Wiring. What is this and what does it do????

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71 'stang

Well-known member
Joined
Jul 31, 2010
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Location
Nassau County, Ny
My Car
A 1971 Mustang Coupe was my first car,
Now rebuilding a '72 Qcode Mach 1.
351/4speed
Having a little issue with a circuit breaker. Id like to know where this wiring goes. The car is a 72 mach1. The circuit breaker attaches to the starter solenoid and the wire is a heavier gauge black with yellow dots along it. It runs along the shock tower brace and through the firewall where it then ends up in the drivers side kick panel and into a yellow connector. Hope some pics will help show what i mean. Anyone know what this powers?

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My what??? Could it of been for the factory a/c?

 
No this is not for the factory A/C. If you look under each of your front seats you will see two connectors hanging down. One of them is for the seat occupancy sensor (for the seat belt buzzers) and then another connector that is for your "seat back release solenoids"

There is a solenoid (A simple linear electric motor) that helps hold the seat back in place while the car is in motion and the doors closed, so that the person sitting in the back seat can't release the seat of the person in front of them and fold them over. It's a security thing.

The solenoid activates when the car door is opened, releasing a pin that allows the lever to move and the seat be tipped forward. This is why those wires are not on a switched 12V source and are straight connected to the battery. It also means that if you leave your doors open overnight you can kill your battery.

The only other thing that gets connected in a similar fashion is if you have a rear defroster, or a convertible, for the motor that helps the top come down.

 
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And i thought you were just pullin my chain! Ive never heard of that, pretty cool! The car does have a factory rear window defroster aswell, all the controls must be missing for it however. Thank you for the information, always good learning new things like that.

 
If you feel under the seat on the outside edge of the car you should be able to feel the solenoid. It's about 4 inches long and about the diameter of a half dollar coin (little smaller)

I have one out sitting on the roof of my car right now that I can take a picture of if you're interested.

Sent from my iPhone using Tapatalk

 
No need to take a pic, but i do appreciate it. If i disconnect the wiring from the solenoid, will the seats still unlatch? Or worse, will they unlatch say, while driving and no one is in the passenger seat, will it fall forward on a quick stop?

 
I'm a little fuzzy on the exact details of this part, but to the best of my understanding this is how they work:

In the unenergized state, they prevent the seat latch from opening, so if you were to unplug one you wouldn't be able to flip that seat forward at all, you'd have to unplug and REMOVE it from the car (Or at least disconnect the mechanical linkage)

My drivers side seat doesn't have a solenoid installed, and the seat still latches quite tightly. The solenoid doesn't handle the actual latching of the seat, only restricts the ability to unlatch it.

Is there a reason you want to remove them?

To address your question at the highest level. If you were to physically remove both solenoids from the car, neither seat should be able to fall forward on their own unless something else is broken. But I don't think just disconnecting them electrically is enough.

Sent from my iPhone using Tapatalk

 
Realistically, id like to clean up the wiring, the car is more of a 'hot rod', previous owners had pulled out the heat, ac, controls for rear defroster aswell as the heat and ac controls, and hacked the wiring. The circuit breaker is actually also rigged to the electric fan and fuel pumps and is popping because of an overload. Id like to rewire and clean up the engine bay, aswell as 'delete' (store on the side) wiring that doesnt have much current necessary use. (The car currently has aftermarket seats in it)


Just wanted to know about the seat solenoid wiring for when i reinstall the factory buckets

 
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Electric pumps and fans are definitely aftermarket. You may have one of these connectors grounding out to the frame if they didn't wrap up the connectors properly under the seats. If so, I would suggest that you disconnect your battery, and with an Ohm meter start tracing the wires and make sure you don't have a ground somewhere you shouldn't that's taking that breaker with it.

You could honestly disconnect it at the starter solenoid there and not loose anything else.

Sent from my iPhone using Tapatalk

 
Alright cool, i will definitely go over the wiring on this circuit and find out if who ever disconnected the seat solenoids did so properly. Thank you, i appreciate the help and information!

 
No this is not for the factory A/C. If you look under each of your front seats you will see two connectors hanging down. One of them is for the seat occupancy sensor (for the seat belt buzzers) and then another connector that is for your "seat back release solenoids"

There is a solenoid (A simple linear electric motor) that helps hold the seat back in place while the car is in motion and the doors closed, so that the person sitting in the back seat can't release the seat of the person in front of them and fold them over. It's a security thing.

The solenoid activates when the car door is opened, releasing a pin that allows the lever to move and the seat be tipped forward. This is why those wires are not on a switched 12V source and are straight connected to the battery. It also means that if you leave your doors open overnight you can kill your battery.

The only other thing that gets connected in a similar fashion is if you have a rear defroster, or a convertible, for the motor that helps the top come down.
MechEng,

Just a clarification here. I agree that the CB is for the seat solenoids but wasn't it part of the convenience group that allows the person getting into the back seat to move the front seat back forward without having to manually release it? There is a lever to manually do this if the solenoid fails. Maybe I am totally missing what the discussion is here.

-jbojo

Oh yeah, in my car the solenoid is in the seat back.

 
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You know what Jbojo. You're absolutely right.

I was working off what I had been told they do, since my drivers side is missing it I had no idea I had been misinformed.

From the sounds of it I was even told a bad mounting location.

I double checked and you're right, the convenience group adds them as "automatic seat back releases"

71 'stang I apologize for giving you bad information as to their function! But this is good news for you as it means unplugging them is enough to accomplish your desires.

Again my apologies and thanks to jbojo's sharp eye

Sent from my iPhone using Tapatalk

 
Not a problem, I actually haven't had an opportunity to get to work on the car since asking about what this part is. Thank you Jbojo for your input, and MechEng for the responses

 
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