Yaris 1.3 auto, 2002 strange electrical fault

[Garfeild]

Hi all
I had a strange electrical fault on my 2002 Yaris 1.3 auto, id just driven home and about 100 yards from my house, I had an electrical failure, the car kept on running but all the dash lights, radio, auto gearbox indicator lights, brake lights , went out, and the power steering stopped working.
I parked up, went in to find my manual thinking a fuse had gone, but when I came out to the car, everything was working again.
I did have my speed camera detector and phone charger plugged in at the time, but I don’t think that would overload the electrical system.
I checked the battery this morning before going to work.
12.6v engine off
14.2v engine running
14.1v engine running, lights,radio etc etc on
Went to work today, no problem, came home, and it did it just as I parked up, didn’t notice until central locking didn’t work, checked, and again no dash lights, speedo, etc etc, I left it for 10 mins, went out and presto,all working again, only difference between going to work and coming back, was the lights were on half the journey home.
Anyone know what’s going on? could be a bit iffy if it’s happens again on the motorway.
TIA.

 

[Alec_t]

Sounds like a dodgy connection somewhere, perhaps due to corrosion on a car that old. Check in particular that all ground connections are good.

 

[Garfeild]

Would that only show after the car had been driven for a while though?
I would have thought that would show intermittent yes but could be after it’s done 300 yards or 30 miles, its never done it on a short journey my drive to work is about 30 miles

 

[Burnerman]

Did you notice if the speedo stopped working at the time, Mr. G?
Although your battery test seems to imply that everything is just fine, how old is the battery?
John

 

[Alec_t]

Would that only show after the car had been driven for a while though?

Possibly, if expansion (or vibration?) played a part.

 

[Garfeild]

Did you notice if the speedo stopped working at the time, Mr. G?
Although your battery test seems to imply that everything is just fine, how old is the battery?
John

Yes it’s a digital speedo, and rev counter all went off.
engine carried on running and headlights stayed on, no dash lights, including speedo etc, no interior lights, no brake lights or indicators.
Don’t know how old the battery is, I got the car about 3 months ago, but it’s not been used too much until I started a new job and now it’s used every day.

 

[Burnerman]

Dashboard problems on these aren’t unknown and if the speedo packs in the PAS doesn’t get a signal so it thinks the car has stopped.
Anyway, before we get stuck in, can you rig up your multimeter to see what happens during your drive.....again the symptoms are typical of a sudden voltage drop too.
John

 

[Garfeild]

Dashboard problems on these aren’t unknown and if the speedo packs in the PAS doesn’t get a signal so it thinks the car has stopped.
Anyway, before we get stuck in, can you rig up your multimeter to see what happens during your drive.....again the symptoms are typical of a sudden voltage drop too.
John

I’ll have to rig up a couple of wires into the cabin and connect the meter to them, I may not be able to get this done until the weekend, I was going to check all the Earth connections I could find, clean the battery terminals, etc.
So I’ll have to report back.
Would the speedo fault cause all the other interior lights and indicators Etc to stop working?

 

[Burnerman]

The dashboard is quite a complex device dull of circuitry and it relies on inputs from various sensors and modules and can cause all sorts of issues - but a speedo fault wouldn’t cause light failure.
Do all of your checks on the battery terminals and earth straps first, and also the voltage readings if you can.
Hopefully it will be a battery issue - a voltage drop always causes the PAS to pack in.
John

 

[Garfeild]

No problem today bad weather, lights wipers etc on on way home, car behaved perfectly, how am I going to find out what’s causing the fault if it’s so intermittent?

 

[Burnerman]

Very difficult, I agree.....how can you find a fault that isn’t there?
You’ll have to wait until it happens again I’m afraid. Is the alternator the original, do you know?
John

 

[Garfeild]

I suspect the alternator is original, it certainly doesn’t look new that’s for sure, I don’t know if there’s a date stamp on the battery either, and to cap it all my old multimeter has died as well FFS
I’ll still clean everything I can find at the weekend, and buy a new meter.
Thanks for your help

 

[Garfeild]

Ok, so I have a different problem this morning, the car worked perfectly yesterday when I went shopping, but I’ve gone out this morning to start doing my checks, and, the car unlocked ok, but it’s gone straight into it’s fault, no power inside the car, no dash, no radio etc etc, like a fuse has gone, main problem is I can’t move it as it won’t come out of park, as I assume that’s electrical as well, I’m still going to clean all connections, and check fuses etc, meanwhile, any suggestions as to what I check next?

 

[Burnerman]

Check the battery voltage, then connect a charger. Leave it a while and see if it comes back to life.
John

 

[Harry Bloomfield]

Ok, so I have a different problem this morning, the car worked perfectly yesterday when I went shopping, but I’ve gone out this morning to start doing my checks, and, the car unlocked ok, but it’s gone straight into it’s fault, no power inside the car, no dash, no radio etc etc, like a fuse has gone, main problem is I can’t move it as it won’t come out of park, as I assume that’s electrical as well, I’m still going to clean all connections, and check fuses etc, meanwhile, any suggestions as to what I check next?

Ignoring your previous issue, your latest one suggests a bad connection to the battery/ battery to car/ bad main earth, or in fact your battery is completely flat. Yes, do clean and check main connections as you planned. Is this a diesel or a petrol?