The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post

ray_mcavoy · 07-27-2018, 09:15 PM

How many turn signal indicator lights are in your truck's instrument cluster?

The reason I ask is because the 1962 & 1963 truck instrument clusters usually only had a single indicator that was wired up so it would flash when making a turn in either direction.

The single indicator light was connected with one side of the bulb going to the left front turn signal and the other side to the right front turn signal. This arrangement only works correctly with regular filament bulbs since it relies on the non-active side to provide a ground path (through it's filament) for the dash indicator bulb. With LED's, the single indicator bulb basically provides a path that connects both front turn signals together. And since LED's don't require much current, the non-active side can still draw enough current (through the indicator bulb filament) to allow it to light up.

To see if this is what's causing the issue, you can temporarily unplug the turn signal indicator bulb socket from the cluster and remove the bulb. If that makes the turn signals operate correctly, you'll have to come up with an alternative for the in-dash indicator. Wiring it up like the other years (that used separate left & right indicators) should do the trick so long as you can find a spot in the cluster for the extra indicator.

07-27-2018, 09:15 PM	#2
ray_mcavoy Registered User Join Date: Nov 2009 Location: Sherman, ME Posts: 2,379	Re: 62 led turn signal issue! How many turn signal indicator lights are in your truck's instrument cluster? The reason I ask is because the 1962 & 1963 truck instrument clusters usually only had a single indicator that was wired up so it would flash when making a turn in either direction. The single indicator light was connected with one side of the bulb going to the left front turn signal and the other side to the right front turn signal. This arrangement only works correctly with regular filament bulbs since it relies on the non-active side to provide a ground path (through it's filament) for the dash indicator bulb. With LED's, the single indicator bulb basically provides a path that connects both front turn signals together. And since LED's don't require much current, the non-active side can still draw enough current (through the indicator bulb filament) to allow it to light up. To see if this is what's causing the issue, you can temporarily unplug the turn signal indicator bulb socket from the cluster and remove the bulb. If that makes the turn signals operate correctly, you'll have to come up with an alternative for the in-dash indicator. Wiring it up like the other years (that used separate left & right indicators) should do the trick so long as you can find a spot in the cluster for the extra indicator.