Where is fuse 22?

[TWork]

To make a long story short, I'm doing a MSD install. I'm not getting spark and I don't have battery voltage at terminal 15 of the six pin connector. According to the Bentley (page 280-9) 15 gets power from fuse 22 in main fuse box. I've looked at the fuse box table (971-2) and can't locate fuse 22. Anyone know where it is?

Thanks in advance,

T.

[jorian]

As there are only 21 fuses in the front (main) panel I would guess the fuse your looking for would be located in the engine compartment panel. Wheres' Warren when you need him?

[TWork]

Thanks Jorian. I thought that it might be in the rear, but according to the Bentley, none of those are ignition related. However, I had spare fuses, so I change all three in the engine bay, and it made no difference.

T.

[jorian]

See Bentley page 280-7.

If battery voltage is not present, there is either a fault in wire between terminal 15 and ignition switch, in ignition switch itself or in wiring from battery to ignition switch. Check ignition coil fuse. (#8 fuse in #1 [center] panel or # 11 fuse from right to left)

[TWork]

Jorian --

I wonder if there's variation in the Bentley manuals. My books doesn't say anything about "check ignition coil fuse." I did change fuse #11 with no change.

Anyone have suggestions on how to get power back to terminal 15 on the 6-pin connector that goes to the CDI box?

T.

[patkeefe]

Man, I hope you find 22. I was looking for 23 this afternoon (heater fan blower, 78 SC). I hope 23 is next to 22.

[TWork]

Pat --

I'm pretty sure the heater blower fan is the middle of the three fuses in the engine bay.

T.

[Randy Blaylock]

Strongly recommend you run a dedicated and fused power circuit to the MSD box, with good high strand count wire, minimum 12 ga, 10 ga possibly depending upon the run. They draw approximately 1 amp per 1000 revs. Doesn't sound like a lot, but most old 911s wiring is getting a little corroded and has extra resistance, you don't want to overload a circuit and cause other issues. Unless you're just looking for a switched 12V source to turn on the box, that's a different matter of course.

[TWork]

Randy, I'm looking for a switched 12v source to turn on the box. I already have the 12v dedicated source.

T.

[patkeefe]

Thanks, T:
Be nice to get the fan running. It's a bit damp and chilly here at Watkins Glen. I don't have any fuses in two of those three spots, and couldn't see the yellow/black wire coming from there (according to Bentley)
Pat
Also, I think the bottom fuse in that three fuse block powers the ignition system. I had a post a while back which Warren pretty much explained the power sources in. I'll post if I can find it.

[patkeefe]

Did I kill my plug wires?

[TWork]

Thanks Pat, I'll take a look.

[RickM]

As mentioned, perhaps the rear fuse block: 1985 Carrera Fuse & Relay layout reference

[Mysterytrain]

22,23,24 are the fuses in the rear of the car

[TWork]

Okay, I'll take another look back there.

Thanks,

T.

[randywebb]

It's wierd they would say "main fuse box" if in the rear - see the intial post. A factory schematic will sort it all out.

[TWork]

That's the thing Randy, it definitely reads, "fuse 22 in the main fuse box...." And, not sure why ignition wouldn't be listed as one of the items that runs through the rear panel in the fuse listings in section 970 of the manual.

T.

[patkeefe]

Another reason to think that too much Porsche engineering was done at the brauhaus

[randywebb]

Yes - and I just realized... it has to do with the electrical system! So like everything else electrical on these cars... it is bound to be screwed up.

[RickM]

Here's the code:

5 Amp = Yellow
8 Amp = White
16 Amp = Red
25 Amp = Blue


Don't know if this will help but here's the fuse config for an '85 Carrera (Yellow, rear fuse appears to be for the Heater fan relay):