View single post by Esprit2
 Posted: 02-07-2016 07:44 am
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Joined: 05-01-2005
Location: Minneapolis, Minnesota USA
Posts: 338
NigelK wrote:
OK so the red / white ignition wire should be attached to the diagonally mounted spade terminal NOT to the smaller spade terminal marked "IGN". Confusing, but there you are. (Snip)... It's not really all that confusing once you understand the real meaning of 'IGN'. When the White-Red wire from the ignition switch energizes the solenoid, it also closes a second internal contact that sends 12 volts (full system voltage) to the smaller 'IGN' spade terminal. The attached wire feeds that voltage to the IGNition coil's (+) terminal. That by-passes the ballast resistor in order to feed higher voltage to the coil for a hotter spark during engine start. The hot spark only lasts as long as the starter is operated, so the coil doesn't over-heat. 'IGN' does not mean 'from' the ignition 'switch', it means 'TO' the ignition 'coil'.
NigelK wrote:
Anyway, the original reason for all this fuss was me installing headlight relays. These have reduced the voltage drop (cf. if the headlight circuit is all routed through the headlight switch) from 14.5-17% down to 5.6-7.1%, so I should have noticeably brighter lights. (Snip)... That's all well and good, and others have done similar mods. However, keep in mind that running a direct power feed to the headlights by-passes a significant power draw around whatever voltmeter/ ammeter the car may have (any car, not just JH), so the gauge will never monitor the power drawn by the lights. So when you look at the gauge, mentally add some for the lights. How much? I don't know, it's your circuit. Get a handle on it.

If a short, or some other serious failure ever develops in the lighting circuit, you'll get no warning from the instruments.

I'm not saying that's good or bad, just get your head around it and be alert for other symptoms that might give you a warning.

Tim Engel

Last edited on 02-07-2016 07:52 am by Esprit2