Fiat Bravo electrical problems

Apologies for the length of this message and the X-post.

My girlfriend's Fiat Bravo (1996 1.8GT) has been developing an electrical problem over the last few days. It's a new car for us so I'm not totally aware of its history.

It started with the indicators; when signaling right everything was ok, however when signaling left it's fine until you brake, when you brake the indicator stops (or goes very slowly) and there's no sound from the flasher unit. When you release the brake the signal resumes normal service. Looking at the rear cluster when this happens, normally the orange indicator flashes, when the brake is depressed the rear light flashes instead of the indicator but it is dim and irregular.

It has been doing this for a while with no other problems but this morning when I tried to start the car there was nothing, it was completely dead. The battery had so little charge that when I turned the key, the clock on the radio reset! I boosted it from our other car and it then started. I took it for a blast up and down the A14 for a couple of junctions to try and charge the battery a bit. When I got back home I tried turning it off and then back on again but it wouldn't start. Another boost got it going again.

Upon some investigation it appears that a third party alarm has been fitted at some point (quite badly I might add). It's made by a company named Spal. Aside from that I've got no more information about it.

My current diagnosis is that the alarm installation is faulty causing a short or open circuit between the indicators, brake lights and rear lights which is the issue with the confused lighting when indicating and braking. This short is also discharging the battery rapidly and a cycle of charges and discharges to almost no charge has damaged the battery which is why it now cannot hold charge. Do you think I am on the right lines here?

My next course of action is going to be to call the AA (I have home start) so they can come out and do a battery test so I know if I need to buy a new one. This won't fix the original wiring problem though. How might I go about tracking that down? I guess a multimeter will be my next buy?

Any tips on what I can do to try and sort this out?

Please help, I'm starting to get nagged by SWMBO!

Thanks all.

Cheers,

Robin

Reply to
Robin Cull
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This sounds like a classic earthing problem. There will be a dodgy earth from the rear light cluster (probably from the bulb holder); pull all the bulbs out and clean all the earth points, as well as the connector to the light cluster itself.

It could be either the battery has failed (they can go suddenly), the alternator is duff, or something else is drainig the battery. If a good blast didn't help, then i'd suspect one of the first 2. Get the engine running, and check the battery voltage with a multimeter; If you get less than 13-odd volts then the alternator is duff. Elsewise, it's the battery.

The alternator could be causing the battery drain if the diode pack has failed...

Reply to
Phil Howard

Running the engine may not put enough charge in the battery. A totally drained/dead battery is normaly charged at about the 10 hour rate. A boost charge may get the vehicle started but the battery needs to be fully charged before you can accurately determine its condition. Knowing the age of the battery also helps. Complete discharge is not good but rarely terminal if the battery is promptly recharged and in otherwise good condition. Many with boats leave the battery to look after itself out of season, they self discharge until flat, most when recharged survive.

Best thing you can do is get a low wattage 12V bulb with a pair of wires attached and put it in series with the battery post and its clamp. I usually use a jubilee garden hose clip on the battery post, for the round post types, to make the connection to the post. The clamp has its own bolt for the other connection.

Now how bright the bulb glows is a measure of the drain. Should be out with the ignition, lights, radio etc off. If not get someone to watch the bulb while you pull, then push back, each fuse in turn. If one turns off or dims the bulb that is one source of the drain located.

If the bulb stays on and no fuse affects it, the drain is on the raw unswitched battery feed. Could be alternator, or one of several other possibilities.

Fiats are well known for earthing problems but a bad earth, whilst it may make various lights not work properly, is unlikely to create a drain on the battery. Being a high resistance the opposite.

At a guess you have two separate problems, the battery discharge and the interaction between the brake/indicator lights.

A test of charging is start the car, get someone to watch the headlights on a dark night, or point the car to light up a wall, rev the engine, the lights should get brighter if so you are getting some charge from the alternator into the battery. The battery light should also go out at revs above tickover.

Diagnosing alternator problems can be a DIY if you are familiar with electrics, but is usually left to an auto electrician. The main alternator feed is live all the time and very bad things can happen if it touches the chassis. DIY arc welding.

Reply to
ato_zee

Sorry you've lost me here with terminology. What do you mean by "clamp"? I assume post is one of the terminals on the battery itself.

Maybe I should have told SWMBO that /before/ she bought it! :)

I think the alternator is working ok, for example, when on tickover there is a change in revs as the cooling fan cuts in or you switch the lights on. I assume this means that current drawn from the alternator is increasing the load on the engine. If the alternator was knackered this wouldn't happen, right?

Sounds nasty. I've promised to take it to a pro if I get out of my depth!

Cheers,

Robin

Reply to
Robin Cull

Earthing problem. Ok, I'll check the rear light cluster and make sure it's all in reasonable condition.

On a multimeter:

Engine not running: 12.7V Turning ignition:

One to look out for.

Cheers,

Robin

Reply to
Robin Cull

That to me sounds like a knackered battery - when it is called upon to deliver a large amount of current, such as starting the engine, it dies. Stick another battery in and see what happens!

Hellraiser.........>

Reply to
Hellraiser

Seconded. Also you can take it to a motor factor shop as most offer free battery testing.

Reply to
Conor

The clamp is the bit that goes on the post. A low wattage 12V bulb between the post, and the clamp that goes on it, is a quick and cheap way of seeing if there is any drain on the battery with everything switched off.

The test of charging is whether the lights brighten when the engine is started or reved. They should also dim a little as the revs are dropped to tickover.

Reply to
Ato_zee

Got it! I thought clamp was some terribly technical term, not the obvious. I feel a bit dumb now.

It's completely obvious now, a bulb in series between the battery terminal and the bit that normally clamps directly to the terminal will light if anything is drawing through the battery. I'll put something together tomorrow.

After listening to the revs as the cooling fan cuts in and sticking a multimeter over the battery while the engine is running, I'm fairly happy that the alternator is charging the battery.

I've got it trickling overnight to see if that'll get the battery to a state where I can start the car tomorrow. From a couple of other posts and a friend's opinion I'm pretty convinced that it is new battery time.

Thanks for your help.

Cheers,

Robin

Reply to
Robin Cull

Thirded! It was the battery. Took it for a test and it was pronounced dead at the scene. New battery in, car's starting fine.

Thanks for your help.

Cheers,

Robin

Reply to
Robin Cull

Glad to be of help ;)

Hellraiser.......>

Reply to
Hellraiser

Hmm. I owned a P-reg Bravo 1.8HLX (there's no 1.8GT as far as I know) that had a bad earth in the left light cluster. Is this my car? :P

Metallic blue, a crease in the driver's seat near the door?

A
Reply to
antgel

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