Earlier today I was installing some interior LED bulbs and popped open the fuse panel to troubleshoot something (ended up identifying the problem separately). I was surprised to see a disintegrated fuse so I pulled and replaced it.

According to a fuse diagram I found on another site, the 25A fuse in question is for the "Fuel Pump Relay 1" with the 25A fuse next to it responsible for "Fuel Pump 2 Relay". Only the Fuel Pump Relay 1 fuse was bad.

Car has been driving fine, no errors, etc. I didn't really drive it after replacing the fuse...just from my driveway to garage.

Any thoughts on what may have caused this and why it wasn't apparent until I physically inspected the fuse?

 

Interesting you posted this. 997.1 Turbo - 2007 - Tried to start car - would idle for 2-3 seconds and shut down. Tried several times. Recalled reading that our cars have 2 fuel pumps. Decided to try and disable FuelPump 1 (by removing the fuse - the one that you showed) - and shockingly - the car started and ran fine until I had the fuel pumps replaced. Fuse was fine, but Fuel Pump 1 had failed. There were NO errors...

So in your case, Fuel Pump 2 kicked in (as in my case) and the car ran fine.

My guess is that we have two fuel pumps for redundancy? From what I was told, the Fuel pumps come as a unit, so to replace one, you replace both.

Maybe that sheds some light on it. Lucky for you it was a cheap fuse...for me it was a tad bit more $$. Porsche parts...UGH! haha

Rich

 

Thanks for the reply but sorry to hear about your fuel pump. Still not sure what would cause my fuse to blow though...

And here I was hoping that replacing the fuse would double my fuel output and therefore double my power!!

 

Now that would be wild! 2x the power. Quick thought - since the fuse for FP1 burned out - maybe you have a problem with FP1 and now FP2 is doing all the work as in my case - and again - not throwing a CEL (as was the case with me). The simple test would be to remove the fuse for FP2...forcing the car to use FP1 - if everything is ok - then your question remains - but if the car won't run, then you know FP1 is the culprit.

All the best.

RD

 

I'd rather not know!

All I know is I replaced the fuse and car works fine. However, I'll have to see if the fuse is still good...hopefully it didn't pop as well!

PS: How much did the fuel pump replacements run?

 

with parts/labor at dealer - was about $1,500, maybe $2k - don't remember exactly - but I do remember crying a bit...but then I put the hammer down...and forgot all about it!

 

Just curious, are either one of you running E85? How many miles?


Thanks,

 

No E85, GIAC Tune, 48K miles

 

This is just crazy then. 48K with a burnt fuse? Did you check the pump to see if it happened to be seized? If not, you may have a short somewhere.


I'll state the obvious, If the pumps have been replaced, keep an eye on this fuse.

 

Don't know how to check to see if the fuel pump(s) are seized or not...any tips?

Also, to be clear, I do not believe the fuel pumps have ever been replaced but can't be certain as I bought the car just 2000 miles ago.

 

Did the car have the tune prior to purchase? If so, you may want to inspect your fuel system.


With your setup, not many 997 guys upgrade the pumps but, you never know. Prior owner may have had "Big Plans." Don't mean to scare you but, just check to eliminate this.

 

thanks for the reply but sorry to hear about your fuel pump.

 

A few weeks ago when looking at the fuse box I noticed a burnt out 25A fuse (fuel pump 1). I replaced it but and have driven the car maybe 100 miles since. Checked again today and guess what...the replacement fuse popped...and, did a little damage to the plastic of the fuel pump 2 fuse right next to it. However, fuel pump 2 fuse itself is still fine.





No symptoms and car appears to be running just fine. I'll get an oil change in the next 1000 miles and will get it checked out. Very unusual and unsettling.

For now, I left the dead fuse in place (fuel pump 1). Call me crazy, but I am nervous about pulling the fuel pump 2 fuse (and replacing the fuel pump 1 fuse) to see what happens.

Anyone know where the fuel pump relays are located? And the fuel pumps themselves (are they in tank)?

**EDIT** I found this post that highlights where the relays are...somewhere in the driver's side footwell. Will take a look soon. Think it would make sense to order a new relay and see if that does the trick?

 

fuel pumps are in tank. one of the pumps is likely bad and drawing too much power and melting the fuses.

 

Thanks for the reply. I'll keep my fingers crossed that it is something simpler and will swap out the relays and also try and pull the fusebox forward to see if there are any pinched wires causing a short.

But in the end, I think you are probably right....

Just priced it out...OEM fuel pump is $583 (that by far the best price I found) but I believe I need to get 2. Unusual because diagram only shows 1. If it isn't something more simple like bad relay or wiring snag it looks like a $1500-$2000 job, as mentioned above by rdrozd