Noob Checking in from central texas

[jason rea]

Hello, I’ve surfed this forum for info for a couple years, and usually found what I was looking without posting.

So I am adding on some axillary reverse light to the wife’s car. I wired it up so it would come on automatically when she put the car in reverse. I also added a switch to allow her to manually turn them completely on or completely off. So right now the switch works for the on and off. But the auto function isn’t working yet. I think I’ve figured out why, but I need a part I can’t locate.
So how I have it wired –
I have a SPDT 12v relay that is normally closed.
Connected to it I have the new lights connected to 87,
ground Connected to 85,
fused power connected to 30,
and the center of the switch is connected to 86,
On one side of the switch is fused power.
The center of the switch goes to 86 on the relay.
and the other side of the switch goes to the tapped factory reverse wire for the signal.
I’ve double checked all my connections, and the lights work manually. So checking around with meter, I noticed the factory reverse wire when engaged only shows 7v, and after going through a one way diode(to prevent back feed) and getting all the way to the switch, it only shows 5v to 5.5v. Unfortunately that’s not enough to activate the coil/switch inside the relay. So I’m looking for a SPDT relay that can function on a 12v system, but be triggered by only 4.5v. Unfortunately all the electronical supply stores from when I was a kid no long exist, at least not here in central Texas. Anybody got an idea where I can find the right relay?
Thank You

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