SAAC Forum

The Cars => 1967 Shelby GT350/500 => Topic started by: rmarble57 on January 30, 2021, 03:16:05 PM

Title: Seat Belt Warning Light
Post by: rmarble57 on January 30, 2021, 03:16:05 PM
My Seat Belt light has just taken on a mind of its' own.  In the past it used to come on for a few seconds after turning the ignition on and then would go out for the duration.
Now, it comes on and just stays on.
Anyone know what triggers it to turn off?

Thanks in advance.
Title: Re: Seat Belt Warning Light
Post by: rmarble57 on January 30, 2021, 03:32:05 PM
Since I got my "Google Certified Mechanic" patch for my coveralls, I decided just to have a look around.
Looks like there is a resistor of some kind up under the dash and I'm assuming that can fail and stay "open" leaving the light on.
Best option for a new Resistor setup?
Title: Re: Seat Belt Warning Light
Post by: Bob Gaines on January 30, 2021, 03:59:38 PM
Quote from: rmarble57 on January 30, 2021, 03:32:05 PM
Since I got my "Google Certified Mechanic" patch for my coveralls, I decided just to have a look around.
Looks like there is a resistor of some kind up under the dash and I'm assuming that can fail and stay "open" leaving the light on.
Best option for a new Resistor setup?
If you can't find from a junk car I see them on Ebay frequently. Still too relatively available to warrant rigging up a non original substitute IMO.
Title: Re: Seat Belt Warning Light
Post by: Krelboyne on January 30, 2021, 04:14:59 PM
Seat belt reminder relay, looks like this:
Title: Re: Seat Belt Warning Light
Post by: rmarble57 on January 30, 2021, 04:17:37 PM
Thanks for that.  I disassembled my unit and it is actually a thermal switch.  The body of the unit grounds to the chassis and has a set of points inside.  The voltage from the key switch goes into the switch and has a VERY fine insulated wire that wraps around one side of the points.  Once it heats up from voltage, it distorts that one arm and pulls the points open thus interrupting the ground.

You can see in the picture of mine where the rearmost portion of the windings are yellowed and burnt.  Likely where it doesn't make continuity to the bar and thus, won't heat up.

Guess I could post this on "what did I do to my '67 today", but instead, I'll go on the hunt for a good used one.
Thanks
Randy
Title: Re: Seat Belt Warning Light
Post by: Bob Gaines on January 30, 2021, 06:32:30 PM
He probably doesn't want to toot his own horn but West Coast Cougar would be a likely source to check. Helpful bunch IMO.
Title: Re: Seat Belt Warning Light
Post by: GT350AUS on January 30, 2021, 06:35:34 PM
Is it the same setup on a 73 Mach1?

Mine does the same but it also comes back on when turning right and off sometimes when urning right, also if i take it out of drive and it it back in then it goes off ad n again
Title: Re: Seat Belt Warning Light
Post by: rmarble57 on January 30, 2021, 06:36:43 PM
That is more likely that the unit itself isn't getting a good ground.  Scratch off the paint underneath where the switch bolts to the body.
Title: Re: Seat Belt Warning Light
Post by: GT350AUS on January 30, 2021, 07:36:52 PM
Ok great advice..now where is the located on a 73 as I don't have schematics for it.

Thanks in advance

Ross
Title: Re: Seat Belt Warning Light
Post by: rmarble57 on January 30, 2021, 07:53:18 PM
Follow the wire from in back of the seat belt light.  On a '67 it is down under the dash.  If yours is built in you may have to remove the instrument cluster and it may be more difficult if it is more of the circuit board wiring variety. 
Sometimes older is easier..
Title: Re: Seat Belt Warning Light
Post by: Krelboyne on January 30, 2021, 10:09:31 PM
Quote from: GT350AUS on January 30, 2021, 06:35:34 PM
Is it the same setup on a 73 Mach1?

Mine does the same but it also comes back on when turning right and off sometimes when urning right, also if i take it out of drive and it it back in then it goes off ad n again

Yes, there is also a D2.... numbered relay.
Title: Re: Seat Belt Warning Light
Post by: csheff on January 31, 2021, 12:55:40 PM
Seatbelt light only on some 67 Shelby's?
Title: Re: Seat Belt Warning Light
Post by: JD on January 31, 2021, 01:01:52 PM
Quote from: csheff on January 31, 2021, 12:55:40 PM
Seatbelt light only on some 67 Shelby's?

Yes, from the '67 Running Changes article in the Fall of 2013 The Shelby American...
Title: Re: Seat Belt Warning Light
Post by: roddster on February 03, 2021, 12:18:16 PM
  The seat belt light relay:  I don't know.  My relay is very similar to those starter relays from old Flourescent fixtures.  Round and short. 
Title: Re: Seat Belt Warning Light
Post by: Bob Gaines on February 03, 2021, 12:55:14 PM
Quote from: roddster on February 03, 2021, 12:18:16 PM
  The seat belt light relay:  I don't know.  My relay is very similar to those starter relays from old Flourescent fixtures.  Round and short.
I have seen that type also and maybe a different vendor. 0001 had the long type when I restored it . The timer is typically mounted in a hard to see spot up high under the dash so observations get missed often.
Title: Re: Seat Belt Warning Light
Post by: JD on February 03, 2021, 01:10:00 PM
...another (earlier/1966) version of the long relay with the contact tabs at 90 degree to each other...