Mine is still sitting up under the dash on my 74 ... it ain't yellow though ... it is either gray or metal encased. Was this box up under your dash? I really don't see the point of removing it or am I missing something?
Yea, its always in the way. Anytime I do anything to my dash, I have to unscrew it and move it out of my way. It also seems to have control over weather the car runs or not, and I don't personally trust 31 year old resistors, chips and capacitors to make my car run.
I just got mine out and the yellow box is the same, but the circuit board looks completely diffrent then the one pictured on the first page. Mine also has the date stamped on it, 2/27/74.
my car is tarped and I can't get to it today but when I get a chance I'll check the wire colors and see if I can track it down on the wireing diagram. I just can't imagine that that is for the seatbelt circuit. I'll ask my father tomorrow and see if he remembers them. ( Ford mechanic for many years but owned a body shot since late 60's)
Ok, we all know that if you short the wires under the seat together that the "seat belts" light and buzzer comes on when you turn the key. If you leave the wires under the seat shorted together and disconnect the yellow box, the car starts and runs as normal. :bananaman I am in the process of figgureing out which 2 wires in that plug under the dash to connect together. I'm using a piece of wire with a 5 amp BUSS fuse in line to do it. I've blown a 5 fuses and am out so I gotta run up to wally world and buy another set of them. I gotta be close. There is one black wire and one green wire with white tracer going into the plugs under the seat. I connected those same color wires together on the plug under the dash and my dome light fuse blew when I turned the key on. I'll let you guys know as soon as I figgure it out. That greenish clear box in the pic on the first page is a relay. If I short it with a jumper wire, it clicks and the buzzer under the dash comes on. Something on that board has some decent voltage going to it when the key is on, I got zapped. If any of you guys have a way of posting one of those wireing diagrams, it would help me enormously.
All I can add is mines green. Also you could take it out of the car and use it as an anti theft device.
Love it. Well, mine is going bad which is why I want to get rid of it. I took it to Autozone a couple of days ago and ran the part numbers...nada. The guys had no clue to what it was. I agree, there's to much solid state stuff in there to just be a interlock. That may be one purpose but there could be others. If someone can scan the wiring diagram I can look it over. I work on manufacturing equipment in my other life. E-mail it to coyote10@comcast.net
For the record, mine is gray. When I got my car in '84, the carpet was faded badly. We removed the seats to dye it and I found the wires unplugged. I plugged them in and as Craig said, car won't start with any weight on a seat. When I restored mine, I left that 'gray' box out and used the directions found in Chiltons-no I don't have a scan-to bypass it up front by the washer box to eliminate the function and the button bypass box that mounts in the same area. Mine runs fine. I think that you can bypass it under the hood and leave this mess of wires alone under the dash. Perhaps someone else has a different point of view. Seth
My appologies Craig. You are absolutely correct. The box not only controls the seatbelt interlock system but the dome light and seat belt buzzer (neither of which currently work in my car). I've found some useful links based on a google search of D4AB-14A554. Here's a guy who sells reverse engineering schematics...could be useful if you want to keep dome light functionality: http://www.bomarc.org/AUTO.php (search for D4AB) Here's the whole sordid story, pretty much what Craig has already told us: http://www.thecarconnection.com/Enthusiasts/Classics_Corner/Yoostabees/Yoostabees_How_Seatbelts_Evolved.S216.A8741.html Here are the only discussions I could find at other car sites: VW Buses: http://shoptalkforums.com/viewtopic.php?t=84262&start=0&postdays=0&postorder=asc&highlight=&sid=02075403a7f48e25d43ab11129b02f58 Matador Coupes: http://www.matadorcoupe.com/1974.htm Unknown: http://archives.freaks.net/checker-l/2000/1991.html I'm surprised the subject isn't all over the internet since ALL makes had the interlock in 1974. I would think the Mustang folks have this covered. I think I may just take the wiring out of my 1970 parts car and replace the 1974's guts 'cuz if this thing ever goes out I'm in trouble. Mike
Seth ... I just reread the Chilton's bypass method and what you are saying makes sense. It looks like that by splicing the wires together it is making the override switch always on override. The purpose of the override switch is to either allow the car to be started using a remote starter while working under the hood or to allow the car to start in the event of an interlock failure. I am guessing that removing the box completely would be the same as an interlock failure ....
What year Chilton's are you refering to? I have a 1974 and a 1977. I can't get to the 77 right now but would it be in there? Thanks for the info Seth...you posted while I was writing mine.
It is not in the 74 Chiltons ... although the 74 does have the interlock wiring diagram. The 77 Chiltons has the bypass instructions on page 51 ,,' It says to pull the connector out of the switch under the hood ... cut the RED/LT BLUE STRIPE WIRE and cut the WHITE/PINK DOT wire and then splice them together. Then plug the harness back into the button to prevent rattling. DO NOT CUT THE RED/YELLOW HASH WIRE .... if you accidently splice this wire into the other wire the starter will crank at KEY ON instead of START position ... ...
