Q1 - Why are there two coax inputs / cables running to the stock Toyota radio, a thick one (perhaps antenna) and a thin one??

I am looking at the Alpine CDA-9886 which I assume needs only one coax input for the antenna, and I assume do NOT need to keep the Toyota Amp.

Thanks

 

pretty sure ones for the am just use the bigger one for fm

 

Thanks for the quick reply. Might that have something to do with why some people say they don't get AM reception with aftermarket radios?

If one is for AM, where does it come from, since I don't think they both run from the same whip antenna.

 

the second smaller antenna is NOT for am reception.

the thicker antenna cable is the primary antenna, the one on your fender. the smaller antenna is a diversity antenna, most likely located in your passenger rear window, looks like a defroster element.

for the best example as to how a diversity antenna works, have you ever pulled up to a stop light and the radio reception seems to fuzz out just a little? and when you pull forward another foot or so the reception comes back. the diversity antenna is supposed to eliminate that, giving another path for the signal to travel into your radio, the second antenna in your glass.

in 14 years of stereo installation, I have seen 1 aftermarket head unit with diversity capability, if memory serves it was a sony, about 10 years ago. also, no manufacturer has settled on a universal diversity antenna plug, so every car manufacturer is different. even the sony just had 2 female antenna plugs labeled main and sub, the toyota diversity antenna would not plug into it.

 

Thanks for the detailed explanation.

I'm going with an Aline CDA-9886 and I'll just wrap up and forget about the diversity antenna lead.