High RPM voltage rising

[Ewazix]

Couple of thoughts ....... you mentioned blowing fused/components so it's a voltage surge rather than spike, if voltage surges after the seats have been on for a bit it's probably because they are switching out once warm, the alternator has been producing a high current and is reducing output too slowly, causing a brief surge. I'd have suspected the regulator/alternator, but since you have swapped out the reg' a bad earth or connection (battery, block, alt' or ECU, or seats maybe?)

Chances are surges are occurring with other high draw components like heated glass but not high enough to trip warnings, if so other damaged components will start to pop-up so I wouldn't just leave the seats off and hope TBH.

 

[mjennings23]

Couple of thoughts ....... you mentioned blowing fused/components so it's a voltage surge rather than spike, if voltage surges after the seats have been on for a bit it's probably because they are switching out once warm, the alternator has been producing a high current and is reducing output too slowly, causing a brief surge. I'd have suspected the regulator/alternator, but since you have swapped out the reg' a bad earth or connection (battery, block, alt' or ECU, or seats maybe?)

Chances are surges are occurring with other high draw components like heated glass but not high enough to trip warnings, if so other damaged components will start to pop-up so I wouldn't just leave the seats off and hope TBH.

Thanks for the input.

To clear it up, the voltage reported jumps to around 18v in one specific condition right now; heated seats are on and engine rpm exceeds 6k.

While, as John says, the alternator was changed quite recently, I'm still going to try a replacement this weekend, if for nothing else than to eliminate it from the probability. Monitoring voltages with any other electricals in any condition seems to maintain a steady 14v however.

 

[mjennings23]

So, collected a replacement alternator to try out. Also trying to do some digging and find a diagram showing ground points throughout the chassis to check, but it seems impossible to find in any simple diagram.

I believe there's a fair few near the steering column for the modules behind the dash, so will check these and also the B+ cable as best I can. Doesn't seem like issues that point to a bad cable but I'm just trying to eliminate possibles.

If anyone can point me in the direction of other ground points please do!

 

[mjennings23]

Seems the alternator fitted has gone bad unfortunately. Only noticeable under high electric load, but the replacement works perfectly.

Hopefully that's the end of the issue, I have a new Bosch part ordered from Germany which should be here in a couple of weeks.

Might also explain why I was never particularly impressed with brightness of the xenon bulbs...

 

[mjennings23]

And for a final update, new Bosch unit fitted and all seems perfect. Hopefully that's the end of it, but now I think my front headlight leveling sensor is going bad too... Bloody cars

 

[Ducklakeview]

And for a final update, new Bosch unit fitted and all seems perfect. Hopefully that's the end of it, but now I think my front headlight leveling sensor is going bad too... Bloody cars

Did you raise the car to swap the alternator? If so the arm on the front sensor may have folded over on itself and will be giving the wrong readings. Worth a check?

Mike

 

[mjennings23]

And for a final update, new Bosch unit fitted and all seems perfect. Hopefully that's the end of it, but now I think my front headlight leveling sensor is going bad too... Bloody cars

Did you raise the car to swap the alternator? If so the arm on the front sensor may have folded over on itself and will be giving the wrong readings. Worth a check?

Mike

Last time it was up on jack stands was the steering swap, so it could have happened then perhaps. It's been flashing on and off for a while.

The strange thing is INPA reads the code as short circuit to ground on the front levelling sensor sometimes, and others as open circuit on the same, yet when I turn the dipped beams on the warning light goes off. I'll have a play with it and see if moving it causes the lights to move up/down as expected.