Electrical Issues

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Recently I was faced with several power issues with my car and I thought it would be a good idea to trickle charge my battery because I hadn't driven the car for almost 2 weeks. Like an idiot, I reversed polarity on the battery when reconnecting the terminals and hence a lot of problems.

Long story short, I had a new alternator fitted on the advice of a breakdown engineer. But the auto mechanic who assisted in the installation of the alternator said it was my main fuse which had blown, the 120 Amp, which powers the alternator. In fact he said that it was unnecessary for me to have the alternator fitted in the first place. This was the reason he said that my car kept breaking down.

Anyway that's by the by really although I was annoyed at the breakdown engineer from the AA for what should have been a routine test that he failed to perform. After the fuse was changed the car ran fine but the electrics remain damaged. The dashboard does not illuminate, the stereo doesn't work and neither does the dash cam.
Most importantly though, the back lights do not work which mean I cannot take it on the road.

The other day I tested all the fuses in the car and found that all of them had continuity. I then tested the voltage and almost every function was ruining below 12 volts. On average arround 11.75 which obviously is too low.

I am not very experienced with mechanics at all but I like to try and fix things for myself when I can. I feel now that I am a little out of my depth. I used various AI programs for advice and it seems now that this maybe something to do with wiring and various other parts that I have no experience of dealing with before. I recently tried fitting a crankshaft sensor but in the end I had to enlist the services of a professional to do the job correctly.

Now Grok is telling me to check ground connections, BCM module and fuseboard input, but doesn't properly explain how I should go about doing this.

Vehicle in question is a Kia Rio 2005 mk2. 39000 miles on the clock.

Any thoughts or suggestions would be gratefully appreciated.

Rob.
 
Hellish bad luck here, Rob.
Control modules don’t like reversed polarity, try contacting ECU Testing of Heanor for advise here.
However, your voltage is too low so get the battery fully charged so it shows around 13v and see if anything has come back to life.
Be lucky
John
 
Disconnect the battery overnight

Re connect tomorrow and see if anything is different.

Charge the battery too whilst disconnected
 
Recently I was faced with several power issues with my car and I thought it would be a good idea to trickle charge my battery because I hadn't driven the car for almost 2 weeks. Like an idiot, I reversed polarity on the battery when reconnecting the terminals and hence a lot of problems
Don’t modern cars have reverse polarity protection?

Don’t modern chargers have reverse polarity protection?
.

Long story short, I had a new alternator fitted on the advice of a breakdown engineer.
I hope it wasn’t after the mistake you made and was offered as a solution to amend the damage done.
In fact he said that it was unnecessary for me to have the alternator fitted in the first place.
So did I.

Why did he install one then?
This was the reason he said that my car kept breaking down.
What were the initial problems you were experiencing?
Anyway that's by the by really although I was annoyed at the breakdown engineer from the AA for what should have been a routine test that he failed to perform. After the fuse was changed the car ran fine but the electrics remain damaged. The dashboard does not illuminate, the stereo doesn't work and neither does the dash cam.
Can bus related?
Most importantly though, the back lights do not work which mean I cannot take it on the road.
Further confirmation it could be related to CAN.
The other day I tested all the fuses in the car and found that all of them had continuity. I then tested the voltage and almost every function was ruining below 12 volts. On average arround 11.75 which obviously is too low.

I am not very experienced with mechanics at all but I like to try and fix things for myself when I can. I feel now that I am a little out of my depth. I used various AI programs for advice and it seems now that this maybe something to do with wiring and various other parts that I have no experience of dealing with before. I recently tried fitting a crankshaft sensor but in the end I had to enlist the services of a professional to do the job correctly.

Now Grok is telling me to check ground connections, BCM module and fuseboard input, but doesn't properly explain how I should go about doing this.

Vehicle in question is a Kia Rio 2005 mk2. 39000 miles on the clock.

Any thoughts or suggestions would be gratefully appreciated.

Rob.
Take the advice, given above, and disconnect the battery over night. Failing that, you may need to check voltages at the main control modules.

If you have a multimeter you can always check resistance at the OBD connector and see if the terminating resistors are intact.
 
Hellish bad luck here, Rob.
Control modules don’t like reversed polarity, try contacting ECU Testing of Heanor for advise here.
However, your voltage is too low so get the battery fully charged so it shows around 13v and see if anything has come back to life.
Be lucky
John
I trickle charged the battery to 13.26v but it hasn't made any difference to the readings.
 
Look at fuses. Quite likely 1 covers dash, and accessories. Possibly brake light switch too.

Remove and replace the fuse even if it's still unblown, but turn it round, renew it's contacts
 
I then tested the voltage and almost every function was ruining below 12 volts. On average arround 11.75 which obviously is too low.

Was that measured, engine running, or not. 11.75v could be normal, at the end of long wires, due to volts drop along the wires. If you measure at the battery terminals, you will be measuring the full voltage.
The dashboard does not illuminate, the stereo doesn't work and neither does the dash cam.

Modern electronics, do not suffer reversed polarity well. From your description of the engine being able to start and run, it suggests the engine ECU has survived, but your lighting ECU, and radio have been wrecked. You might be able to get replacements from a scrap vehicle, but you would need to research whether the parts might need to be customised, to your vehicles ID.

You are wasting your time, using AI, for a problem like this.
 
I can't remember if the engine was running or not to be honest. You're absolutely right about AI. I think it works to a point but when it advised me to pull out a relay fuse with ignition on I knew that something wasn't right...
 
I think it works to a point but when it advised me to pull out a relay fuse with ignition on I knew that something wasn't right...

AI relies on reading peoples previous answers to similar problems. Some people will suggest, taking an angle grinder to it, as a joke. AI cannot tell the difference between a helpful reply, and a flippant one.
 
AI relies on reading peoples previous answers to similar problems. Some people will suggest, taking an angle grinder to it, as a joke. AI cannot tell the difference between a helpful reply, and a flippant one.
Just curious to know what would happen if I pulled out a relay fuse with the ignition on
I didn't test continuity on the relay fuses but I'm going to do that now.
AI also advised me to test voltage while on the relay fuses with the engine running, but that's impossible as the pins are not exposed..
 
Look at fuses. Quite likely 1 covers dash, and accessories. Possibly brake light switch too.

Remove and replace the fuse even if it's still unblown, but turn it round, renew it's contacts
I did replace the fuses for the lights which had continuity anyway so there was no suggestion that they were blown. The fuses visibly seemed intact, nothing broken and no sign of burning. The replacement fuses made no difference unfortunately.
 
Don’t modern cars have reverse polarity protection?

Don’t modern chargers have reverse polarity protection?

I hope it wasn’t after the mistake you made and was offered as a solution to amend the damage done.

So did I.

Why did he install one then?

What were the initial problems you were experiencing?

Can bus related?

Further confirmation it could be related to CAN.

Take the advice, given above, and disconnect the battery over night. Failing that, you may need to check voltages at the main control modules.

If you have a multimeter you can always check resistance at the OBD connector and see if the terminating resistors are intact.
The car is 20 years old. I have no idea if it has polarity protection... I might just Google it.

The AA guy to be fair, I'm not sure if he was aware of what I had done by reversing polarity. Other people have suggested that it's not such a big deal

The mechanic was simply acting on my instructions as I assumed the AA guy knew what he was talking about.At the end he had to call out his mate an auto electrician as the battery was still not holding charge. It didn't take him longer than about 10 minutes to spot the blown fuse.

I don't know how to check resistance at the OBD connector. I have the auto engineer coming out tomorrow. Only thing I haven't checked is continuity in the relay fuses so I'm going to do that shortly. AI also advised me to check voltage on the relay fuses but that would seem to be impossible as the pins are not exposed like the regular fuses.
 
Not sure who or what you mean by auto engineer but I'd suggest your money would be better spent going direct to an auto electrician

Many garages, mechs will do some basic testing and after that call in auto electrician and pass their bill on to you. Go direct, cut out the middleman
 
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