GeoffCampbell
New member
Hi everyone, newbie here.
OK, this is a slightly weird problem. From the "no good deed goes unpunished" file, there's a lad locally has just passed his test, and he owns a 56 plate Punto 1.2 (presumably therefore a Mk 2, I'm not familiar with the model ranges?). This was sitting outside his house for a while, then the MoT and tax expired, so I said he could drop it into our yard to get it off the road while he sorted himself out.
Having a reasonably well equipped workshop here, and knowing my way around a car, I volunteered to fit a new battery and give the car a bit of a service, ready for him to get it MoT'd. The old battery was hosed, after it had been left to go flat a few times.
So, new battery in, start the car up, and find that the power steering has failed while it was sat idle. While investigating that, I found that there were none of the expected C100x power steering codes registered, but there were codes for P0500 Speed Sensor and P0560 System Voltage. Clear the codes, restart the car, and they come back again, so there's definitely a problem, not just a hangover from the old, knackered battery. I read that speed sensor problems can fox the power steering, so that's a useful avenue for future investigation.
Now the weirdness - measuring the voltage across the battery terminals, I found around 12.5v with the engine stopped, but then got 18.1v with the engine idling. Don't think I've ever seen that on a car with an alternator, in many years of tinkering. I have seen it on bikes at higher revs, they have very basic generators and simple regulators that can fail.
My immediate suspicion would be that the alternator has failed in some new and exciting fashion, but does anyone have any other ideas?
OK, this is a slightly weird problem. From the "no good deed goes unpunished" file, there's a lad locally has just passed his test, and he owns a 56 plate Punto 1.2 (presumably therefore a Mk 2, I'm not familiar with the model ranges?). This was sitting outside his house for a while, then the MoT and tax expired, so I said he could drop it into our yard to get it off the road while he sorted himself out.
Having a reasonably well equipped workshop here, and knowing my way around a car, I volunteered to fit a new battery and give the car a bit of a service, ready for him to get it MoT'd. The old battery was hosed, after it had been left to go flat a few times.
So, new battery in, start the car up, and find that the power steering has failed while it was sat idle. While investigating that, I found that there were none of the expected C100x power steering codes registered, but there were codes for P0500 Speed Sensor and P0560 System Voltage. Clear the codes, restart the car, and they come back again, so there's definitely a problem, not just a hangover from the old, knackered battery. I read that speed sensor problems can fox the power steering, so that's a useful avenue for future investigation.
Now the weirdness - measuring the voltage across the battery terminals, I found around 12.5v with the engine stopped, but then got 18.1v with the engine idling. Don't think I've ever seen that on a car with an alternator, in many years of tinkering. I have seen it on bikes at higher revs, they have very basic generators and simple regulators that can fail.
My immediate suspicion would be that the alternator has failed in some new and exciting fashion, but does anyone have any other ideas?
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