20A Engine Fuse Blowing
 

Hi everyone,

I'm looking for any advice! My 15A engine fuse keeps blowing when I drive. It happened once on the highway going 100kph, and then on a freeway going 80kph. It doesn't seem to happen at lower speeds, but that might just be coincidence. Has anyone had this problem before?

Diagnostics I've tried:
- It will start and idle when I put a 10A fuse in place of the 15A. I drove it like this for a short distance on residential roads without issues.
- I limped it home (about 40km) on a 25A fuse the time it blew on the highway because that was all I had on me, but I took a different route that let me stay under 70kph.
- I did a visual inspection of the wires leading to the fuse box and relays under the steering wheel area inside the car, checking for pinched wires or loose grounds.

Relevant car history:
- Engine rebuild 500km ago - runs super well (except when it stops running). The car itself has 68000 km.
- Before doing the rebuild, I drove the car for 6 months or so daily without any problems. The blown fuses all happened recently and pretty close together, once before the rebuild and twice after.
- A/C, compressor, and rats nest deleted. I taped up the spare wires carefully and tucked them away.
- New spark plugs installed, but the ignitors and plug wires are original.
- It sat for 3 or 4 days outside (Canadian winter ftw) and I had to charge the battery before it started. Could just be from the cold, because after that it sat for a few days in the garage and it started up fine.
- Currently has a Carter electric fuel pump (pretty sure it's a carter p4070).
- It had an issue where the holley electric pump on it stopped working, but I'm pretty sure that was just a bad pump because I was actually able to fix it (only after I'd purchased and installed the Carter, of course).

I'm pretty stumped and I've never been good at the electrical side of things. Any help appreciated!

Roland

You'll need to investigate what circuits are on that fuse. My seat of the pants guess is the fuel pump.