Good morning everyone, I found this place as I'm having a strange problem with either my car, my caravan or the PeakPowerPack installed in there.
Background is: I am using the same Ford S-Max car since 4 years to tow a Knaus caravan with a Victron PeakPowerPack 40Ah installed to it. The PPP is connected to the switched power output of the car (line 15). For almost 4 years this worked just fine with no issues at all. The Ford has a factory-installed tow hitch and electrics, and it even monitors the power consumption of the trailer. Whenever the PPP was fully recharged on the go, I got a 15 seconds message in the car's display that the trailer battery does not charge anymore.
Now in 2024, things changed a bit: everything still works fine overall, meaning the PPP gets charged as before, but at the moment it is full, I won't get the informational display message anymore.
Instead, the engine error light will go on, and when reading the car's modules with my Ford-specific OBD2 scanner, I find exactly the SAME five errors again and again. That's one from the trailer module, one from anti-lock brakes, two from the engine module, and one from the steering control unit. Of these five errors, the steering module is indicating overvoltage of the power supply, and the brakes and one of the engine faults are indicating that one of their signals has exceeded their defined max ranges.
So to me as a half-professional (originally being a car engineer, but not working as such), it looks like there's some overvoltage in the system when the PPP charging shuts off. Question now is where to start looking to solve the problem? Trailer module? The alternator's voltage regulator? Or do you think that this could also be caused by an internal defect of the Peak Power Pack?
I have to add however that this car is known to be problematic while towing. In one German online forum for car topics I found 38(!!) others within ONE SINGLE single discussion thread getting random engine fault codes when towing a caravan, with usually no defects found at the car shop afterwards, and no faults coming up without their trailers in tow. So I think it's most definitely related to the car, it just seems to have a hidden electrical or electronical flaw with towing to some extent. This experience of 38 other owners in not finding the cause is also the reason why I'm hesitating to simply bring the car in for service. I don't want them to start to randomly replace expensive parts by new ones with the same problem after all. But then again, if it's simply a known problem with that type of car, then I don't understand why I didn't encounter these problems during the last four years? I guess the PPP has always behaved the same. So what part has "weared down" so much that it now started to throw these errors? Something needs to have changed, either the car, the PPP or any connection parameters. That's why I'm asking if it could be a problem with the PPP as well, maybe putting overvoltage on the charge line?
But second question: let's assume it is the car having a built-in problem with the trailer battery instantly stopping to charge: would there be any electrical way to "soften" this immediate interuption of the power draw down a bit (hoping that the car could then cope with it)?
On the next trip I will simply disconnect the charge line from the PPP, in order to hopefully avoid breaking down again, but the engineer in me still wants to SOLVE that problem and not just avoid it...
So thanks a lot for any ideas on this, it's very appreciated!
