My older vans were heavily modified by me but the mods didn't affect their running or general operation -- stuff like the telescopic antenna mast, the RV battery set and charging circuit, sleeping bunk, roofbars, winch etc. were all transplanted from one van to the next as the original van wore out or rusted out under me. What I should have done was to drop a chunk of cash on something newer and more reliable, did all the mods I wanted to that and used it for several years afterwards with the expectation that when I got in it and turned the key it would start and go rather than every morning being a new adventure in fault diagnosis and rectification. I ended up spending the cash and more trying to keep something that was basically worn out on the road and I spent several hundred hours of my own time fixing it too (usually in the rain or snow...)