Author Topic: LED Problems  (Read 2668 times)

Offline 73C10_Owner

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LED Problems
« on: July 03, 2018, 08:42:40 PM »
My truck:
1973 C10 Stepside
5.0 V8 307

A few weeks ago, I replaced all exterior lights with  LED's except the headlights (brake lights, back up lights, front side markers, rear side markers, and front turn signals).  I left the interior lights alone and all lights worked perfectly.

A few days ago, I replaced the guage cluster lights with LED's.  I had the following results:

1.  The front side markers did not illuminate at all.

2.  The turn signals did not work.  The dash indicators illuminated solid when the turn signal was on and did not flash.  The exterior lights did the same.

3.  The emergency flashers on the dash illuminated solid and did not flash.  The exterior lights did the same.

Today, I replaced both the signal flasher and the emergency flasher in the fuse panel with LED flashers.  I now have the following results:

HEADLIGHT SWITCH OFF:
1.  The turn signals do not work.  The dash indicators illuminate solid when the turn signal is on and do not flash.  The exterior lights (front side markers, front signal lights, and rear brake lights) do the same for each side when the respective signal is activated.

2.  The emergency flashers work correctly.  The dash indicators illuminate and flash and the exterior lights (front side markers, front signal lights, and brake lights) illuminate and flash.

HEADLIGHT SWITCH IN FIRST POSITION (PARKING LIGHTS):
1.  Front side markers do not illuminate.  Front signal lights and rear side markers illuminate.

2.  Emergency flashers do not work correctly.  Dash indicators both illuminate solid and do not flash.  Front side markers do not illuminate.  Front signal lights illuminate solid and do not flash.  Brake lights illuminate solid and do not flash.

3.  Turn signals do not work.  Each dash indicator illuminates solid and does not flash.  Neither front side marker illuminates.  Front signal lights and brake lights illuminate solid when their respective turn signal side is activated.

HEADLIGHT SWITCH FULLY ON:
1.  Driver side side marker does not illuminate at all.  Passenger side side marker illuminates dimly.  Headlights, front signal lights (yellow), and all rear lights illuminate.

2.  Emergency flashers do not work correctly.  Dash indicators both illuminate solid and do not flash.  Front side markers do not illuminate.  Front signal lights illuminate solid and do not flash.  Brake lights illuminate solid and do not flash.

3.  Turn signals do not work.  Each dash indicator illuminates solid and does not flash.  Neither front side marker illuminates when its respective side is activated.  Front signal lights and brake lights illuminate solid when their respective turn signal side is activated.

Any help would be greatly appreciated!

Thanks in advance.
« Last Edit: July 03, 2018, 10:40:11 PM by 73C10_Owner »

Online Rapid Roy

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Re: LED Problems
« Reply #1 on: July 03, 2018, 10:03:46 PM »
Welcome to the site.
1974 Cheyenne 10 LWB STOCK 350 W HEI /TH350/AC/4 BBL Quadrajet
Mopar by Birth
Chevy by Choice

Offline VileZambonie

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Re: LED Problems
« Reply #2 on: July 04, 2018, 06:53:44 AM »
Make sure you have the polarity correct at each bulb socket. Many LED's are directional, remember an LED is a diode. Also check the connections at your cluster and headlight switch. Make sure the hazard switch is off during your tests.
« Last Edit: July 04, 2018, 07:14:21 AM by VileZambonie »
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Offline 75gmck25

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Re: LED Problems
« Reply #3 on: July 04, 2018, 07:06:49 AM »
You need to check the LEDs for correct polarity.  You may want to just pull them out one by one and see if the problem resolves.

However, with all the problems you are having it sounds more like the dash cluster ground is disconnected.  When that ground is off you will get wierd results when various lights and devices try to find a ground path through other devices.

On my '75 the black dash ground wire is connected to a post on top of the emergency brake mechanism. On later trucks I have been told that they installed a grounding bar up under the dash on the firewall.  You may have accidently knocked the wire loose during your work. 

Another place to check is the large muli-plug that goes into the back of the cluster.  IIRC, the ground wire is on one side of the multi-wire plug, so if you rocked the connector and it partially disconnected from the cluster, you may have lost the ground connection.

Bruce

Offline 73C10_Owner

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Re: LED Problems
« Reply #4 on: July 04, 2018, 09:22:57 AM »
Thanks for the suggestions, but wouldn't it mean that the bulbs are oriented properly when they all illuminate at some point?  In addition, wouldn't that also mean that the ground is correct?

Offline 1967KaiserM715

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Re: LED Problems
« Reply #5 on: July 04, 2018, 05:55:19 PM »
When bulbs search for a ground all funky things can happen. It does sound like a ground issue, so thoroughly inspect and fix all the grounds. That means battery to truck, frame, cab, engine, and any other grounds.



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Offline 73C10_Owner

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Re: LED Problems
« Reply #6 on: July 05, 2018, 03:09:29 PM »
UPDATE:

After reading here and some other things online, I reversed the wires inside the fuse panel going to the flasher.  The turn signals now work, but the starter solenoid cycles at the same rate as the turn signals flash.  But it cycles all the time, not just when the turn signals are on.  In addition, the windshield wipers now do not work when I turn them on.

Any suggestions?

Offline 73C10_Owner

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Re: LED Problems
« Reply #7 on: July 06, 2018, 08:36:41 AM »
UPDATE 2:

I re-installed the wires going in to the rear of the fuse panel back in their original position for the turn signal flasher.  I then rigged a jumper with wires going from each connector of the flasher to the opposite connections in the fuse panel. 

The results:  Everything works (mostly).
1.  The turn signals work whether the headlights are on or off.

2.  The emergency flashers work only if the headlights are off.

3.  The starter solenoid has stopped cycling.

4.  The windshield wipers work (after I plugged the connector back into the wiper motor that I inadvertently disconnected the other day).  LOL!

5.  The front side markers still do not illuminate (except when the turn signals are on).  I'm thinking I may need to install load resistors at the front side markers to fix this.

Online bd

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Re: LED Problems
« Reply #8 on: July 06, 2018, 10:35:18 AM »
The front side markers still do not illuminate (except when the turn signals are on).

What happens if you flip the side marker LEDs in their sockets?
Rich
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