635 to 535 fuse box swap....Update (archive)

Well, thanks to access to the diagrams, I can conclude that the late 635 to 535 swap is NOT a direct one-for-one swap. The 635's electrics are much less "precarious like a prom dress" than the 535's, in that the 635 have more circuits with less of a load on each one.

The late 635 has 30 active circuits counting the power window breaker.

The 535 has 18 circuits including the power window breaker.

Now, can it be used? Yes. But the circuit mapping would be custom and you'd have to make your own schematic or you'd have to do some "downstream" circuit splitting (putting the sunroof and rear defog on their own circuits, for example) to match the 635's box.

It would be entirely possible to wire up the 635's box to be a blade-fused version of the 535 box, with all but the fuel pump and main relay INSIDE the box. The relays are the "mini" relays, but it's possible to score those out almost any eurocar in the salvage yards.

I'm going to diagram out a 535 to 635 circuit conversion to see if I can do it (noting locations of splices, etc) but it seems more a matter of principle than practicality.

Bottom Line: It's easier to replace the 535's box and just use Ox-Gard grease and fresh fuses than it is to swap in a 635 box.

Brandon

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