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Strange Electrical Issue(Searched)

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Old Feb 23, 2012 | 01:57 AM
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OR Strange Electrical Issue(Searched)

Alright, first - thank you for reading;

I am having an electrical that I cannot seem to pin down - here is a bit of preliminary information --
1988 GTU, ported, rebuilt, etc turbo conversion (see this thread for more details: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/new-read-921298/)
Car has a turbo-timer installed.
Push button ignition has been installed via the instructions outlined on this post https://www.rx7club.com/showthread.p...h+button+start
Several months later, I did a black interior swap which included a new dash - the original harness was retained.
It should be noted that I had no issues after push-start and turbo timer install and prior to dash swap. In other words, nothing was wrong until the new dash was installed.

Key to ON: Heater does not work, logicon does not illuminate at all.

Key to ON, glove box open: Heater does not work, logicon illuminates (but dimly), cigarette outlet works slightly (cell phone charger light very dim for example)

Key to START and back to ON, glove box open: Heater works, logicon illuminates properly, cigarette outlet works

Key to START and back to ON, glove box closed: Heater does not work, logicon illuminates (but dimly), cigarette outlet works slightly (cell phone charger light very dim for example)

Key to OFF, glove box closed or open: Heater works, logicon illuminates properly, cigarette outlet works -> until timer is done counting down and power is shutoff.

Now, I realize that some of the above information is probably unnecessary for diagnosing my issue, but I wanted to provide whoever looks at this post (Hopefully Hailers, Clokker, etc) as much information as possible.

Yes, I have searched and checked my fan motor and logicon - both are in working order. Please do not send me to the FSM, I have a copy and have spent a lot of time buried beneath my dash testing wires and such. Perhaps its just frustration at this point, but I could really use some assistance. Pictures and/or diagrams are very useful for me as I am a visual learner.




Thank you again for your help!
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Old Feb 23, 2012 | 02:02 PM
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Does the cigarette lighter work w/key to ACC?
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Old Feb 25, 2012 | 10:19 PM
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It works at low voltage - not enough to charge a phone for instance.
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Old Feb 26, 2012 | 08:56 AM
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I thnk you migtht have JC-03, a ground block, disconnected. See the two attachments for the general location of this ground point.

Personally I've never had to find it. Seems it's inside the car and ........well look at the jpg attached and find it.

I think it might be constructed like the JC-02 below the trail coils. A plug with many black wires in it plugged into a outfit with prongs on it and this outfit is bolted to the chassiis and acts as a ground point for several items (the black wires in the plug).
Attached Thumbnails Strange Electrical Issue(Searched)-jayceeohthreetwo.jpg   Strange Electrical Issue(Searched)-jaycohthree.jpg   Strange Electrical Issue(Searched)-jaceeohthreeohtheethree.jpg  
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Old Feb 26, 2012 | 09:39 AM
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Seems your turbo timer is supplying the ground for various other units ........somehow.
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Old Feb 26, 2012 | 09:45 AM
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Or pull your ignition switches plugs apart. Jumper a wire b/t the pure BLACK wire in one plug to the pure BLUE wire in the other plug.

This supplies power to your cigar outlet. Now see if you meter/cell charger shows a brighter light. If not.........then I suggest the ground wire is not going to a good ground point in JC-03.
Attached Thumbnails Strange Electrical Issue(Searched)-jumperwireagain.jpg  
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Old Feb 26, 2012 | 11:37 PM
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Well done, HAILERS2!

From the symptoms described, it sure sounded like the glove box light circuit was back-feeding 12v to other systems mentioned. I was thinking a pinched wire grounding out but could not figure out why it would cause only the logicon and lighter to be weird.

However, JC-03 explains it perfectly. Five wires share the connector and are supposed to be tied to a single chassis ground under the dash. The systems it grounds are the glove box light, the logicon and the lighter. If the ground point to the chassis is missing, the glove box light feeds power through the ground side of the ligher & logicon...but some voltage is dropped across the glove box light. So, only partial voltage to the other systems.

The JC-03 [U]connector/U] is way up under the warning light cluster. However, the chassis ground point is on the driver's side of the structural sheet metal that holds the logicon & audio system. HAILERS's image of the JC-03 connector location just clips off the circled '22' identifying the ground point. But, the line pointing to it is there. I vaguely remember seeing it in there once upon a time when I was repairing the wiper cluster switch.

Good luck.
Rob
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Old Feb 27, 2012 | 12:08 AM
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JC-03 Ground point

I took a close look at a large format wiring diagram (see attached excerpt). It looks like ground points '22' and '23' are bolted to the frame at the same location. GP 23 services the audio system...which makes me think I saw when installing a head unit...not working on the wiper switch.

Find the chassis ground connector for your audio system. If the bolt has only one connector and your audio is working, probably means ground point 22 is in there somewhere but not connected. Hope this helps.
Attached Thumbnails Strange Electrical Issue(Searched)-s4-turbo-ground-circuit-excerpt.jpg  

Last edited by RobbyWally; Feb 27, 2012 at 12:12 AM. Reason: Image not attached.
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Old Feb 27, 2012 | 01:42 AM
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Thank you both very much for your quick help. I have this Wed off and will be using the info provided to track this down. I will update that night. Thanks again!
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Old Mar 11, 2012 | 01:21 AM
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Any news? Just curious.
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