1967 GT500 In-board Light Issue

[bullitt1939]

The inboard are not coming on with the high beams. The relay is not clicking. Where can I get another relay to start there?

[Bob Gaines]

The inboard are not coming on with the high beams. The relay is not clicking. Where can I get another relay to start there?

There is no relay to click because the factory did not put one in the system. Some past owners modify the system with relays and such. There is a circuit breaker made into the headlight switch. It makes a click when it overheats and breaks the circuit. When it cools down it makes the circuit and the lights comes back on.

[JD]

As Bob stated the original Mustang switches were not designed for that amount of "pull", most replacement headlight switches you can get today are rated for 4 High-beam lights like used on Cougars. 

[bullitt1939]

This is what is attached to the fog lights. So trying to find out where the issue is.

[Bob Gaines]

This is what is attached to the fog lights. So trying to find out where the issue is.

There are no fog lights from the factory on 67 Shelby . You have low beam and high beam from the factory. What you picture is something a past owner has added.

[bullitt1939]

Anyone have a wiring diagram? Should I ditch the relay? It was on here from something previous so wondering if it was overheating or something.

[Poor Ron]

That is a much more recent Mopar relay

[JD]

There are no fog lights from the factory on 67 Shelby . You have low beam and high beam from the factory. What you picture is something a past owner has added.

On a '67 Shelby the fender lights are low & high beams and the grille lights, inboard or outboard, are High-beams (not Fog or Driving lights).

Yes, delete the relay, make sure the wires are all routed/connected correctly (look at the wiring diagram in the Branda book "1967 Shelby GT350/GT500 Master Assembly Manual" page 19) and the headlight switch is one that is equipped to handle the load.


Added, image of Branda Book...

[bullitt1939]

Thanks for all the help. This forum is amazing. I changed the relay to get everything working for the upcoming weekend. I will order the manual. Should I go ahead and change the headlight switch as well? I am not sure how old the one in the car currently is.

[Bob Gaines]

Thanks for all the help. This forum is amazing. I changed the relay to get everything working for the upcoming weekend. I will order the manual. Should I go ahead and change the headlight switch as well? I am not sure how old the one in the car currently is.

I think changing out the headlight switch for the modern equivalent would be prudent IMO. Given the installation of the relay by a PO they must have had a issue with the lights and consequently the headlight switch that is currently in it. The higher capacity replacements may lessen the chance of a issue reoccurring. It will look the same from the passenger compartment side so don't be worried.

[shelbydoug]

Does this information ONLY apply to inboard lights? Is there a difference in the original light switch on inboards v. outboards?

[JD]

Does this information ONLY apply to inboard lights? Is there a difference in the original light switch on inboards v. outboards?

Not to my knowledge, it was like this on all '67's from San Jose.

[roddster]

I think there was at one time aircraft landing bulbs on that car, or possibly Cibie for light bulbs.

[Bob Gaines]

Does this information ONLY apply to inboard lights? Is there a difference in the original light switch on inboards v. outboards?

Not to my knowledge, it was like this on all '67's from San Jose.

+1 . No difference on inboard or outboard and no difference from regular Mustang. But history has showed that there should have been.

[Royce Peterson]

If all four bulbs are incandescent the OEM style switch can handle the load, OEM or replacement if in good shape.

If someone installed any halogen bulbs then the system will draw too much current when all four are lit up and eventually the circuit breaker in the headlamp switch will blow, yielding unexpected darkness.