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Old 10-16-2020, 01:14 AM   #1
BRL
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Angry Dang Dash Lights!

69 dash and all the lights used to work but one day the lower two just quit lighting.

Tried bulb and plug replacement on both with no luck.

Printed circuit looks good to me when viewed from underneath.

Remember someone said to try to clean up the mounting screw near there in an attempt to help ground, but that didn't work either when I tried to loosen/tighten it.

Any further suggestions before I just pull the whole dang cluster out in frustration.

BTW, check out the cool B&M temp. gauge I installed.

Would like to better see that oil gauge at night at least.

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Old 10-16-2020, 07:30 AM   #2
BigBird05
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Re: Dang Dash Lights!

Better check the continuity on the ground and power side of the printed circuit.
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Old 10-16-2020, 09:30 AM   #3
cj847
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Re: Dang Dash Lights!

I pulled my instrument cluster out and found corrosion under most of the dash lights. I took some fine sandpaper and some electrical contact cleaner, cleaned them up, and they all work now.
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Old 10-16-2020, 11:38 AM   #4
REDROCKER652002
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Re: Dang Dash Lights!

My son's 69 had a similar issue, and if i remember correctly, I or he, did not have the bulbs in correctly. But if they were working and just a few stopped, I would guess it would be a bulb issue. Good luck.
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Old 10-16-2020, 11:42 AM   #5
dz1087
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Re: Dang Dash Lights!

None of mine worked and upon pulling the bulbs, about half were blown. Replaced all of them and they all worked fine. As mentioned by Cj847, check for corrosion between the printed circuit board and the cluster.
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Old 10-16-2020, 06:46 PM   #6
BRL
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Re: Dang Dash Lights!

Thanks for the ideas.

Do they all run off of one power feed?

In other words, you don't have one wire feeding part of the lighting and another feeding another part?

Really don't know that much about these trucks, became an enthusiast after buying one years ago and then got hooked.
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Old 10-16-2020, 07:48 PM   #7
dmjlambert
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Re: Dang Dash Lights!

There are no lower bulbs in the cluster. There are 4 bulbs and they all run straight across the back. Perhaps it is the far right bulb that is giving you trouble. When I took my instrument cluster out to work on it, I connected a small 12v battery to it to test all the bulbs, and cleaned up the traces on the printed circuit and the contacts on the bulb holders. You need to be careful testing to keep from shorting aligator clips against the metal case and causing a short.
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Old 10-16-2020, 08:32 PM   #8
BRL
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Re: Dang Dash Lights!

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Originally Posted by dmjlambert View Post
There are no lower bulbs in the cluster. There are 4 bulbs and they all run straight across the back. Perhaps it is the far right bulb that is giving you trouble...
I may not be the best at describing the bulb location but it is the two on the right that light up the two lower gauges that is giving me trouble, they're not lighting up.

I've had the cluster out before, that's how I installed the tach. and trans. gauges.

I've just gotten lazy in my old(er) age, and if I could find a way around removing the entire cluster again I would try that first.

Neighbor has a VW Jetta he wanted me to look at today to see if he had a bad water pump leak.

Couldn't even see the water pump with all that supposedly hi-tech. garbage under the hood!

Watched a You-Tube video on replacing a Jetta water pump, and there was something about removing a motor mount on the opposite side as part of the process.

What JUNK!

I don't feel so bad about pulling my old school truck cluster again now!

ETA: OK let's see if you average backyard mechanics want to get into this.

Me?

NO THANKS!


Last edited by BRL; 10-16-2020 at 09:26 PM.
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Old 10-16-2020, 08:40 PM   #9
dmjlambert
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Re: Dang Dash Lights!

When I reach up under the dash to grab and twist on those bulb holders and check the bulbs and fix problems, I have trouble getting the correct bulb and end up messing with the brake or temp light or some other bulb by accident. It is easy to do. If you have LED bulbs, they are usually sensitive to polarity and only work in one orientation. I use conventional bulbs in mine currently, but I have some LED bulbs for it that I have used previously.
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Old 10-16-2020, 09:37 PM   #10
RustyPile
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Re: Dang Dash Lights!

Quote:
Originally Posted by BRL View Post
Thanks for the ideas.

Do they all run off of one power feed?

In other words, you don't have one wire feeding part of the lighting and another feeding another part?

Really don't know that much about these trucks, became an enthusiast after buying one years ago and then got hooked.
Looking at the plug on the harness end, the grey wire feeds the gauge illumination bulbs.. So to answer your question, there is only one wire feeding them.. BUT, the printed circuit splits off and runs a circuitous route on it's way to each of the bulbs.. This trace could be broken somewhere, or possibly there could be a bad bulb socket or bad connection between the trace and socket where it plugs in.. As I remember, there are 4 bulbs situated so they illuminate all the gauges..

Last edited by RustyPile; 10-16-2020 at 10:56 PM.
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Old 10-16-2020, 09:50 PM   #11
BRL
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Re: Dang Dash Lights!

Hey thanks again you guys, guess I'm going to just bite the bullet and pull the cluster to see what's going on back there.
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Old 10-17-2020, 09:22 AM   #12
REDROCKER652002
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Re: Dang Dash Lights!

At one point, I thought about pulling the circuit board and just wiring all of it. Seeing what a pain it would have been that went right out of my head. My son fooled with it, and found that I had put some of the bulb holders in backwards. At least that is what he told me. LOL.
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Old 10-17-2020, 03:30 PM   #13
RustyPile
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Re: Dang Dash Lights!

Quote:
Originally Posted by REDROCKER652002 View Post
At one point, I thought about pulling the circuit board and just wiring all of it. Seeing what a pain it would have been that went right out of my head. My son fooled with it, and found that I had put some of the bulb holders in backwards. At least that is what he told me. LOL.
hahaha, your son is quite the joker.. Bulbs (not led) will plug into the socket either way.. Sockets also will plug in either way.. Bulbs push straight in, sockets push in then a slight twist seats them..
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