BushidoB 0 Posted August 10 Hello I'm currently learning about the looms in my cortina (Mk3 '71). I'd like to rewire down the road. I'm getting confused on how the regulator is set up. If someone could kindly share their knowledge (and patience), that would be hugely appreciated. I've added some pics in case it helps. (I'm assuming this is the voltage regulator, let me know if not!!). Diagrams I've seen show the regulator is part of the lights loom, and not in the charging loom. My alternator has 3 wires. I was expecting these to be an exciter (leading to the ignition switch), positive cable (connecting directly to the battery) and voltage regulator wire (also circles back to the battery for voltage monitoring). But it seems my basic alternator knowledge isn't in sync with reality. Out of the two red wires coming out of the alternator, is it a case one connects to the battery and the other the regulator? Then all power is generally sourced via the regulator (or at least for the lights)? Though it was better to ask, than to take things apart and run continuity tests. Quote Share this post Link to post Share on other sites
John Mack 286 Posted August 10 The regulator will be part of the alternator, the 2 red wires will connect and become 1 in the loom. Small blue wire will come from ignition via battery warning light. Whilst I don’t have a mk3, I’m thinking that what you think is a regulator is maybe a relay for the headlights? Quote Share this post Link to post Share on other sites
sheffieldcortinacentre 610 Posted August 10 As said the two red wires join just inside the loom & then go to the battery ( the regulator is inside the alternator). Only prefacelift ohv engined cars with a dynamo have an external regulator box. The blue wire is the "exciter" & goes via the ignition light to the switch ( if this doesn't come on with ignition then the alternator won't charge). The box mounted on inner wing on a MK3 is the headlight relay. Quote Share this post Link to post Share on other sites
BushidoB 0 Posted August 10 Thank you so much. Now it all makes sense. The lights loom diagram labelled it a regulator, which confused me. Much appreciated. Quote Share this post Link to post Share on other sites
sheffieldcortinacentre 610 Posted August 10 Glad I could help. Quote Share this post Link to post Share on other sites
