1987 GM, too hard to install unit!
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=34852
Printed Date: April 29, 2024 at 5:41 PM
Topic: 1987 GM, too hard to install unit!
Posted By: ed112
Subject: 1987 GM, too hard to install unit!
Date Posted: June 30, 2004 at 1:00 PM
Hi,
Im putting in a new CD player into a 87 GM, no amp or subs are being hooked up. The new head unit has:
* 8 wires for the speakers
* Ground, Ignition, Battery
* Illumination, Remote Trigger, Motor Antenna
The radio doesn't work at all when I turn on the ignition. The factory plug for this GM has only 11 wires (8 speaker wires, ground, ignition, battery).
Can someone please explain what I am doing wrong ? Does the illumination wire not being hooked up to anything have anything to do with it ? Or do I need to test with a multimeter each wire on the factory plug to see what is going wrong ?
I would appreciate anybodys advice on this installation because the car is a fossil
Replies:
Posted By: icu400
Date Posted: June 30, 2004 at 1:15 PM
illumination won't matter, remote won't matter since you have no amp, and I doubt you have a motor antenna
check a few things:
1) all wires not being used are wrapped up
2) no bare connections inside
3) fuse for the stereo
peace
Posted By: forbidden
Date Posted: June 30, 2004 at 1:40 PM
have a look at www.installdr.com to see if your vehicle and it's wiring plug is listed there. ------------- Top Secret, I can tell you but then my wife will kill me.
Posted By: kgerry
Date Posted: June 30, 2004 at 3:54 PM
you need to make sure the constant power is hooked up to that unit...this is not supplied thru the 3 plugs that stack on the back but thru the small 2 pin connector that is on the other side of the rear of the radio...the orange wire in that connector ( there should be an orange and a brown ) needs to see 12V constant or the radio wont work
-------------
Kevin Gerry
Certified Electronics Technician
MECP First Class Installer
Owner/Installer
Classic Car Audio
since 1979
Posted By: ed112
Date Posted: July 01, 2004 at 12:51 AM
Why isn't constant power supplied by the wire in one of the 3 plugs ? Why do you need to connect B+ to the orange wire on that separate connector ? I don't get it ..... whats the difference in these wires ? Thanx a million.
Posted By: jimmeezgolfvr6
Date Posted: July 01, 2004 at 2:33 AM
that orange wire on the separate connector is the one that's supplying constant +12v power. on the 3 other connectors, none of those wires are constant +12v. the yellow wire on one of those 3 connectors is only switched +12v (when the key is in the accessory position). i can't really explain why.....those cars are just built that way.
good luck!
Posted By: kgerry
Date Posted: July 01, 2004 at 11:51 AM
on the power plug the yellow is 12 v switched, black is ground, grey is illumination and pink if it's there is power antenna.... 12v constant is supplied on the small 2 pin plug i mentioned... dont question why.... that's just the way it is.... hook it to 12 v constant and i'm sure you'll find your problem is solved..... ------------- Kevin Gerry
Certified Electronics Technician
MECP First Class Installer
Owner/Installer
Classic Car Audio
since 1979
Posted By: ed112
Date Posted: July 02, 2004 at 10:46 AM
Okay, I've established by way of multimeter that no power is running through the memory B+ wire. Im thinking of drawing a cable directly to the positive terminal of the battery from the head unit (remember i have no amp).
My question is, what gauge size wire do I use and what fuse amp rating should I employ to fuse this wire ?
Would a 16awg wire with a 1A fuse do the job ?? |
Posted By: kgerry
Date Posted: July 02, 2004 at 12:04 PM
did you check the fuses in the vehicle? does the cig lighter or interior dome light work? they are all on the same circuit......
-------------
Kevin Gerry
Certified Electronics Technician
MECP First Class Installer
Owner/Installer
Classic Car Audio
since 1979
Posted By: mcgyver74
Date Posted: July 02, 2004 at 12:39 PM
I tend to agree with everyone here. Your radio is not getting 12V constant. There is no need to run a wire to the battery. there is a wire back there that is +12 Constant. It is orange. IF the stock wiring is there, then it is part of a 2 pin plug that is back there somwehere. Worst case scenario, you can tie into the Cig lighter GM's used the same color scheme for a long time (Since 1978 I think), the only thing that changed was the plugs, With adapter harnesses becoming so widely available I haven't had to splice a car's wiring harness in a long time so I don't know if the new GM/s are still using the same color scheme but If I recall correctly the basic Color scheme for a GM radio for a post 78 model is B+ Orange Ign Yellow Grnd Black Illum (Grey if i recall correctly) Power Antenna Pink Speaks were Rt Front + Light Green Rt Front - Dark Green Left Front + Tan Left Front - Grey Right Rear + Dark Blue Right Rear - Light Blue Left Rear + Brown Left Rear - Yerllow The wiring in a GM is kinda counter intuitive since the Positive speaker wires in the back are the darker wire and in the front it is the lighter colored wire. Oh and be carefull on a pre 78-79 GM, they used Common ground wiring that could toast a high power unit in less time then it takes me to get ito trouble at a bar :)
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