

| Subject: | Re: headlights on with ignition on! |
| From: | David Marshall |
| Date: | Fri, 14 Dec 2007 15:16:59 -0800 |
In Canada, starting October 1, 1989 Day Time Running lights were mandatory on all new vehicles sold. Normally there is no relays in your light circuit so this would rule out a bad relay. Canadian and Scandinavian T3s used a relay for DTRLs. The DTRLs were the low beam circuit. It is documented in the Bentley manual on how it was done. Pulling the relay results in no DTRLs. For those who want to add the circuit, it is quite neat. A simple 30-85-86-87 relay is used with the following pinouts: 30 12V constant 85 12V switched 86 High beam circuit 87 Low beam circuit Basically for a relay to turn on, you need 12V across 85 and 86. So with the high beam circuit off - there is some resistance in the bulb filament but not enough to prevent the relay from "seeing" ground, so with the high beams off and the ignition turned on, the relay triggers. As soon as the user goes from low beam to high beam the high beam circuit goes to 12V and the difference across the relay is now zero and the relay goes off, thus preventing both the low and high beams to be on at the same time. David Marshall http://www.hasenwerk.ca http://www.fastforward.ca Box 4153, Quesnel BC, Canada V2J 3J2 On Fri, December 14, 2007 13:29, robert feller wrote: > Is there a common hack out there that I'm not familar with with someone > can > wire the headlights to be on any time the ignition is on? Or could this be > a > bad relay? I've seen high beems on when they shouldn't be with my Saabs. > > Again, got a 96 syncro that is newer to me and just noticed that the > headlights are always on with the ignition! May want to get this back to > normal when I do the relay/bulb upgrade in a couple of weeks. > > -- > Shawn Feller > Ohio > www.carboncow.com >
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