Some background info:
So I have an 05 s2000. I've owned it for a year. I bought it just like it is. It has a full exhaust. Also, I have amp/sub setup. I've had no issues with it until now. My alternator fuse keeps getting blown. I've changed the battery. I've changed the alternator. I've changed the fuse. It will run well for 2-3 weeks. Then, my dash lights start to dim, headlights turn off, and eventually car dies. I'll change the fuse and it'll run again for a few weeks and die again. It's been really getting on my nerves. I've tried disconnecting the amp/sub from the battery; that hasn't helped. I've checked for bare wire; I couldn't find any bare wires. Idk what to do at this point. I want to find the source of this problem. Guys please help!! Any tips/suggestions are appreciated! Thanks

 

your fuse isnt blowing if those are the symptoms. a blown fuse is an on/off switch. nothing gradual about it. If you want to save some money while trouble shooting it, go get a circuit breaker. they are about 5 bucks and fit in the fuse slot.


ok.


troubleshooting. Look for ground wires that are loose. go through ALL of them. not just your stereo but ALL of them on the car. theres one under the dash by your left foot, the battery to chassis and a few others. check out the service manual for the locations. snug them all down.

second. make sure they are all there and that someone hasnt removed one thinking they know more than the engineers at honda. then report back to us.

 

What fuse? As I recall there a 100 amp fuse from the alternator? Is that one blowing? Most (all?) S2000 fuses are numbered.

-- Chuck

 

It is fuse #6 in the under dash fuse box that keeps getting burnt out. It's the alternator fuse.

 

Well the fuse is blowing because when I remove the fuse #6 after driving the car for a few weeks, the fuse is burnt. So I end up replacing it as a temp fix so I can drive to work.
I checked the ground under the dash and everything is where it's supposed to be. I'll have to check the other locations. But like I said before, I've owned the car for a year and I haven't done anything to it other than basic maintainence. So if someone were to remove a ground wire, I would have encountered this problem a long time ago not a year later

 

The #6 fuse controls more than just the alternator.

Air Control Solenoid Valve, Alternator, Charging System Light, Cruise Control Unit, Cruise Control Main Switch, ELD Unit, EVAP Bypass Solenoid Valve, EVAP Canister Vent Shut Valve, EVAP Canister Purge Valve, Primary and Secondary Heated Oxygen Sensors.

Do you have any other symptoms that might narrow it down? Try unplugging some of these items like the cruise control or the EVAP stuff and see if the fuse still blows?

 

if the fuse is burnt and not BLOWN. theres a difference....its an over voltage, i think. over current would pop the fuse, over voltage could be at the same amps if resistance went up.

check your alternator to ensure that its putting out 14v and not something crazy like 17. you might have a voltage regulator thats toast.

 

Fuse #6 in the shop manual protects the voltage regulator which is built into the alternator. But the chances of two bad alternators is pretty slim. Electrics get "burnt" when the get hot and amps, not volts, makes heat.

-- Chuck

 

if that weere true it would have blown the fuse not burnt it. also, if the voltage is higer than it should be it might mean that resistance has risen and current stayed the same.

thats why i lean towards a poor connection and not an over current. big resistance.


wonder if the wiring harness is chaffed somewhere or loose at the alternator giving a poor connection. I once had a 17volt reading from an alternator due to a loose connection at the alt. maybe look for rodent damage?

 

Not trying to sound like a smart ass but not sure what the difference between a blown fuse and a burnt fuse is. Sounds the same to me but what I'm pretty sure that it's a blown. The little metal piece inside is split in two