Indicated voltage and actual voltage are not the same on an X. Unfortunately.
For a variety of reasons the voltmeter will almost always read low. The volt meter reads the voltage from a source that has many other feeds which are relatively high draws. Among them the lights, the wipers etc.
Using a voltmeter across the battery with the engine running will tell you what your actual voltage is, you can turn on the wipers, lights and so on to see if there is actually any drop in voltage at the battery and then have a look at the voltmeter to see the effect on the gauge of those elements running versus the actual charging behavior.
The brown wire mod, if needed, will provide more power to those junctions but will not cure the resistance (carbon, wear on the contacts) that builds up over time in the ignition switch which reduces the voltage actually available to the accessories on the other side of the switch.
The brown wire mod will have added a non factory wire going from the battery (preferably about 10ga) that runs to the supply side of the ignition switch and the other to the multi wire feed to the fuse box. Both require either sistering a wire to an existing wire (the ignition switch) or in some cases redoing all the connections at the junction to then fuse box depending on the damage to the wire there. The additions tend to be pretty obvious.
In regards to you neighbor, be careful. If he is asking basic questions such as wire routing, I am a bit concerned as it is pretty obvious what happens as one can observe (with some difficulty admittedly) the ingress and egress of the wires into the vehicle structure as well as the route the alternator to starter wire follows. There is nothing more dangerous to an X than some well meaning individual with limited knowledge who “fixes” things. My apologies in advance for casting aspersions on your neighbor.
Your car has a Bosch alternator so the brush set is easily replaced. One can change the wire from the alternator to the starter to a larger gauge wire but it isn’t needed unless there is damage to the wire itself, changing it certainly won’t hurt anything if the new wire is properly built.
The late cars, like yours, have significantly better wiring than the earlier cars. Adding another wire to the ignition switch supply and another wire to the junction which feeds the fuse box can improve matters greatly but there are other things which would be even better: relays with their own fused supply of electricity.
There are three projects which will have a much bigger and better effect on the electrical on your car. The first two deal with day to day voltage draws and the last is more about an internmittent use. The first two are to put relays on the wipers and relays on the low beams (your car has a relay on the high beams already), this can be done as a plug and play or by wiring in relays permanently. These mods have been covered many times and if you are interested I would be happy to dredge up those threads for you. The third is to install a starter relay, this takes the starter load off the switch and puts it onto an easily replaced relay.
There is a fourth thing one could do, which is somewhat controversial but one I advocate, is installing a load reduction relay. This relay is installed on the load side of the ignition switch and switches the load from all the when running electrical systems off the ignition switch so that the switch is only carrying the load of turning the relays on and off. This one is a bit more involved to do and a number of forum members have done it.
So why relay these things? To save the switches from the heat that will eventually cause them to fail and to remove the resistance across the switch so that there is a more reliable, higher voltage supply of electricity to those accessories. Thus the lights will be brighter, the wipers will go faster and the starter will always spin and not just click. The other major benefits are that the ignition switch is much less likely to fail, the headlight switch (which is nearly unobtanium) will not see nearly as much load and the wiper switch will be out of the loop (they rarely fail).
Hope that helps.
Karl
