Keyless Entry - Aftermarket?

1998 Lumina sedan. Base model. Power locks. Power windows. Power mirrors. Power seat.

Vehicle is used. And original owner is no longer with us.

I am trying to add another keyless entry remote and I obtained a used factory one. I just need to program it. I have read all above and have not found the black/white wire in rear sidewall.

Looking at the two keyless door lock remotes that came with car, it appears that they are both aftermarket. Looks like the brand is DEI called Your VALET with a number RPN491.

So my questions are: Can the factory one work with the aftermarket ones? If not, then where do I obtain another aftermarket one? And has anyone heard of this brand: DEI?

Did they sell the 1998 Lumina with factory power locks WITHOUT a factory battery remote?

Thanks to all who read my post about the aftermarket keyless remote entry.

I found an 800 number for DEI. This company sells many remote starter modules. They still manufacturer remote keyless entry modules.

There is an automotive radio/alarm shop just down the street from where the Chevrolet dealership is where this 1998 Lumina was originally purchased new. They have no record of installing this but this is what they do. One remote had a dead battery, and they replaced the battery for free. No need to reprogam anything. Now both remotes work perfectly. If I need a replacement they can order one. About $50.00.

And no, this aftermarket keyless entry is not compatible with factory keyless remote.

All is well that ends well.