306 Very Random Electronics....

[madspikes 41 1 Cars]

 

 

Ok, the 306 has been a little random as of late, more so than normal. Like the wipers came on all by them selves the other day, and the heater fan seems to have direct electrical connection to the engine temp gauge, but these are by-the-by.

 

This morning I got 300 yards from home and all of a sudden the wipers came on and all (and I mean all) the dash lights came on and started flashing, including fog light warning lights and indicators. I stopped turned the engine off, turned it back on again and the flashing stayed. After a while of pulling out random relays, the wipers and flashing stopped. It however restarted again if I used the wipers, or on turned the head lights on, using the indicators was fine! Oh and to cap it off, the rear wiper which has been broken for ages, came on with the rest of the wipers!

 

The flashing of didn’t seem to change the functioning of the car, eg the headlights weren’t actually flashing. All very odd. Oh, and it’s a early 306 with a CAN bus!

 

The central locking has also behaving very oddly. Unlocks fine with the remote, but most of the time will not lock with the remote and a key in the drivers door only locks the drivers door!

 

I'm thinking there is something on the CAN bus that is screwed - and currently I think it maybe the central locking!

 

Bloody thing!

 

Clive

 

 

 

 

 

[welshpug 1,657]

306 does not have canbus nor any kind of multiplexing, so it'll be some sort of wiring fault.

 

I would check the main front end loom where it travels under the front crossmember, and also the plug from front end loom to the interior loom which is under the wiper motor.

 

central locking faults are typically from breaks in the door to body wiring looms, sometimes corrosion to the pins in the plugs.

[madspikes 41 1 Cars]

I would have sworn that the phase 3 306 was can-bus / multiplexed wiring, however I have owned and taken apart a few pugs they do all kind of blend together in my mind! Quite happy to believe it’s not – feel happier debugging a standard loom.

 

The fault was just so random, all the electronics were just going mad! Engine was still running and driving fine!

 

I’m not sure if the randomness of the central locking is a cause, part of or just another fault has occurred!

 

Clive

[Anthony 1,003]

306 isn't multiplexed / can-bus - that was reserved for the next generation cars (eg 307) as well as Phase 2 Xsara's.

 

What you might be getting confused by is that Phase 3 306's had a primative form of BMI/BSI that controlled the central locking, immobiliser etc.

 

My best guess for the sorts of issues that you're seeing is either an earth related issue, damp in the fusebox, or I know that the large multiplug (as Mei mentioned above) that joins the engine bay loom to the interior loom can suffer moisture ingress or poor connections, and this can cause some wierd and wonderful issues.

[Rich_p 23]

A friends Mrs' old 306 was doing similar. It turns out the main earth lead was almost broken through.

 

He has a similar issue that's reared its head this week. Turn the car off, take the keys out and the battery light stays on and the heater blower keeps running!

 

Taking the fuse out stops the fan. Put it back in the fan doesn't restart but the light comes back on!

[pug_ham 244 3 Cars]

A friends Mrs' old 306 was doing similar. It turns out the main earth lead was almost broken through.

I had similar isues with the dash gauges / lights on my hdi giving spurious indications & that was also the chassis to gearbox earth lead which had sheared off on the ring terminal end to the gearbox earth point.

 

Unfortunately the M7 bolt holding it to the chassis leg sheared as I wound it out so I still have a temporary fix with the wire joined & a separate wire running to the suspension turret.

 

g

[madspikes 41 1 Cars]

Thanks guys, I now have a few ideas where to start.

 

 

Oh I'm going to have so much fun this weekend!

[Rich_p 23]

Let us know how you get on!

 

This morning the light started to come on when the engine was under load and flashing in time with the indicators.

 

If you switched on the rear screen while the engine wasn't under load it would make the battery light go off. Turning it on while under load mad the light go mental!

 

(sorry to hijack a little but as the problems are so similar it seems to make sense to share things!)

[welshpug 1,657]

I really wouldn't use the car till you have fixed the issue Rich, it is not unknown for 306's to go up in smoke when electrical faults are ignored.

[Rich_p 23]

Funny you should mention that, his Mrs 306 did end up emitting smoke from the dash!

 

The plan is to get his car home from work today and get it sorted over the weekend.

[madspikes 41 1 Cars]

Pah

[sickomotorsport 4 2 Cars]

Hi, check the rear wiper motor relay, it's in the boot next to the wiper motor. I have had them before full of water causing some of the symptoms you're describing .

[madspikes 41 1 Cars]

The car has been driving totally mad!

 

 

So far - Earthling in engine bay looks fine. I've pulled the heater fan relay and it makes the problem easier to control. By this I mean, now if I use the wipers and manually park them, the random flashing stops. If I don’t park the, eg just let them do their thing, lots of random flashing. So I have a way of controlling the random-ness.

 

 

When the car is in its funny state, the central locking doesn’t work, and when you press the unlock on fob the front wipers move!

 

 

All very odd.

 

 

I did however manage to clear the fault and return the car to normal earlier. I put the keys in the ignition and pressed the alarm button on side of the steering column for a few seconds, and now everything works as it should!

 

 

Ahhh.. Stupid thing!

 

 

 

Clive.

 

[madspikes 41 1 Cars]

Found the problem. The earth no. 4 according the Haynes, had broken Off. It attaches just behind the top of the throttle pedal! Reattach and all is now good! Can now go back to progressing the 205!

 

Cluve