Johnny Versatile,
My siren didn't operate so I ordered new batteries thinking that I could just replace the batteries and everything would be fine. Here is a link to the batteries I purchased on eBay. https://www.ebay.com/itm/2x-Ni-MH-Bu...72.m2749.l2649

I took my siren apart and found, like everyone said, a circuit card ruined by the leaking old batteries. I just taped up the connector under the cowl and didn't install a siren. Car works fine without it. There are a lot of used sirens on sale on eBay but you could be buying a siren that may have a ruined circuit card.

Before you purchase any batteries take your siren apart, there is a procedure on the forum, and see if your circuit card is damaged. If so, a new siren costs around $140.00. Hope this info helps.