TJ3 1 #1 Posted August 7, 2020 I'm in the process of installing an electrical fuel pump in my 1990 520H, and of course other things. Thinking I may just rewire it. If so, what size wiring is used in the harness? 12, 14,...? Share this post Link to post Share on other sites
WHX?? 52,090 #2 Posted August 7, 2020 14 gauge is acceptable except for the charging circuit which should be 12 gauge. Battery cables should be 6 gauge. Share this post Link to post Share on other sites
TJ3 1 #3 Posted August 7, 2020 19 minutes ago, WHX24 said: 14 gauge is acceptable except for the charging circuit which should be 12 gauge. Battery cables should be 6 gauge. Thanks a bunch. Being really dumb, I assume 'Charging Circuit' means to and from the regulator, possibly small wires on the starter, and maybe the coil leads? Just wanting to order a bunch of wire in various colors. 1 Share this post Link to post Share on other sites
WHX?? 52,090 #4 Posted August 7, 2020 (edited) Charging would be from the regulator, I think it's a white wire through the nine pin to the 30 amp fuse. Also the red wire through the nine pin from the battery that goes to the 25 & 30 amp fuse should be 12 ga. Many times this is the sore spot on the engine connector so it's common to see these wires bypassed at the nine pin. also a sore spot at the 30 amp fuse on the fuse block. We've seen many a fuse blade melted off due to heat and corrosion here. The red wire feeding the ing. switch should be 12 also. This is from a 520 wiring diagram but should be similar. Let us know if you need a diagram for your tractor. Edited August 7, 2020 by WHX24 bad screen snip 1 Share this post Link to post Share on other sites
peter lena 9,330 #5 Posted August 7, 2020 while you are at it , if you want to , you can SPIRAL WRAP THOSE WIRES , i regularly use this to contain and prevent chafing and shorting issues. your wire source will probably have it in sizes and colors . also emphasis on grounding and dielectric grease at all contact areas. pete 1 Share this post Link to post Share on other sites
lynnmor 7,904 #6 Posted August 7, 2020 2 hours ago, TJ3 said: I'm in the process of installing an electrical fuel pump in my 1990 520H, and of course other things. Thinking I may just rewire it. If so, what size wiring is used in the harness? 12, 14,...? I hope you don't mean to rewire completely, that would be quite a project. Normally wires don't just go bad, they are damaged by humans, and the ends are damaged from neglect. 1 Share this post Link to post Share on other sites
