First timer needs help

[NoobInUtah]

I'm going to install a cheapo stereo in my '86 4Runner, it was stolen before I bought it, and I'm over my head.

My reciever is a Motorjoy GTO-740CD, very basic stuff. I'm not running an amp or changer.

The OEM harness was cut off, and the wires aren't any colors I recognized (Grey, White/Black, Blue, Blue/Yellow, Pink, Purple, Green, and Pale Green). A little testing with the fluke revealed that Grey is the switched power, and Blue/Yellow is constant power. Hooked those up, and ran the receiver to ground (same ground I used to ID the power wires), but I've got nothing when I turn the key.

Disregarding the speaker wires for now, the reciever has

White - panel light
Orange - power antenna (?)
Yellow - memory (constant power)
Black - ground
Red - switched power
Violet - telephone mute

Not using the phone mute, don't think I'm supposed to be using power antenna or panel light, am I? And if so, what do I splice it to?

Any help much appreciated. I know this is basic stuff, but I've been wrestling with it all day and getting nowhere.

[NoobInUtah]

Found this, so I guess I know I've got it wired right.

I don't know what could be wrong with the cars wiring, though. Defective reciever?

[mike49504]

1984-86 Toyota 4-Runner Stereo Wiring
Constant 12V+ Blue/Yellow or Blue/Black
Switched 12V+ Gray
Ground Brown
Illumination Green
Dimmer n/a
Antenna Right Front
Front Speakers 4" Dash
Left Front (+) Pink
Left Front (-) Purple
Right Front (+) Green
Right Front (-) Blue
Rear Speakers 5 1/4" Side Panels
Left Rear (+) Black
Left Rear (-) Yellow
Right Rear (+) Red
Right Rear

[NoobInUtah]

From the12v.com? That's what I hotlinked above, and how I've got it wired. Curious if there's any further troubleshooting I should be doing before I take it back the retailer.

[Perry Babin]

You need to use a multimeter to confirm that you have a good ground and 12v on the backup and memory wires.

[NoobInUtah]

Originally Posted by Perry Babin

You need to use a multimeter to confirm that you have a good ground and 12v on the backup and memory wires.

Originally Posted by NoobInUtah

A little testing with the fluke revealed that Grey is the switched power, and Blue/Yellow is constant power. Hooked those up, and ran the receiver to ground (same ground I used to ID the power wires), but I've got nothing when I turn the key.

Thanks, I've already verified the chassis ground and 12v at the power wires.

For troubleshooting purposes, do I risk any damage to the reciever if I bring my 12v straight off the battery, as long as I'm careful not to cause a short? I'm thinking about supplying 12v straight to the power and switched power wires, and going to engine ground, just to eliminate anything in the truck wiring as defective, but I'm nervous about bypassing the fuse box. Thoughts?

[NoobInUtah]

Mmm. Power leads on the reciever harness have black cases that look to hold inline fuses. Haven't checked those yet...

[Perry Babin]

When checking the voltage on the head unit, you should touch the pins of the connector where they enter the wiring harness plug that plugs into the back of the head unit.

I don't know anything about that radio but some pioneer head units had a fuse hiding behind the wiring harness plug and you had to remove the plug to see it.

[NoobInUtah]

No, no fuse there. I didn't realize there was bare copper there to check for power, so thanks for that... off to hook it up again.

[NoobInUtah]

When you've eliminated everything it's likely to be...

I swear on my mothers grave there was 12v constant power on the blue/yellow lead when I started. I'm sure there was, because that's how I found it before I looked up the wiring diagram. It sure as hell ain't there now, though. The switched wire (grey) is fine, comes right to 12 when I turn the key.

So. Bad wire, somewhere. I'm off to hunt for the answer, but does anybody know where that constant hot comes from? Fuse panel layout http://www.4crawler.com/4x4/4R_TechI...tml#Electrical]here[/url], but I don't see anything likely. I suppose I could fuse a new wire straight off the battery through the firewall, but that seems a little ghetto. Any ideas?