She’s headed back to Marfa!
When working on the vehicle we noticed an intermittent loss of 12V power (this provides power to the lights, locks, gauges, etc.). It turned out to be a defective main fuse holder that would brake contact when jiggled or held in a certain way. We replaced this to make sure that didn’t happen again.
After seeing that the battery coolant level was low, we were concerned that it might be a leak. It’s also possible that there was an air bubble trapped in the lines that finally worked its way out, as well, but we needed to be sure.
After consulting with ZeroLabs, we used a scope to view the bottom of the battery pack from the access window. We ended up finding traces of coolant, not much, but enough to warrant further examination.
We removed the bottom of the battery box and found, thankfully, that there was no more coolant than what we saw. So, with the bottom off, we filled the coolant and ran the pumps for 24 hours and found no active leaks. We feel confident that the leak might have only been present during assembly of the pack and that the low coolant was due to an air bubble.
We did, however, find some condensation/moisture in one of the battery modules. This may have been present during assembly or repair of the pack in the past or it’s possible it was due to the coolant evaporation. We ended up removing the cover of the module, and drying it out with a fan for 24 hours and installed a dessicant pack to absorb whatever might be left in the air. Then we sealed it all back up.
The switch on the driver door for the passenger door window was inoperable. While we repaired the door locks, we figured out what parts were broken, ordered a new switch, and strengthened the design so it shouldn’t fail again.
We discovered that the door handles and locks were problematic. The automatic locking was unpredictable and the handles and locks would frequently get stuck.
We have some technicians with a lot of experience on old Ford door latches working here, so we put them on the case. They found that there were some installation errors, some fitment issues, and some broken parts causing all the issues. The tech went through both doors, adjusting, repairing, and replacing parts to get the doors to function smoothly and predictably.
Also, we found that one of the key-fobs seemed to be non-functional (possibly damaged) but the other one had a low battery. After replacing the battery, the automatic locks seem to operate properly and predictably.
Given that the symptom was that the vehicle ran out of charge unexpectedly, we decided to drive it through a complete discharge cycle to make sure nothing went wrong or that we didn’t experience the same issue. Fortunately, we did not - the truck drove as expected and depleted the battery in a linear fashion. We got about 125 miles of range with mixed driving.
We did, however, notice that the battery pack’s coolant level was abnormally low. We suspect a leak, but aren’t sure. From a safety perspective, we feel it’s necessary to confirm that this isn’t a hazardous leak in the battery pack.
With the new fuse installed and the Battery Management System cleared of all its faults, we were able to get the vehicle charging again. We let it do a full charge and periodically checked the battery cells as they were being charged to make sure they did not incur any damage after being discharged so low. Everything looked good and we now have a fully charged Bronco!
We found that the problem that prevented the truck from charging was a blown fuse for the on-board-charger. Before we just replaced the fuse, though, we needed to research the specifications for the charger and work with ZeroLabs to make sure the fuse was properly sized and there were no shorts or malfunctions that caused the fuse to blow.
In the end, we determined that the fuse was undersized for the potential current draw it could see. It probably worked when using certain chargers in the past, but it finally blew, likely when the vehicle was being charged after being completely discharged.
We were unable to charge or drive the vehicle, as expected, so we moved to diagnosing the issue. We were able to gain access to the Battery Management System so we can look at any of the error codes that may have been blocking the vehicle from driving or charging. Sure enough, we had a few and one in particular was preventing driving, but there was nothing preventing the vehicle from charging.
We cleared the codes and moved on to further diagnosis
The truck arrived today and we were able to roll it off the transporter and get it into the shop. We are going to do some diagnostics to determine what the current state of the vehicle is and then work with ZeroLabs to determine the best course of action