Newbie dealing with dash bulb sorcery (1 Viewer)

[Olive1]

Hello,
I purchased my '77 40 about a year ago and been lurking on this site for a while, getting ideas and helpful stuff. Thanks to all! I found many great posts....enough to get myself wound around my own axle, so to speak.

While everything worked as normal with the dash board when I started, I planned to remove dashboard, clean it up and replace bulbs with LED per the many helpful posts. As far as I can tell, it is the original dash, looked like it had never been opened up. I'm mid project and was just checking to see if bulbs worked before cleaning and buttoning back up However, now all sorts of issues with different lights coming on at different stages of lights being on, keys on/off, etc per the following pics:
Pic 1 Key off, headlights on (the green light by the MPH is a reflection)
Pic 2 Key on ACC headlights off (again green fuel light is a reflection)
Pic 3 Key on ACC headlights on
Pic 4 just to show a pic of Olive if anyone is interested...
Other points:
The turn signals work as normal, even though one glows when not engaged.
I cleaned the connectors contacts gently.
I tried reversing the polarization on each of the non-lighting LED bulbs.
Using the 194 WWH P5 bulbs I had to mildly deform (but did not remove) the shields to make fit.

I am hoping it's just something dumb by me,

Any help is appreciated.

 

[SteveH]

Huge caution: if you accidentally short the ammeter lug on the dashboard while pulling out the cluster with the battery connected, you will be sad and need a new ammeter. Pull the battery neg. terminal before you remove the instrument cluster and be super careful about powering up a partly-pulled instrument cluster.

Sharp Olive truck - best color ever!

I don't favor removing the shields because it causes bulb reflections in the side windows at night. Most turn signal problems are caused by corrosion or bad grounds at the turn signals themselves, and not by the indicators in the cluster. I know many people use LEDs, but you can experience weird flasher and turn signal problems in older trucks with LEDs. Also, many cheap Chinese LED bulbs seem to fail within a year or two. Just my .02 there.

 

[aging fleet]

Nice looking 40.

I'm not sure what the issue is, but I'd probably start by checking my ground connection. Be careful with your cluster pulled out and battery connected, you've got hot connections behind the cluster that can be shorted on the body.

 

[thebigredrocker]

pic 2 you said headlights are off. Your blue high beam indicator looks to be on. correct?

Not sure what you mean by "green fuel light". I see a green right blinker indicator is on in pic 2

*edit* I now see the reflection you mentioned

 

[ToyotaMatt]

 

[Olive1]

pic 2 you said headlights are off. Your blue high beam indicator looks to be on. correct?

Not sure what you mean by "green fuel light". I see a green right blinker indicator is on in pic 2

*edit* I now see the reflection you mentioned

Yes, that indicator is sometimes off and sometimes on.

What mystifies me is all these bulbs worked as intended before I switched them to LEDs.

 

[Olive1]

Huge caution: if you accidentally short the ammeter lug on the dashboard while pulling out the cluster with the battery connected, you will be sad and need a new ammeter. Pull the battery neg. terminal before you remove the instrument cluster and be super careful about powering up a partly-pulled instrument cluster.

Sharp Olive truck - best color ever!

I don't favor removing the shields because it causes bulb reflections in the side windows at night. Most turn signal problems are caused by corrosion or bad grounds at the turn signals themselves, and not by the indicators in the cluster. I know many people use LEDs, but you can experience weird flasher and turn signal problems in older trucks with LEDs. Also, many cheap Chinese LED bulbs seem to fail within a year or two. Just my .02 there.

Thanks! we really like the color.
I was careful to disconnect the battery. I will check the grounds, but the crazy thing is that it all worked fine before the bulb replacement began....
Thanks for your help.

 

[MOTOV8R]

I had some that didn’t come on as well. For me it was a combination of getting a good connection from the light holders to the housing and getting the polarity right.

 

[Olive1]

As I was going back over everything, saw this.... not sure if I did or was previously there. It can't be good, right?

 

[thebigredrocker]

You know....when the gauge cluster is screwed into the dash it is grounded. While cluster is flopped out try grounding the cluster using a gator clip wire.

I know weird stuff can happen when you have dirty grounds. If your problem continues, wouldn't hurt to scuff everything up. Could pull your Hazard switch apart and clean it.

 

[Olive1]

You know....when the gauge cluster is screwed into the dash it is grounded. While cluster is flopped out try grounding the cluster using a gator clip wire.

I know weird stuff can happen when you have dirty grounds. If your problem continues, wouldn't hurt to scuff everything up. Could pull your Hazard switch apart and clean it.

No I did not know about the gauge cluster grounding, thanks.

 

[thebigredrocker]

might be time for a new gauge cluster

View attachment 1833679 Got a few. $500 for a complete cluster.

 

[Shark56]

I have seen clusters with solder jumper across those burn outs.

Edit to add: I got this pic from Mud many years ago. I can't recall what year it applied too.

 

[brian]

you smoked a ground side circuit on the board.

 

[Olive1]

You know....when the gauge cluster is screwed into the dash it is grounded. While cluster is flopped out try grounding the cluster using a gator clip wire.

I know weird stuff can happen when you have dirty grounds. If your problem continues, wouldn't hurt to scuff everything up. Could pull your Hazard switch apart and clean it.

UPDATE
Ok this was it. I was simply leaning the cluster back on the dash each time to test the lights before reinstalling. Clearly it wasn't properly grounded without using the two screws....So went over all the connections again, checked polarity on the LED bulbs all is in good working order. As I was hoping, it was just operator error (lack of knowledge).

Thanks to all for the coaching and help.