I got my car back from the body shop and now it won't start. I think they may have knocked the brown wire loose from the right side relay that sits under the seat. It looks like there are 3 or 4 holes it could go into. Any help would be greatly appreciated.

P.s. I know it's pretty crusty. Getting them cleaned up down the line

None of those "connections" looks like it has recently lost a wire.

The brown wire is not in the picture

Brown is normally a ground. Also you didn't mention what year vehicle. I've only owned early cars, no relay box under seat that I recall... What does the relay box do? Taking a WAG it is an aftermarket alarm - Check to see if you have
+12 volts and Ground in the relay box. If no ground, that would be a clue....
Good luck.

From ´74 model year (USA) on the car can only be started with the seat belts put on in the proper sequence.
That is controlled by the "logic relay box" under the seat and a contact in the seat cushions, together with contacts in the seat belt lock.

Checked with my factory manual, "unfortunately" only in german.

"Engine can only be started with the seat belts on..."

thats exactly what it is.
the dreaded seat belt interlock system.

some remnant of it must still be in the car but wired "around".
disconnecting the earth has brought it back into play?
its a sh$t of a thing.
i got a migraine out of it 30 years ago.
it would be doubtful yours was still fully functional before it went into the body shop.
99.9% of owners immediately had it dealt with when new it was so horrible.
why i say its probably wired around. but the loose earth might be necessary to the wire around solution.

mine had been wired around, but the relay was still in the circuit. its just that you did not need to do seat belts up etc to start. but the relay was screwing up and cutting out when it got warmed up internally. i would get into situations where the car would not start after being warm. it would start cold. i imagine your car might have the similar "solution". so the earth being knocked out has brought it into play.

a wiring diagram for the 74 model year will sort it out.
the relay is still in my car. i could take the seat out and photograph it but its a lot of trouble and its been wired around anyway to cut it out of the circuit and incorporate a hidden kill switch.

Thank you for the suggestions but a seatbelt bypass was done by the po. It is a '74 and it's been started it many times without the seatbelts in.

brown is ALWAYS ground on a 914

First, get a wire brush or tooth brush and clean that thing off so you can see what's what! Then pull, clean and reconnect the existing wires in sequence just to be sure its not a poor connection.

Then look in those holes. Some may not have a spade receptical so that may eliminate your choices.

Next, check for 12v on those wires with meter or test lamp. If it's a ground you're missing at least one of them should be hot.

Then test for 12v in the holes and if any are hot - don't connect the brown wire there!

That may only leave one slot that could need the ground, but if it were me, I'd remove the relay and bench test with a 12v source (applied where you found the hot wire when in the car) to make sure grounding that lug is what you need for the relay to fire. Take a photo of the wiring before removing.


just my 2 cents

Ron

Forget that connector.
Check for gas and spark.

When you say it currently "won't start" what exactly is it doing? When you turn the key to start:
Does the starter operate at all?
Does the starter click but not turn?
Does the starter turn the engine but the engine shows no sign of combustion?
Does the engine sputter like it's trying to start but won't actually reach idle speeds, and immediately dies?

If the problem you're experiencing is a result of the wiring under the seat, then that would result in the starter doing absolutely nothing at all.

not all bypasses bypassed the relay. thats what i discovered 30 years ago.
i could start mine without seatbelts on, but that relay was still in play.
its thirty years ago so its hard for me to remember.
the bypass had been done by the previous owner (first owner of the car) and i remember him telling me he got the dealer to do it. i understand some dealers back in the day would do this, on the side, ve know narthing. you got to remember that back in 74 that thing gave everyone who bought a 914 (and other cars) the total shits. if you put a package on the passenger seat you couldn't start the car. of if your dog sat there.
people just flipped on it and got the things unwired left right and centre. i think the standard dealer fix left that relay in play. but disconnected it from seat belt circuit or pad sensor somehow.

my car would start from cold. no seat belt had to be done up. but after being driven for a while, say 1/2 an hour, if you stopped it would not restart. just dead. it was the relay acting up.

but its hard for me to remember now just how that was so that the relay was still in play.
if that relay in yours was still in play and earthed, maybe its the issue, as the plug is now out of it. not sure, but just thinking.