Fuse Box

[s6otty]

Could anyone help me with some fuse box Connections please. Car has been trimmed, some cables removed, I wired it several years ago, and poof, I can't remember!

In particular what cable, or cable colour to to Connector "O" and "N".

Also, am I correct in thinking the 2 Browns from the alternator are jointed under the dash, and go to the fuse box and battery to complete the charging circuit.

My fuse box (behind seat) is now fed directly from the battery (in boot). I'm trying to remove any redundancy, and thinking to complete the charging circuit by way of Alternator direct to Starter Motor.

Thanks in advance, and thanks for the info I've found so far thanks to posts.

Scott

[Belle427]

When I moved my battery to boot I ran a 50 mm squared cable to starter terminal and then connected alternator there too.
Some choose to run another cable up front for ground but I chose to keep it short and add a ground to chassis at rear.
Can't help with the fusebox wiring but member Steve D here may be along shortly with his fantastic diagrams.

[Steve_D]

The normal route is battery positive, 80 amp fuse, 2 heavy brown wires to terminals 'L'.
I don't believe there are any wires directly connected to 'N' & 'O' but they connect internally to 'L' so are permanent live.

Pm if you want my circuit diagrams.

Steve

[s6otty]

Hi Steve,

Thanks for the info. I have 2 boxes here, and neither N or O
connect to the permanent live main incomer by meter! My wiring runs from the alternator to the starter, then back into the car/fuse box, is this normal in your experience? Do you if the two main heavy browns are the ones that are in connectors under the dash top?

Thanks

Scott

[Belle427]

The 2 heavy gauge browns as Steve says go from an 80 amp fuse to the fusebox, they don’t go under the dash top.

[s6otty]

Morning Belle.

Mine seems really odd. There is no 80/100 Amp Fuse anywhere! (There is now, is the boot next to the battery) Its a 93 Pre-Serp.

I have 2 Browns from the Alternator linked to the Main Starter Cable, and then two linked back from the Starter, to 2 Connectors below the dash top, which then I assume should/would go to the Fusebox. Which kind of makes sense.

My fuse box is behind the passenger seat, the car has been trimmed, and they have had the box out, to some extent. I have routed 2 new cables from the battery in the boot (again fused), with the intention of powering the fuse box from there. I have the 2 large brown cables, but were convinced they were connected incorrectly in the fuse box. (All discovered due to a dead short somewhere upon cranking with is taking main fuses out!)

My original plan was to remove the two large browns, as I have a new feed now, but also have smaller browns in the same crimp, which I could do with tracing. All made much more difficult due to the car now being trimmed (Easy when it was bare) and trying to hunt down the short.

Appreciate your time.

Scott

[Belle427]

Some photos may help if you struggle to identify things.

[Steve_D]

s6otty said:

........In particular what cable, or cable colour to to Connector "O" and "N".

Also, am I correct in thinking the 2 Browns from the alternator are jointed under the dash, and go to the fuse box and battery to complete the charging circuit.

My fuse box (behind seat) is now fed directly from the battery (in boot). I'm trying to remove any redundancy, and thinking to complete the charging circuit by way of Alternator direct to Starter Motor.........

Just been back and looked again and found what I told you was wrong..sorry.

Terminal N does not have a wire to it. Internally it connects through to the front of the ‘box and is one of the posts with a thread in it. These 2 posts are the mount for a maxi fuse in other non TVR applications.

Terminal O has (on my car) 2x brown permanent live wires to it. Internally it connects to relay 10 (not used by TVR) and Fuse 13 which is the supply for the fuel pump relay and the alarm/immobiliser.

The 2 brown wires from the alternator output go to the starter. On later cars they go via a 100amp fuse mounted to the underside of the engine mount.

The 2 Brown wires feeding the fusebox (on most Chim/Griff) come direct from battery via an 80amp fuse.

Steve

[s6otty]

Thanks Steve,

I can probably sort it from that. Interesting about the Fuse Pump Supply, I have an issue there, so I can probably kill 2 birds with one stone, hopefully.

Scott

[wuckfitracing]

It`s not unusual as 1993 Pre serps did not have the fuse. Mine doesn`t either.

[s6otty]

Progress! All I have left is these 2, the fuse box is fed separately direct from the battery. These are live when unplugged, but I can’t find where they go. I am assuming O, and the Main Incomer (Is it L/.) along side the fees from the battery.

No fuel pump was a bad relay, note to self, check the easy stuff first!

Edited by s6otty on Monday 21st November 09:02

[Polly Grigora]

Yes, main positive from battery connects to L 30

A link from L 30 to O gives fuel pump

If those browns are still live with nothing connected to the L 30 terminals they will likely be coming from the starter solenoid main positive or a master switch up front