Hi All,
Thought I would give an update on my adventures with the DC/DC Converter. While waiting for the replacement to arrive, and having seen that that original one seems to have "dried out" fully, I decided to re-fit it, just to see how it would work. The results, I think, have been positive. It seems to be working well, although I have only managed to cover around 100 miles since it was fitted, but all in wet, or very wet conditions (and salt covered roads). So far I have not experienced any isolation errors, the converter cutting out, or indeed staying active when the bike is keyed off.
It would seem that moisture/water can indeed make it's way into the converter, the most likely route being between the mating faces of the connector housings, and from there through the space for the connector pins. It doesn't look to be getting it via the base plate securing bolts, as the threaded holes all appear to be blind. The good news is that this ingress seems to be reversible, drying out appears to work, and without any damage, to this one at least. Unfortunately, I can't be sure that corrosion hasn't started inside the converter, especially since it's possible road salt has also made it's way inside. This may eventually lead to a complete failure, but for now it seems to be ok.
I believe the original application of dielectric grease in the Zero factory may have been insufficient, as it appeared to be only present on the terminals themselves. To try and get a more waterproof installation, I also applied grease to the connector housing on the converter before inserting the plug. The result was somewhat messy, but has, I believe, coated the mating surfaces, and created a better barrier to ingress. The grease I used seems to be a thicker variety, and hopefully will resist wash off much better too.
I had hoped to run the Isolation test on the MBB console, but unfortunately it appears to need level 2 access, and I don't have the password for that. The BMS Data is showing Isolation resistances of between 227 and 347 kOhms, with the least Isolated cell varying between 1 and 2. I think these may be lower than normal, but don't seem to be low enough to trigger an error. I may run it again with the DC/DC converter disconnected to see what, if any, difference this makes, or since the replacement converter has finally arrived, I may try it to see if it performs any better.
It seems, for the moment, the original converter is not quite ready for the junk yard, but when it does decide it's time to go, at least now I have a replacement ready! I do wonder, though, how many converters were deemed to have failed in a similar fashion to this, but simply needed a bit of time in a warmer environment to rejuvenate them...
Ulster Zero