Speedtoys

Sorry to hear Rob. We didnt go, KNOWING we had a flatbed-timebomb luring in the our own fuel system, and opted to stay within earshot of civilization today.

Rob Edwards

I'm just glad it went TU in the right lane of I-210, just past an onramp. 20 miles up in the San Gabriels, out of cell phone range, coming to rest going uphill on a blind curve with no shoulder would have been suboptimal....

It occurs to me that I didn't check the inline fuse (black cube, wired to the + terminal) I installed for the 044 pump relay, under the battery cover. Duh. Will look at it when this frigging gymnastics meet is over.

borland

Rob,

In the photo, you have that red wire running through a bulkhead without a rubber grommet. That is not a good. Sure you have an inline fuse, but that won't ensure roadability. On the relay terminals, you should also shrink wrap insulate the blade connectors all the way to the tip.

Also, I see in your photo that you had another cable bundle (black/blue stripe) running through the bulkhead to the tranny area, where the grommet is not in place. If you coat the rubber grommet with dielectric grease, it will be much easier to reinstall.

Rob Edwards

Barry-

All good observations, this was during the 'snaking wires everywhere' phase, before the stroker was a running car. The power supply cable now has a grommet on it (though I should double check all my wiring for abrasions), and all the relay leads are shrinkwrapped. I think I managed to get that ABS harness grommet back in too, but that was a PITA, even with the transmission out of the car. Never thought to try dielectric grease as a lube. Good tip!

Rob Edwards

Glad I bothered to put a fuse in the line to the fuel pump relay, I managed to cook the bejesus out of it.... Perhaps I need to rethink where to get switched power for the sharkwoofer cooling fans.....

Something's not quite right here:


And REALLY not right here....

BC

Oh snap!

Tony

Bad fuse?

heinrich

Looks like 15A may be too high Rob. But, as Tony suggests, cheap HF fuses tend to do this as well.

borland

What's the other inline fuse in the photo being used for?

Radio Shack has some fuse holders rated at 30A for 12V system that you can use with your 15A fuse.

While your at it, you should brush your battery terminals with battery grease (dielectric grease). That will help eliminate any condensation there.

Rob Edwards

Might be a bad fuse, but it blew pretty spectacularly, that much heat has to have been a short, no? I am utterly electron challenged but I did move a bunch of wires around in the wheelwell this weekend. I made a power harness for the sharkwoofer cooling fans that piggybacks off terminals 30 and 85 on the 'extra' fuel pump relay. I thought I'd heat-shrunk the terminals well enough, but maybe not.

Barry, the other fuse holder is part of a pigtail harness for a battery tender. Wiil do on the dielectric grease. I don't have any- is all dielectric grease the same, or is there a preferred brand/flavor?

There are a few new wires in the wheelwell, after this weekend, I think I need to more carefully consider their routing :

jcorenman

Rob,

I am guessing either a cheap/defective fuse, or fuseholder. A direct short would have vaporized the fuse element (the Z-shaped wire) with minimal melting.

The fuse is melted from heat over time, from a high-resistance contact-- resistance multiplied by amps equals melted plastic, and the 044 pumps draw quite a few amps (hence the secondary relay and direct feed).

It was a great route, and we missed having you as a leader. And sorry about missing the turn, we wound up on Angeles Crest instead of Big Tujunga for the last leg down the mountain, a hazard of letting the inmates run the asylum. Traffic wasn't bad however, just a few death-wish motorcyclists. And only one Ka-chirp, somewhere behind us on Angeles Forest Road. ("Honey, that was BEHIND you, wrong pedal!").

Great drive, sorry you couldn't be there!!

Rob Edwards

Jim- Gotcha, that makes sense. I think I might have paid as much as $12 for a 10-pack of those fuse holders. What's a higher quality source for ATO/ATC inline fuse holders? Or is there a more elegant way to provide fused power in the spare tire well?


Glad you enjoyed the route! Did you like that northernmost portion of Angeles Forest, coming up out of Palmdale? It was pretty magical the morning I pre-ran it.

John Speake

What is the current rating of those fans, Rob ? It might be better for them to have their own dedicated feed/fuse/relay. Rather than runnig a fuse/holder near its rating when shared with the 044.

borland

Just looks like a bad fuse holder to me, but you should consider the current sources. Most multimeters have a current measurement setting. So, you might run some tests on the current draw for each component and try to find the total maximum current draw of all components on the fuse. Problem with this strategy is that the fuel pump draw depends on fuel demand, so taking current measurements would require some actual driving or dyno runs. Could be that the fuel pump has published current draw specifications from the manufacturer that you could use instead.

Most automotive supply stores sell battery grease in tubes or spray. It can also is sold with a battery terminal kit. The grease may include some colorant, but it just plain dielectric grease. You'll only need a very small amount, so if you already some on hand and a small brissel brush to spread it around, that's what you should use.

Rob Edwards

If one believes the current draw specs on an 044 pump from websites that don't include the word Bosch in the URL, max current draw is quoted to be either 13 or 15.5 amps. Probably part of my problem, right there....

The cooling fans on the SW2 draw 0.15A, so not much additional there.