While doing some research on the problem and waiting for parts, I decided to pull out the headlamps to work on them.
Removed from the truck, they are easier to work on.
One diagnostic task, is to look for unusual current loads in the system. First stop was the headlamps, looking for evidence that some clown hat put in 100w bulbs or some other nonsense. What I found was just that sort of… nonsense. Luckily they didn’t over-watt the lamps, but at some point someone put in those inane blue headlamps (but they looks so cool.. no!). I didn’t detect this because the blue one was burned out. All the better. A pair of 55w H7 replacements will be procured.
With the lamps out, I’m going to do some sanding and polishing on them to return some of the original clarity. Right now, they are much better after that first attempt, but they are not where I want them to be.
Some sanding with 800, 1500 and 2000 grit wet-sand, then a light polish with Mequires… they don’t look too bad. But I know they can be better.
To fully diagnose the electrical gremlins that are plaguing me, getting unrestricted access to all the grounds and the glow plug relay pack, goes a long way. So.. I started to take apart the front bodywork.
Neat Sprinter tidbit… this is the air intake (other side does not have this vent). This is a true cold-air intake. Air box is right there behind the headlamp (or where it would normally reside). Also, it’s possible to get at the grounds behind and under the headlamp with those parts out of the way.
After re-checking and cleaning all the ground table locations, and there are plenty, I focused on the glow plug relay. Typically the relay itself does not fair hideously, but what more commonly happens is a glow plug (or 5) will short out, causing a heavy drain (more than 20A) on the electrical system. 5 glow plugs shorted out is over 100A of current and would easily kill the 90A stock alternator.
Based on information obtained from the various Sprinter forums, I fabricated (term used loosely) a jumper cable that can be used to test glow plugs for a shorted condition.
Because the simplest place to test it from the glow plug relay harness, I unplued the 5 wire connector (1 for each GP).
On one end of the wire is a spade connector that is screwed to the battery. I didn’t want to have to mess with holding both ends of the wire. On the other end, I crimped on a small finish nail. This is useful when testing the glow plugs from the glow plug harness.
Poking the wire into each of these connectors here, I was able to determine that none of the 5 glow plugs are exhibiting the signs of a short. When I bought the vehicle the owner assured me the glow plugs had all be replaced in the last 2 years. It seems very likely that was a truthy statement. All good in this arena. But that also means I must continue to look for the cause of my woes.
Since the bumper on this thing was in pretty bad cosmetic shape, I decided to remove it too for a little refurbishing at some point down the road.
This little LED light really came in handy when working on things under the beast. Takes 3 C-cells and provides a pretty good amount of light, even if they LEDs are not the wide angle type. It was much easier than the conventional flashlights (due to built-in stand) and not hot and tangly like an old-school drop light (I really do have a heavy dislike for them).
To keep the new battery charged up while I sorted out this mess, I re-purposed one of the 25′ charging cables from the MV Agusta, added the charging lugs to the Sprinter’s battery, and plugged it into this gem I picked up last month. Love having the computerized 1.25 AMP computer controlled charger.
With the Glow Plugs eliminated as the likely cause of my troubles.. the next step is more drastic… checking the turbo system and fuel system components. Good times ahead.