Radio problems + alarm ...

[SpeedyG]

Are Toyota's OEM radios mapped with the ECU ???

So here goes,

I have an 89 4Runner V6 and the PO changed the radio and installed an alarm which I "think" were connected since the truck won't start since I removed the old radio.

Anyway, all the plugs are the same for the radio.

I unplugged the radio from my 88 parts 4Runner and plugged it in my 89 .... doesn't work but it did in my 88.

Question is : is the radio mapped with a truck ?

Is there a special code or something for this ?

My radio is an OEM Toyota.

Thanks

 

[wolfgang]

No - should be NO connection between the radio and vehicle starting/running. There ar OEM theft deterrent radios but if batter/radio is disconnect they will simply display SEC or HELP when max unlock attempts exceeded. SDound like you blew a fuse, tripped a switch or disconnected a wire.

 

[SpeedyG]

No - should be NO connection between the radio and vehicle starting/running. There ar OEM theft deterrent radios but if batter/radio is disconnect they will simply display SEC or HELP when max unlock attempts exceeded. SDound like you blew a fuse, tripped a switch or disconnected a wire.

All my wires are connected (I've checked and double-checked).

I have power in the plug that goes in the radio. I have 12 Volts which I checked with my multimeter.

However, I noticed that I have 12 Volts between the C & G plugs (+12 Volt Ignition Wire & Ground) BUT I don't have anything between the D & G plugs (12 Volt Battery Wire & Ground). See pic.

Should I have juice between the last two ? If so, that should be a fuse, right ?

Else, .... wtf

 

[SpeedyG]

Forgot the pic

 

[wolfgang]

Don't have wiring schematic handy - that "D" termial is constant voltage for the radio's preset button memory. So even if no voltage there the radio should come on from the ignition battery connection- you'd just have to scan for a local channel. I heard where on some years, owner will plug in a high draw item like a laptop into the cigarette lighter and next thing they know their radio and/or clock no longer work! In that case there isn't a visible fuse --- instead its a hidden inline fuse link just behind the hot wire plug in to the cigarette lighter. Can't see how it would affect vehicle starting though. Does engine not even turn over - or turn over (starter grind) but not start up. Checking all fuses, reseating them and the little relay boxes is good start. Some fuses can look good but doing a continuity/resistance check with your meter reveals blown fuse.