There is a large factory hole on the drivers side of the tunnel (near the rear firewall) - I assume that’s where the electrical plugs for the seat belt warning lights exit the tunnel/loom .. is that correct? I could also see them possibly exiting with the 3 interior light wires (on top of the tunnel). Also, Is it normally routed above the the solid brake line as in the picture? TIA.

Anyone got any info? I'm kinda in the dark as to how the whole seat wiring thing goes on a '72 in general.. So, besides needing to know the factory route out of the tunnel for the elec. plug loom, I assume that one of these electrical plugs is for the seat cushion and one is for the belt receptical and that's only for the driver's side - do I have that right?

So, is it weight on the seat that activates the 'fasten seat belt' lamp when key is on, and then clicking into the belt receptical de-activates it?

Any info appreciated!

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I think most have disabled them. Be patient, someone will chime in with an answer. I am having the same problem getting things done at work this week, most are gone right now.

Here’s a better pic showing what I’m trying to work thru. The curly Q wire from the driver’s seat is the only male plug that fits to the belt receptacle.. but is that right, and there’s also a plug @ the passengers side belt receptacle but of course that seat cushion has no curly Q wire/sensor. So..(??)

Then there is the round elec. plug from the tunnel - I don’t have anything that fits it

perhaps, the belt receptacles are not appropriate for the '72? Don't I recall seeing at some point "siamese twin" seat belt receptacles who's wires were both connected together with one elec. connector and could not be separated ?

Ok well just to confirm for anyone in the future who may be wondering - the early ‘72 (probably all the early cars) have seat belt receptacles that share a single round shaped electrical plug for the ‘fasten seat belt’ dash light operation. I went looking thru my parts cars and found these, which would have been original to this current project. So obviously the rectangular plug from the tunnel plugs to the driver’s seat.

Now about the routing, I’m still lost on that detail… anyone ?

The 72 passenger seat pad switch connects to the system not the drivers seat pad. Othrwise you have it correct.

Wait, you're saying that an early '72 should have a passenger's seat pad switch? (a curly Q wire coming from the passenger seat?) I'm not seeing that with my PS seat pad. And what do you mean by it "connects to the system" ? What exactly should the round elec. connector connect to?
I'm lost again with your comments - can you explain? Thx

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They don’t route into the hole where you adjust the shifter. You need to be able to get a socket int there whenever you need to adjust… and the wires will be in the way. The wires come out of the top hole and just drape over the top. Not so elegant… but you need access to the adjustment hole on the drivers side.

The 72-73 cars have a seatbelt warning system, I think it’s just the seatbelt light and a buzzer (looks like a round relay but has a bright orange base near the fusepanel) for warnings. The seatbelt light box at the dash is actually a logic board (transistorized) that controls the system. According to the 72 schematic the pass seat pad is switched, as well as both seatbelt receivers, and both doors. Subject to your verification, the light and buzzer activates when the doors are open and when a passenger is seated and not buckled up and when the driver is not buckled up. Close the doors and buckle up and the light and buzzer should turn off.

The small circular connector just connects the seatbelt switches via circuitry to the logic box at the dash, as does the 2-pole box connector for the pass seat pad switch.

The passenger seat pad was intended to be switched, not the drivers side. Likely the seat pad just moved over or was replaced at some point.

Get a 1972 schematic and check all this out if interested.

The 74-76 cars have a completely different seatbelt interlock system.

Perfect, thanks for that!

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Ok, I just assumed the seat pad w/ curly wire was a driver’s side piece - not sure why, but yeah it makes since that it would be the passenger side now that I’ve read your summary of the entire system - very helpful and much appreciated

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So I'm still curious about the large hole in the side of the tunnel (see my first picture), it's factory made but what's it's purpose? Anyone know?

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The hole on the drivers side allows you access to the clamp bolt for shifter rod adjustment. The bolt goes thru the clamp and has a nut on the other side. Both 13MM. You use a socket to reach into the hole for the bolt... and you tighten the nut thru the access panel at the top. I believe tangerine racing makes a one piece clamp that has the bolt fixed.... and you only tighten the nut.

You don't want wires going over the top of that clamp in any case. They will snag on the shifter adjustment when you change gears. Google how to adjust the shifter rod... and you'll find plenty of pictures.

Big thanks for the explanation, I’ve done my fair share of shift rod adjustment.. the last being a side shift set up, but even that was too long ago for me the recall using that hole. This is an early car that I’m adding side shift linkage to. My last early 914 was way back!

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