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Wiring advice

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boxfullofyertoys

boxfullofyertoys

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Hey everyone -

So I finally wrapped up my floor prep and got the Miata seats installed. I'm really thrilled with them...much better than the stock ones :smile: Anyway, I decided to get moving with the stereo installation in order to take advantage of the speakers in the seats. Upon pulling everything in the center console out and going over it, I discovered that the power wire connected to the old head unit was dead, and also wasn't on my wiring diagram. I was able to trace it back, and it looks like it goes to an accessory port on the ignition. I did a quick test to determine if the wire is good (it is), however I can't check where it's attached to the ignition to see if it's properly connected.

So with that in mind:

- Is my hunch about the acc port on the ignition switch correct? Does such a thing exist?
- If so, is there any easy way to get the shroud on the steering column off so I can see what's going on? I have a feeling it's not going to be as simple as loosening the screws on the shroud...

Thanks!
 
The shroud removal is as easy as the screws but be careful - it is unobtanium. If you could tell us the wire color, that would help a lot
 
The wire changes colors from its trip from the console to the ignition. Here are the colors, in order from console to ignition..

Red--> (wire nut)--> White w/ green stripe --> (large white plastic coupler with multiple connections right behind steering column)--> White w/ green spiral--> (blue butt connector at the shroud)--> White w/ red stripe--> The Abyss

The butt connector and multiple wire colors were a dead giveaway that the previous owner did some work. I know it is a path because I disconnected it at the large white coupler, and then put 12v onto the exposed wire at the console. I then checked for the voltage using my meter at the pin on the white coupler (I also disco'd the 12v and then checked it again to make sure there wasn't a load). From what I can tell, the rest of the wiring for the ignition is all wrapped together in a loom, so I'm pretty confident that that wire is connected to some sort of acc "port" on the ignition. I believe my wiring diagram has a WR wire coming off the ignition, however I have a hunch that the ignition was rewired, and all bets with the color coding are off. Until I look at it, I won't totally know what I'm dealing with...

As for the shroud around the steering column, I removed the screws and she doesn't want to come off...I feel like I just don't have enough room to maneuver the two halves of the shroud forward and then off. Is there any way to remove the signaling/control arms on the left and right sides of the column?
 
Dave,

I can't say for a 75 but on my '68 there is no such thing as an accessory switch. Turning on the key powers the fuel pump, points can close and burn out etc. Here is my solution to this problem.

There are two sides in the fuse box, one switched when the key is turned on and the other always hot. I took the power wire to the radio and ran it to the center post of a mini SPDT(single Pole Duble Throw Switch) I got from Radio Shack. Switch is mounted on the left underdash mounting bracket but my left knee under the dash and hidden. Power from the switched side of the fusebox connectes to one of the outer terminals on the switch and power from the always on side of the fusebox connects to the other terminal on the switch. Another source for power is the side of the solenoid where the battery connects. A fused wire with a big ring terminal on it can connect there for power source. In normal operating mode the radio goes on and off with the ignition switch. If I'm parked and want to listen to some tunes, I simply flip the switch by my left knee and voila power to the radio without runing fuel pump or risking burning out the points. All of this and you don't need to open the column surround.

BTW there are 4 screws on the column surround. the back two are hidden and easy to miss. Column comes apart easily when all 4 screws are removed.
 
Jim - Thanks for the insight.

I think I'm going to run a wire from the solenoid, and run it into the spare bank I have on my fuse box, that way I can wire the stereo, and move my electric choke off of the existing switched circuit to better distribute current load. Luckily enough, I switched to an electronic ignition and my fuel pump is mechanical. No worries about burning that stuff out!

Any thoughts on what gauge the wiring should be?
 
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