The below chart illustrates not only my battery and charging paths, but it shows the electrical bus routes... More detail on the buses is in the relevant loom articles, but as there is overlap with this 'Battery & Charging' article, I thought I'd give it a mention here.

The busses are: one for 12v switched, one for 12v live, and one for gnd which is in addition to the engine bay grounding point for the main loom (10 (L8)) bunch of gnd wires.

Also, as I went the Ford route, and as my battery and charging setup is different to the LS configuration, I didn't need to use some of the GD loom wirings as some things came with direct connections to other 'things' e.g. engine sensors to gauges... 

This is my master sheet and it contains everything stemming from the battery, and this is how things transpired:

Power Cables: Assuming I wouldn’t get what I specifically wanted from anywhere, I decided to make my own cables out of 25 mm2 x 170 Amp cable. This would ensure the cable runs and terminals were neat and tidy, and one thing I was particular about was the orientation of the terminal ends.

Comment: Try going into a car accessory shop and asking for a 35 cm length of 25 mm2 x 170 Amp rated cable, black, with 10 mm ring terminals on each end, each being 90out of phase with respect to each other and with the flat bit facing the vertical on the kerbside side, and horizontal on the chassis side... And no, I didn’t... And I had no intention of doing so to see what reaction I would get.

Ring Terminal Connections: Tried soldering and blow-torching but these methods didn’t work for me. The solder just ran out of the little hole, and there was melted and toasted plastic everywhere. 

So it was over to plan “B” and that was, crimping. A much neater job and I did put some heat shrink on the ends to further neaten things up.

I also sourced the correct size ring terminals for what I had to do. A small detail but it had to be right. It really was so important to get a good solid conductive connection.  

Terminals sizes used:

  • 10 mm ring terminal (earth and main power cable to the battery posts)
  •   8 mm ring terminal (starter terminal)
  •   6 mm ring terminal (alternator “B” terminal)

Battery Cubbyhole: As my battery tray is under the wheel arch in its own little cubbyhole with the water-filled heater heat exchanger directly above it I needed to ensure the battery terminals were properly protected against potential water spray. So I went for the brass screw-type and associated covers from CBS.


Alternator: I have a GM 10SI “one-wire-hook-up” alternator, so I thought I’d write something about how this alternator type fits in with my grand scheme of things.

Wiring up was straightforward; a single cable to the “B” [battery] terminal on the back of the alternator and one to the starter motor and job dun’... Not quite!

I had an issue with the ignition warning light. On a GD LS setup, it’s just plug-&-Play to the dashboard loom via the engine plug; that being the ign’ warning light (NY and N, L14 wires.)  But, as I imported my alternator from the USA, I had to wire up my ignition “dummy light” [US terminology] directly from the alternator’s auxiliary spade terminal 1R. This, to one side of the ign’ warning light and a 12v switched feed is to the other side.

A simple job but there was a problem... I couldn’t get it to function as it was supposed to.

Then, after an age of research and troubleshooting, I discovered the internal voltage regulator was specific to the US market, so this one had no output to feed an ign warning light as expected.

The theory is: A 12v switched feed to the bulb [engine not running] would provide the necessary voltage differential to keep the bulb lit [when the ign’ is on], and would equalise the differential voltage when the engine was running, therefore the bulb would extinguish.

Totally mind-boggled me for ages, but I got it sorted in the end. I changed the voltage regulator for a UK one that was configured for how it needed to function.

Alternator Connections:

    • 25 mm2 x 170 Amp cable
    • 1R Terminal: Connected to Ign warning light(s)
    • 2F Terminal: Connected to 12v switched ignition

Now I have three ignition warning lights:

    1. On the dashboard (LED): Standard warning light
    2. Starter Button (LED): The Pilgrim Motorsport ‘Cobra’ starter button has an integral LED that lights up when the ignition is on and goes off when the engine is running. This looks really good and functions as a regular ignition warning light
    3. In the engine bay (LED): I needed an electrical load for the Pilgrim 'Cobra' starter LED light; so rather than having a regular bulb sit behind the dashboard shining away meaninglessly, I decided to put an additional ignition light in the engine bay. No 'real' practical reason for this but it serves as an additional awareness feature when looking under the bonnet. And I have to admit it proved quite a useful feature

Master Cut-Off Switch

I had a positioning concern regarding the Battery Isolator Cut-Off Switch. I bought one (the type with the red key) but couldn’t decide where to put it. It needed to be within easy reach and it needed to be protected from being accidentally knocked. So the only practical place was just underneath the dashboard on the right-hand side of the driver. So that's where it went... Anti-knock protection is provided by a piece of plastic drainpipe and there is plenty of room to reach it when strapped in.

An additional benefit of having the Battery Isolator in this position is, If I need to get behind the dashboard for any reason, the Isolator key has to be removed.

The way I’ve fixed the isolator is on a plate that is bolted to the under-tray retaining tabs on the steering column brace. So now it is not possible to have any power to anything behind the dashboard when rummaging around. Or conversely, you have to intentionally switch on the power to make things work when the dashboard or driver’s under-tray has been removed… A very good safety feature.

The main loom (L17 (11)) 50 Amp main feed wire is also connected to the isolation side of the switch. And in keeping with [power] cable management, I moved the ‘positive’ power post to the other side of the engine bay and used a distribution post to simultaneously feed the starter and alternator... I was always wary of the positive post being in too close proximity to the negative post.

Battery Charging & Conditioning

Been thinking about how to fit a remote charging point for ages but couldn't decide how to do it... Then I came across this wonderful piece of kit which fits the bill perfectly.

I Have a CTEK MXS 5.0 charger/conditioner, and low-and-behold they make a proper remote unit called a 'Comfort Indicator Panel' which is a proper plug-&-play unit... Halfords strikes again.

Fitted it just above the negative power post.

The operation is simple... When connected to the battery a green light blinks to indicate the battery is in good shape. If the battery needs charging an amber or red light blinks... So for anything except green you just plug in the charger... Simple.