melted fuse holder above brake reservoir

Hello, I have a 98 jetta. CEL came on, glow plug heater circuit A indicated. Vehicle ran fine when parked. I checked all the plugs and they have the same resistance (.5). I replaced the harness as it was in bad shape and also replaced the fuel injector lines. Put everything together and the car would not start. I started looking for the fuses and found one with a larger fuse held in with allen head screws right above the brake resevoir. it did not pop and melted the housing. is the the fuse for the glow plugs? The car did start and ran finally after some coaxing. cel has not come back on yet. is it possible the removal of the fuel lines caused a hard start or did i short something and have no glow plug action?

Coolant glow plugs fuse. Clean the contacts and get a new fuse. It seems like hard starting related to the fuel line removal.

thanks, I went out this morning and started the car no problem. I did a vent job also, thanks for all the info and help.