Electrical Issues with VFM

Dear Kent, I have been running my 240D on your 2 tank conversion for a month or so (and it works PERFECTLY by the way) but the other day all of a sudden the electrical system quit turning on. The switches do not light or work, the fuse for the key'd power source is not blown and I hear the VFM relay engage but no power seems to be going to the electrical components...well some power but it barely registers on a voltmeter.So no power goes to/through the fuses it seems. I am not an expert at electrical systems but do you have any suggestions for things that I should do or test? Do I need to get a new relay?? Can a relay "kind of" work but not totally? I am generally able to troubleshoot problems but this one has me stumped. Thanks. Sincerely, Drew Etheridge

Forums

SVO Fuel Conversion Specific Aid

Taxonomy upgrade extras

SVO/WVO

Questions and Answers

Chassis Model Number

W123

electrical testing

Drew, check the yellow wire coming out of the relay and going into the fuse holder. Make sure it is not loose. Also check the black wire from the relay to ground. Make sure that connection is tight as we;;. Do you have tight clean contacts between the VFM brakcets and the body. If it is not a bad ground then it may be a fault relay. We have replacements on our website in twin paks.

At this point...

Well Kent I read your first/second post and I started trying to be very methodical about understanding what was going on. I began by testing the main F50A fuse. It looked ok and it seemed to have no resistance. I next began looking at the blue wires first connected to the relay then heading out the yellow wire to the fuse manager making sure that power was present at every step. However whenever I placed a fuse in the FuseBoss the power magically stopped flowing from the blue wire no matter what I did. Also I regrounded the black wires directly to the chasis. Well after beating my head trying to understand how power could stop flowing I did all the same tests bypassing the relay and found that the main blue power line did the same thing if connected directly to the fuseboss. (Obviously I was like "THIS IS CRAZY") So I looked back at the main F50A fuse and simply bypassed it and everything magically worked again. Soo it seems that the main fuse is somewhat tempermental and would (I guess) heat up or distort once power was flowing but if I waited a second it would reset and I could test power flowing again until I reconnected it with the circuit. All in all this was a learning experience for me but my question is can I get a replacement fuse from an auto store?? Should I stick to using the same kind/rating of fuse?? Thanks for the tips. Have you seen anything like this before? Take care. -Drew

Main fuse issues

Drew, I have not seen any issues with the fuse itself. I have seen problems when the wire connections to the fuse are not tight enough. You should be able to get a replacement fuse 40 - 50 amp at auto parts or auto radio store. If you can find anything we can send you one. Kent

So its figured out...

As it turns out it really just was the 50A fuse that was the problem. It probably was the direct connection to the actual fuse that was off but it is worked out now. I don't think figuring out electrical issues will ever be a problem again since I have looked into every tiny aspect of the VFM. Thanks for your suggestions and quick reply Kent. Sincerely, Drew

Congrats... good job!

Drew, way to stick with it and work your way through the problem. Electrical gremlins are the most difficult thing to diagnose and solving them can be time consumming and painful (I speak from experience). Now you can tackle any electrical issue! Kent