Newbie loses mentor; need some

Hi, First post greenhorn. I sort of started a project with my electronics mentor and best bud, that we intended for our trucks. But he's taken seriously ill. I'd love to get it started just to show him something before he's not here to show anymore.
I'll try to explain the beginning part I'm stumped on. The plan was to use the power to the reverse lights to trigger a relay. But he was never able to explain how this would happen only when the truck was put into reverse. How was the relay supposed to ignore the power sent to the reverse lights when you put an automatic transmission into drive. Everyone's seen the reverse lights flash when a driver slides the gearshift across from P to D.

If this is in the wrong forum I apologize. If this has been covered somewhere already please point me in the right direction. If I need to supply more information I'm more than glad to do so.

Jeff

Rev to relay 86, NEG to 85, in at 87 out at 30.
This assumes reverse feed is POS (+).


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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Thanks Howie. That was embarrassingly simple.

If you need to avoid the shifting issue. Just use a time delay in the trigger circuit.10 seconds should do it.


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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !