coding should allow you to find the wire in the harness if you are trying to follow a circuit. Getting a photocopy of diagram so that you can write/draw on(in different colours if necessary) may help.
The simplest effective test instrument is a light globe with two wires (or cheap test light from auto shop)
Patience is the key. Having a rubber neck and double joints is a bonus. Good luck

[kartone]

Adrian & Derek,

I purchase a 1980 GTV six or so weeks ago:
- horn only operates when ignition key is removed (definately not an italian specification)
- when turn signal is used alternator light pulses on/off
- when turn signal is used and brake lights are on turn signal blinking frequency decreases
- when ventilation fan is used alternator light glows
- when windshield wipers are used alternator light glows.
I have the original owner's manual with electrical diagram (shows 3 relays while I have 6), the Haynes workshop manual (Alfetta 1973-1981 all models) and a good tester, all I need is time & patience.

Let me know if you think any of the electrical diagrams might assist you.

[AgeG]

Thanks guys,

In the daylight i managed to get under the dash to find the switch on the brake pedal had come loose so i fixed that relatively easily.

I will attempt to fix the interior light issue in the coming week. I have the owners manual and a workshop manual on CD so will have a browse over that before hand.

Ill let you know how i go.

Peace out.

[derek1.08]

fixing problem usually simple but finding problem maybe not always so

I am intrigued by a horn that only work when turned off (bad viagra)
looking at haynes manual electrical diagram horn button (B5) goes to multiple connector (G5) to horn relay (13) and power through fuse(#1) thru relay(13) to horn (02).
Possible incorrect connection on multiple connector (sometimes people do wrong things fitting stereo/amplifiers etc)

The other faults sound like bad neutral/earth (assuming alternater ok) but I would look to solve horn problem first in the possibility that is what is causing other faults through backfeeding as there is a connection between rear heater/fan/horn relays, wipers and other components(maybe test all relays open /close)

From what I can see, the number of relays beyond three depends on number of various options like thermo fans, rear demister, headlight wipers, fuel isolator, seat adjusters etc etc etc
good luck

[Al Campbell]

Derek is right, the circuit diagrams look scary, but it's just because they show everything at once. The individual circuits for each function are very simple. Photocopy the originals if you have them, even blowing them up to A3. Find the devices that don't work, e.g. interior lights, then trace over the circuits you are interested any with a high-lighter pen. Apart from the wires running all over the page, car electrics are very simple.

One thing to watch is that if you look closely at the circuits around the fuses you will see that two or three sets of fuses are joined together on the live/hot side. And I've noticed that they loop circuits through several relays.

Caution though, the circuits are not always 100% accurate. I have the original Owners Handbook for my 1984 GTV6 and I've found 2 errors so far: The Radiator fan is shown as being switched directly by the temp sensor on the radiator, but it is actually switched through a relay (as it should be) and it shows only one warning light for Hand-brake on and low brake fluid, when in fact there are two separate lights, which is probably a change for the ADR.

Kartone, to re-enforce what Derek said, check all the earths. Also these ALFAs have low power Alternators, 55A or 65A instead of the more usual 90A or higher. At idle they produce even less power as output depends on rpm. If you haven't done so yet, undo all your earths, clean them back to bare metal with wet & dry or something similar and do them up good and tight. Also there is a common point where all the positives come together on the firewall (battery, alternator &c...). Disconnect the battery and clean these as well. Disconnect the battery as you are playing with unfused 12v from the battery there and you'll melt something if you let a live cable touch an earth such as the chassis.

One earth that I forgot until recently is from the battery to the chassis in the battery box in the boot. My car has had a new negative cable installed fairly recently (modern, shiny connectors) but the joint to the body was corroded already and I was loosing 1.5V through that joint and that's before the power gets anywhere out of the battery. The bolt used goes through the sheet metal to a nut welded to the outside, so the end of the bolt is exposed to moisture under the car. I brought a small tube of dielectric grease and smothered all the clean surfaces before reassembling.

[Alan Hopla]

Derek,

I know this is getting a little off topic but can you clarify the statements below please.

The most common problem many have with auto electrics (DC) is understanding that the switching is usually after the load and not before as in AC circuits.
That is, the neutral is switched so that the switches dont burn out from sparking and overheating.
Typically headlights etc are live all the time when car is running but only come on when the neutral is switched to complete the circuit.

I am unclear on what you mean by 'neutral'.
In a negative earth car like these Alfas I am more used to using terms such as Earth, Ground or Negative for the path through the body shell to the battery, and +12V, Live, or Positive for the path from the battery through the loom. Which of these paths do you refer to with the term Neutral?

Either or both of these paths can be switched to control the circuit, however if I look at a typical Alfa wiring diagram from an Alfetta I find that most components are locally Earthed to the body, and that the other terminal is the switched path where the switch is live and is activated to have +12V applied to the component.
This includes the lights, thermo fan, horn units, starter motor, heater fan.
Some components do switch the Earth line however, one such item is the relay that activates the horn, and another the relay that activates the thermo fan.
Here the relay is always live, and the control circuit for the relay is switched in the Earth path, for the horn this is through the horn button which completes the circuit to Earth at the base of the steering column, and for the thermo fan this is through the thermo switch at the base of the radiator.

With regard to the statement about headlights typically being live, in my admittedly limited experience I have not found this to be the case.
Though I think that early Datsuns like the 1600 did have there lights configured this way.

Regards,
Alan.

[derek1.08]

Good points Alan. gold star
I was wrong by saying "usually switching is after the load" and "typically headlights are live..." I am full of it sometimes. I would have been more correct if I had used the word "sometimes" in some cars, instead of usually and typically. SORRY!

The term 'neutral' I have referred to is the conductive wire after the current drawing load and yes it is fairly commonly referred to as negative or ground in DC circuits. To be an argumentative sod though I would say positive is to negative as active is to neutral and in the case where the negative terminal of the battery is significantly connected the body of a vehicle, yes the term negative earth (or ground) is used, This is to say the entire body of the vehicle is an extension of the negative pole/terminal. (The heavy conductor between the negative terminal of the battery and the earth in this case is the negative lead). The neutrals then connect to the negative pole/terminal via the body/earth/ground. But by all means call them whatever you like. What you call a wiring loom I call a wiring harness but I know what you mean and loom is fine by me.
You are absolutely correct to point out that either the active or the neutral (positive or negative)can be switched. To clarify and correct my previous meaning is, that switching neutrals is difficult for some people to understand. As for example in such cases, using a voltmeter to find a fault can get pretty confusing sometimes. Not so bad if your eyes can move independantly like one of those lizards. A test light is much easier and quick by comparrison.

I might suggest that theoretically in ideal circumstances load bearing DC circuits are better switched after the load for less wear and tear on the switch contacts from arcing and sparking. No this is not always the reality as convenience, practicality,simplicity and cost effectiveness rules and my comments were not alfetta specific (sorry everyone for such a hienus crime ). You mentioned Datsun, I'll add Mitsubishi whatever, I have been confused more than once. And the next time I get electrocuted I hope it is after the load.
I knew and old bloke once who had worked on 32V DC  country town power supply way back and I remember him telling me that with Direct Current electrocution wasn;t a problem for your heart, couldn't hardly feel it but because of the amperages involved it was possible for joints in your body to just explode(knuckles, wrist elbow etc) because the calcium in your bones became the main conduit and arcing occured between bones. A friend now who works on the Qld State Grid says so what, with high tension DC electrocution isn't a problem, if you put your hand anywhere near the wrong place it will blow your whole f#* arm off and it's the fall that will kill ya.

To be honest I believe Alfa Romeo, if instead of using a negative earth through the body they had used a neutral block (junction) with a negative lead to the battery we wouldn't be dealing with anywhere near the amount of rust in the vehicle as we do.  Cars that do this still rust but not as quickly. The down side of having a neutral/negative block is there are a lot more wires in the loom/ harness as every circuit would have a wire returning to the engine bay instead of simply grounding to the body. From memory BMW (77, 320i)did this - bloody wires everywhere. Ducati motor cycles also (77 860GTS) and I think a number of older British cars (67 Rover 3.0L) and I think 67 VW bug was positive earth. If my memory serves me correctly.
I don't know how to expain electrolysis simply but when you need to clean the terminals of the battery, which one actually needs cleaning due to corrosion? Which one is fatter than the other? (because it rots). Nowdays you can install some electronic gizmo that is supposed to stop corrosion but I don't know how they work.I don't know if they work. I dont care. I use auto/body filler/putty/plaki/bog  it does',t rust(fall out maybe if i didnt use fish oil first) I enjoy driving my little alfetta more than I enjoy working on it, especially elecrical faults. Just to add a little more confusion I understand that theoretically we may refer to positive and negative but the electrons flow from negative to positive
I know this is getting a little off the topic but if you ask me why if switches are theoretically better on the negative side wouldn't they corrode and fall to bits I am going to get my lunch box, put it in my bag and go home so there. 
Thank you for the opportunity to get it right (I hope)
kind regards
Derek

[Al Campbell]

Derek,

I decided not to be pedantic and question the use of "Active" & "Neutral" in DC circuits , stuck out like Dog's B***s to me . I'll have to have a think about your idea about the placement of switches relative to the load and "common/return" to limit arcing. Wouldn't the current across the contacts be the same? Unless there is an alternative path for back EMF &c... Not having a go, it's an interesting idea.

Is it the electrons flowing from negative to positive, or the holes flowing from positive to negative  (sorry)?

And I've worked for a company for 20 years that uses a positive common/return for 48V DC!

And I had the cam cover to body earth strap off my GTV6 last night, so put some di-electric grease on for good luck.

AL

[alfagtv58]

Aw you guys, trying to figure out logic in Italian electrics....will the fun never stop 

Having said that, the only thing I know about electrics is if you let the compressed smoke out, it wont work again.

[derek1.08]

Hey Al
Barleeze mate before we all fall into a black hole. (neutral: a state between two beligerant forces)
Phil is spot on about compressed smoke i luv it (protons,elecrons and neutrons all at once)

Benjamin Franklin flew a kite during a storm with a key tied to it.
rhetorical question; was that a smart thing to do?

ends Derek

[Jekyll and Hyde]

Aw you guys, trying to figure out logic in Italian electrics....will the fun never stop 

Having said that, the only thing I know about electrics is if you let the compressed smoke out, it wont work again.

A couple of years ago someone had an item on Ebay titled "Lucas wiring replacement smoke".  It was a small glass bottle, and the description was something to the effect of "Just put electrical tape over the point where your wiring is leaking, then use a syringe to inject the replacement smoke back into your loom.  Will repair all electrical faults on british cars!"  Think it got up to about $50    Probably need Spica or Veglia smoke to repair an Alfa though.....

Adrian & Derek,

I purchase a 1980 GTV six or so weeks ago:
- horn only operates when ignition key is removed (definately not an italian specification)

This one is simple.  Where the steering column meets the rack, there is a universal joint, which has one very long side to it where it joins the steering shaft.  The steering shaft feeds inside this universal joint, and is actually just bonded to the uni joint by rubber.  For this reason, there is a small piece of braided wire with ring terminals either end used to bridge between the end of the uni joint and the steering shaft, held on by little flathead machine screws.  It will be broken on your car, make a new little wire up (use the remains of the old one to get the right length) and fit it, horn will work perfectly.  Make sure not to make the wire too long, or use big terminals, as they will catch on the firewall and rip the wire straight off again.

[Alan Hopla]

Derek,

Thanks for the reply.
As you say driving these things is much more fun than fixing them, though I think I do more of the later.
Mind you it is a Sunday car, and used mostly on the track so has a pretty hard life.

I would say though that it is much easier to fix a wire that has had the smoke escape, than it is to fix an electronics box that has done the same. 

Now if a Smiley appears on the line above thats another new forum skill I have acquired, now I can do quotes and graphics!
Next thing will be to get a decent picture for my signature.

Alan

[kartone]

Jekyll & Hyde

will certainly check & repair the connection indicated

many thanks