I have been searching for the cure to an electrical problem which appeared at the weekend in my 97 Fiat Bravo 1.4 12v and hope someone can please help me.
Dip and beam headlights, wipers and inside heater fan have all stopped working.
I have checked fuses and all are ok although one may have been blown.
When I supply power to the fuses the lights etc work.
I have also checked the plugs on the back of the ignition switch and all seems to be in place. Doesn't seem to be anything out of place under the bonnet. Large fuses are fine Thanks Bob
With a test lamp (small 12V bulb and a couple of pieces of wire, or buy a test screwdriver from any accessory shop) check whether supply is getting to any of the headlight bulbholder contacts. If it's getting to the bulbs you may have a push on blade grounding problem. The strips you push the grounding blades on to are often exposed to road spray mist, if they oxidise wierd electrical problems can arise.
Dirty headlight contacts would not explain the heater and wiper stoping at the same time nor the lack of feed to the their fuses.
The problem has to be somewhere between the battery and the fuses. Perhaps a plug.
As I am stuck without the car I added a feed to the dip beam fuse. To my surprise everything started to work on the way home this evening so it has to be a bad connection or relay.
Check whether there is any voltage at the bulb holder. If there is it is prtobably a grounding problem. If there isn't then you have to get at the ignition switch, then follow through to the associated lighting switch, checking as you go that turning the ign switch produces the expected voltages at the output of the ign switch contact block. I've known the molded contact blocks to cook and fail. From the contact block there is a feed to the headlights and other switched services (including the heater). A basic failing of Fiat electrics is that the headlight load, in most cases, goes through the ign. switch, which can cause problems. The switched output being headlights, heater fan, wipers, radio, and a few other items, which is a fair sized load. You check at the headlights first because it is an easy test, getting at the ignotion switch a bit more difficult, if you need to replace the ignition switch the job is a pain in the butt. Sometimes you can just replace the contact block. If you replace the switch then think about ordinary hex head bolts rather than the snap head security bolts that come with the new switch. Car theives don't usually bother with dismantling, so break head bolts are a bit of overkill. Changing the switch can lead to one key for the ign, one for the doors, and a third for the tank.
I suffered exactly the same problem this afternoon on my '98 1.4 Bravo. I was just about to post when I saw your post.
I was going to try a feed to the fuse but it is too cold outside now! Nice to know that that will probably work. Do the switches work with a feed? In other words which side of the fuse box do the switches live on? Do you suppose it could be a faulty fuse board? With no wiring diagram, I'm just guessing but that chunky red cable looks like the fuse board feed. If I were a contortionist, I could check continuity from there to the fuse spades.
If I do do a feed to the fuse, do you know which side I should use so I don't bypass the fuse?
Is there a relay in there someplace? Is that correct?
Jumping power to the fuse contact shows the outbound fuse board through bulb and ground works. Or is it just demonstrating that a headlamp relay works?
You have determined that you have power out of the ignition switch. Have you been able to determine if you have power out of the headlamp switch? I didn't get that far on mine, as my fingers numbed to sausages in the cold. I'll have another go later.
If there is power out of the headlamp switch, is there power into the fuse board? Does anyone know which plastic contact in the fuse board comes from the headlamp switch? If we have juice all the way there, it is a faulty fuse board I suppose.
The heater fan and the headlights obviously can't share a ground, so it must be feed.
I can't tell if it is easier to get at the heater switch or headamp switch to see if there is voltage that far. Anyone know? I suppose the heater switch is easier to deal with as no guessing about which wires are for what.
With a bit of ingenuity it is possible to add a pair of wires to a blown blade fuse. Makes testing easier, you can test with a 5W 12V bulb to chassis from each side, also put a bulb across the contacts in place of the blown link, if there is a load (and supply to the fuse) the bulb lights. You can't solder the connection, the blades plastic melts. I had some fine bolts. Meters aren't ideal for fault finding, apart from having to look at them, they give a reading through high resistance joints. A bulb is a more reliable indicator, and if you use twin flex you can put it where you can see it. Even on your back, with the seats out, ferriting in the under dash area, or in the boot diagnosing why the rear wiper wipes when you brake. Some Fiat joints are rivited and the joints can go high resistance. Met this in rear light clusters, there is a sort of PCB with the bulb holders rivited on, moisture and oxidation can cause problems, fortunately the PCB material seems reasonably heat resistant and you can solder a bridge to bypass the duff joint. Some early Fiat inline connectors didn't have latches, you needed a Tywrap to keep them mated.
!! On my back in -5C with a mini maglight in my mouth, and my cheap-o voltmeter that had the probes fall off so I just have two frayed ends to push against, I can see the value of using a bulb and twin flex!
I actually just figured it out while doing the above contortionist exercise. See my other response if you are interested.
I figured it out. While I was poking with my voltmeter at the wires coming out of the plastic connector that comes out of the headlamp switch, the heater fan would intermittently come on. I thought it was some relay I could hear going getting shorted by my voltmeter. But it turns out it was the top-most wire at the connector. An orange one (maybe red, hard to tell in the light of my LED flashlight) that has a tight kink in it. Pushing it into the connector made everything work, pulling it a bit made everything stop. The wire has a few sharp kinks which I guess help it work itself out of place after a while. I didn't fix it yet, I'll wait til tommorrow and daylight for that, but at least I know what to do now.
I can only imagine what sort of shaft the shops around here would give me to figure that out and fix it. I'm almost temped to give the wire a little tug and go drop it off for an estimate. I'd have ended up with an new ECU, fuse board, ignition switch, and who knows what else.
Just experienced exactly the same problems on my Bravo.
Did you ever cure the problem? Is there a common relay between the 3 circuits?
I?d appreciate some advice if you have any.
many thanks Andy
"Bobp" wrote: > I have been searching for the cure to an electrical problem > which > appeared at the weekend in my 97 Fiat Bravo 1.4 12v and hope > someone > can please help me. > > > > Dip and beam headlights, wipers and inside heater fan have all > stopped > working. > > I have checked fuses and all are ok although one may have been > blown. > > When I supply power to the fuses the lights etc work. > > I have also checked the plugs on the back of the ignition > switch and > all seems to be in place. Doesn't seem to be anything out of > place > under the bonnet. Large fuses are fine > Thanks Bob
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