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1970 521 dash lights not working


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Hi guys. I have read several posts and tried the following:


Pulled and cleaned fuse holder

Replaced all fuses

Replaced all dash bulbs


The tail lights come one when you pull the lights on to the first position. The tail lights go out when you pull the light knob all the way out. What else should I be looking for? Could it be a bad control switch for the lights? Oh yeah, the left blinker started working most of the time afte I changed the bulbs.

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After 15 min of digging around on my NL build thread....I've come to the conclusion that I didn't post these pics on ratsun....so here's a link to my PB folder with the pics. Since you have lights in the first position and not the second....it pretty much has to be the switch. These pics will give you an idea what your switch looks like opened up....in case you are brave enough to open it. First, I would disconnect the battery, then cycle the switch about 30 times between the first position and the second to see if that will clean the contacts. On the NL switch, the spring wasn't pushing hard enough...I can't remember, but I might have changed out the springs with ones from a HF box of springs. I did find the folder location on my computer, which has more pics of how it was done, but try the cycling first :)

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If the cycling does not fix it you can remove and carefully pry the tabs back and take it apart and clean it inside. Done this a couple of times with a 620 switch. To get the knob off, unplug, pull the knob full out, grip the exposed shaft with needle nose pliers down close to the dash, push in on the knob to compress the spring inside it and twist to release.

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Here is a picture of the back of the 521 combo meter, and the function of the pins on it.


in the picture you can see a wire soldered to copper trace on the board that connects to the pin at 1:00, the pin supplies power to the dash lights. The jumper was put on because the trace on the printed circuit board was damaged.


This picture shows one of the dash light positions on the meter.


You can see the contact for the bulb holder on one side to the hole is clean, and the other side is not. You will have to clean both sides to get the dash lights to work.


Most likely, the contacts between the lamp holder, and the printed circuit need cleaning. They are made of different metals. Anytime you have different metals in contact with each other, and you have some moisture, you create a battery, and one metal get corroded.

Sometime in the last 40 or so years your 521 had been in existence, there is a pretty good chance moisture in the cab put some condensation on the contacts on the meter, and lamp holders.

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Thanks again the dash lights are now working. The circut board in the dash had started to come apart and the copper had broken on the dash light circut. I was able to glue the pieces back to the board and solder the break. I have a picture I will try and post.

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