S197 Mustang SVA, IVA, Importation & Light Conversion Information

So, you have your car, you have all the parts, now you want to actually do the work. Expect it to take between one and two days to make a nice job of it. I have not bothered to note the colours of the cars wires feeding this and that, as if you are doing this job, I expect you are familiar enough with a 12v tester to be able to identify them anyway.

I am also not going to go into great detail about where you should route individual wires, you will find your own way that suits you.

Assuming you are performing the light conversion using Euro Tail Lights and Angel Eye Headlamps as I recommend (the easy way) on this site, it might be useful to do a double check of the things you are likely to need.

The vast majority of items can be had by mail order, the advertisers on this site will be as good a source as any.The internet tends to make suppliers of this kind of stuff quite competitive as they know you onlya mouse click away from another supplier who is maybe cheaper than them

Some people (on a V8) modify the front fog switch wiring to operate the rear fogs. I prefer to tamper with the original wiring as little as possible, so I fit a new switch. (V6 cars do not have a fog switch anyway so you have no choice but to fit a new one in that instance.)

You need an illuminated switch. It should be visible from the driving seat ideally in order to pass a test. I use an after market one and site it near the regular light switch.

Observe that one end has a silver stripe on it, that is to ensure you fit it the correct way around. It is imperative they are fitted the correct way round.

The diode goes between 1 and 5 on your Omron relay bases, bridging between the only feed from the SJB (being the light you have tapped from) and ground – with the black end of the diode going to the Nr 1 ground terminal. Put another way, black end to earth, silver stripeend to switching live from the light you tapped from.

The relays you need are low current devices. Do not use standard ‘automotive’ style relays. The average Automotive relay has a coil resistance of about 60-90 Ohms, where as a relay more suitable, will have a value of about 1000 Ohms. You really do need to put a back EMF protection diode across ANY relay coil connected to an ‘electronic’ output. This will minimize the back EMF voltage across the SJB* outputs. More on that on the diode article.

For the purposes of the light conversion detailed on this site, you don’t actually need a lighting diagram. However, in case you are modifying another part of your Mustang lighting wiring circuit, you can download from this page the S197 lighting wiring diagrams.

No significantly greater loads on any existing circuits is your aim. This is why you do not just link your back lights off your front ones, or a few months later you need a new SJB. This is what the relays you will be using are for, the existing circuits will switch the relays and the actual power will come from elsewhere thus bypassing the SJB.