I can't get all the lights to work on the gas gauge and the speedo. When I say lights I mean the night time lights. Eash gauge has more than one light that comes on when the head lights are on. I can only get one light bulb to work on both the gas and speedo gauges. I switch the bulbs and still nothing. I checked the wires and they don't seem to be loose.

All the other lights work fine.

Any ideas?

 

I just took my speedo apart.

On the PCB where the harness plugs in there are 4 pins. Two of my pins were loose because the pins go thru the PCB and are crimped over. Where they enter the PCB they make contact w the traces. IDK if my lights didnt work or were very dim either way they stunk. I considered trying to solder the pins down but typically the heat required to heat the pins and PCB will lift the PCB trace.

In the end I found a column shift speedo for cheap and swapped the PCB and now I can see how fast Im going at night I gotta slow down

i think I have a pic showing the issue I will try to find it

 

pics show the four pins (two were loose),

a close up of the loose pins (factory defect ?)

the backside of the PCB

 

Not a factory defect, but definitely a weak spot. I believe that you can very successfully solder the bottom of the pins to the traces. I had the same problem with my 66, and had to re-solder them all. Those traces are huge, and it would take a lot to lift them (I dabble in electronics also), in addition they are anchored from the back of the PCB. You will want to use a temp controlled solder station if possible, as you don't want to overheat the joint. Excessive heat is generally what lifts traces. I would be happy to solder it for you if you would like, just mail it to me.
Randy

 

Make sure the metal brackets under the mounting ears of the gauges have a wire going to chassis ground.
I assume your other dash lights work?

 

Hi Randy

thanks for the offer. I have another PCB that was intact that I used. I mentioned the lifting traces for those who may not have much experience w soldering. I agree the traces are huge (especially by todays standards) but the pins need to reach temp too

re factory defect; look closely at the back side images one pin is missing most or all of the tabs the mount it another appears to just be loose

 

You can also snug the pins by GENTLY tapping those crimps tighter. Also, if you put some epoxy such as JB Weld over the area, it will be much stronger. You can even cut a teensy bit of thin wire to go down into that pin, and bend the end over and glue that to the board as well.

You can test the illumination on the bench, before reinstalling. Might as well put all new PROPER NUMBER bulbs in, right?

When done, be sure to apply some SILICONE GREASE to the pins so that they don't become one with the connector.

 

Just did this with ALL the crimped pins coming loose (1967 board). Clean the traces and the bottom of the pins with a soft wire brush and some light abrasive. You want clean and shiny copper trace areas and pins. Use a 35-40 watt soldering pencil and basic electronics solder. Hold the tip angular touching both the pin and trace. Wait a few seconds and feed solder into the connection forming a buildup from the trace upward on to the pin bottom. When you pull away, it should cool with the solder flow appearing shiny. If it's grey or dull, it's a cold solder joint and you need to apply more heat and new solder as necessary.

This works great the pins become rigid. I had two completely broken off. I pushed a small brad up from the bottom side of the board and placed the loose pin over it as a guide. I flowed solder around the entire base of the pin. They stuck firmly and remain rigid when handled.

 

If the pins are hollow, a member here had good luck threading tiny screws (#2) into them from the back PCB side.