PLEASE HELP! I've killed my 521.

[mcdatsun]

Please forgive me. I'm sure I've done something very dumb. I have successfully wired up stereos before in an 86 sentra, an 88 micra, an 82 720, and an 83 Lada.

 

 

Bear with the back story, I just want to explain as best I can what happened.

 

 

Ok here's the story. Truck was running great, semi-daily-driver. Decided to install stock radio (bought from the 510 realm). Got the stereo wired as follows: Power wire (the blue one in the photo) to the top 8mm bolt on the ignition coil (there was already a wire run from there through the fire wall and going nowhere. Figured the PO had a stereo wired that way? Checked it's voltage and it was ~12V with the ignition at the on position, 0V when off). The truck has no antenna, so that was left disconnected. I added a ground wire connected where the antenna goes into the radio and grounded to a bolt under the dash. I connected the speakers, plugged in my iPod (had the radio modded to play an iPod, that's the white wire in the photo, the speaker wire is taped to the top.) and it worked great until I started the engine and then I got the engine amplified and played through my speakers. Figured this is because the power wire was hooked to the coil?

Next I tried wiring through the lights (not ideal I know, but just wanted to see if the engine noise would go away). Wired the power up to the wire powering the little under hood bulb that comes on with the hood open (before the switch.) Again it worked, but now was very staticy and very quiet. Figured not enough Voltage or current or whatever to run stereo.

 

 

 

 

AND THEN IT HAPPENED. I touched the power wire to the battery positive directly with the engine off; beautiful loud and clear sound! So I connected the power wire to the battery, so I could start the engine and see if I got the engine noise through the speaker. I turned the key and POW, a big spark right at the battery and the truck (Gus) was dead. No lights, no horn no nothin'. I checked the fuses, all good. After about 10 mins of softly sobbing I turned the lights on again and they're back and at full brightness. Turn the key, maybe a half turn of the starter click, dead. No lights, no horn no nuthin. !0 mins later lights and horn are back. That's where I am now.

 

Any one have any ideas????

 

Anything?

 

 

[thisismatt]

Did you check the main connections at the battery?

[Wide14u]

Did you check the main connections at the battery?

 

this is what i was thinking

[mcdatsun]

this is what i was thinking

[mcdatsun]

Yes. I disconnected the stereo wire from the battery, tightened the battery connections, but same thing.

[thisismatt]

Do you have the crappy screw clamp terminals? Take pics of the battery connection...

[mcdatsun]

I'll do that now.

 

 

 

[datsunaholic]

I'm going to go out on a limb and say you have those aftermarket battery clamps that sandwich the bare wires in a clamp, rather than the original type molded clamps? In all your loosening and tightening the inevitable corrosion finally formed an insulating layer. Take the clamp apart and clean the wires.

 

If that's not it, clean the battery terminals and the terminal ends. Also check the positive wire that DOESN"T go to the starter, wherever it next connects as that's a potential bad connection too.

[mcdatsun]

Ok, so I feel like an idiot, but a happy idiot!

 

Here are the connections

 

 

 

Re-checked and re-tightened the battery connections and voila! He fired right up.

 

Reconnected the stereo to the battery, and it's good. Shitty oic, I know but that red wire is the stereo power.

 

 

I know you can't hear it but this is a '72 Datsun playing an iPod through a stock radio. Sounds great!

 

 

And heres a oic of happy Gus.

 

 

Thanks guys!

[mcdatsun]

Oh, and I know I need to find a proper place to hook up that power wire, but now I can sleep tonight!

[Laecaon]

Pull power for cigarette lighter? Also find a source that comes on with accessory, not just at ignition.

[mcdatsun]

Yeah, I've always used the lighter before, but unfortunately the lighter is not connected. The ignition switch is different than what I am used to. It has on and ignition to the right (clockwise) of off, and then a position to the left of off, I guess that is the accessory position?

[Wide14u]

i am glad you got it going

[H5WAGON]

I might have to get one of those, my radio tray is not cut....:D no radio at the moment....just the L-series hum.

 

I like the socket location for the input...;)

[mcdatsun]

Thanks, there were a bunch of holes down there already, and that one was the perfect size. Nice and out of the way. Still haven't had a chance to figure out a better place for the power wire, but hopefully tomorrow.

[josh817]

Ignition switch order:

Acc-off-run-start

 

Position to the left of off is accessory. Hook a meter to it with the battery conencted. Turn the switch to the accessory position and hopefully it reads 12 volts. Then turn the switch to ignition/run and it should read 12v again. The schematic for the 521 shows that the accessory wire powers a factory option clock so it MAY have 12v even when off.

 

You should have 5 wires coming from the ignition switch. 2 for ignition (black/white and black/red), 1 for the starter (black/yellow), 1 for 12v from the battery (fat white), and the accesory (blue, no stripe I believe).

 

The cig lighter and the map light behind the seat above the rear window should be hooked to the same fuse which is hot all the time regardless of key position, if that's the route you want to go.