The car is showing an intermittent isolation fault for the HV system attached to the aux water heater. Dealer wants to replace the heater and the harness to (front to back along the chassis above the battery pack. This is going to be a heavy labor bill if we have them do it. They said the connector was corroded. I am going to check the connector myself and maybe hit it with some electronics connector cleaner and see if that makes a difference.
#4 is the cable, the aux flow heater is the gray item just above it.
#1 is the heater. It's easy enough to access. I could do it myself.
Are they being overly conservative in wanting to replace the harness as well? I feel they're trying to cover as many bases as possible in one move. But I'm not convinced it's completely necessary. Especially as the fault is intermittent. And only popped up after they replaced the fuel pressure sensor in the gas tank last week. Any i3 people here?
I want my wife to trade it on a leftover Bolt.
It's the bmw dealer. Of course they are going to blitzkrieg the parts cannon on it to avoid the comeback.
Personally I'd hit the connectors with some electrical connector cleaner then some dielectric grease and see... just out some time and a smidge of product.
In reply to Ranger50 :
This is my thought. Going to try this before I let them loose on it.
Jcake72
New Reader
3/5/25 12:50 a.m.
In reply to vwcorvette (Forum Supporter) :
Hibi was wondering if cleaning fixed it or had them change the cable thanks
Many automakers refuse to sanction wiring repairs on HV systems (or airbag systems) and I don't blame them. Terminals to repair the connector may simply not even be available. If the terminals are corroded, I'd replace rather than try to clean them. Terminals are fragile enough as it is, corrosion weakening them further is grounds for replacement IMO.
The terminals in the heater may simply be gone, too, necessitating a heater. If the heater connection was sealed, the corrosion may have been due to the heater having failed, leaking into the connector. Waterproof works both ways, and this would also mean that the wiring harness was full of coolant. (I've had to replace computers and modules due to damage from power steering fluid and from washer fluid, due to waterproof connectors and capillary action)
