1970 baywindow dashboard lights mistery

[sioux888]

Hi everybody.

I've been working on the electrical system of my 1970 bus since yesterday.

So far, Ive got headlights working ( not completely though, I need to replace the dimmer relay to get high beams, I opened the old relay and it was completely consumed by rust inside) all the turning lights are working, so is the emergency lights. However, I need to sort out am electrical problem that keeps me banging my head against the wiring diagram.

As I said, the external turning lights are working absolutely fine but, by the exception of the general light that illuminates the cluster instruments, the rest of the dashboard lights are not, I cleaned up all the ground terminals in relation to the circuit according to the wiring diagram and cleaned thoroughly all the contact bits of the light bulb sockets in the cluster, I double checked that the connections in the relay are the same as in the diagram and I got nothing when I activate the lever, I can hear the relay clicking and the external lights work with no issues, but the dashboard lights refuse to come out.

Now, something worth mentioning and that at least to me is pretty weird. I checked with a test light that power is getting to the light bulb sockets and the test light starts blinking on both sides when grounded to an area outside the cluster. Something else is that if I removed the light bulb socket and I ground it to a different area outside the cluster it starts blinking perfectly.
Something else to add is that the emergency switch triggers both lights in the dashboard when the key is off, but it stops when you turn the key ON (last minute update: now the dashboard lights wont work with or without the key ON, but bare in mind the external lights of the bus work absolutely fine)

The only modification I've done to the bus is to add a new blinker relay, the previous one was broken and the previous owner had a 3 prong one instead of the 4 prong shown in the diagram. I bought a 4 prong one and I connected the terminals according to the wiring diagram. (Something that I noticed though is that the new relay has a K1 terminal, instead of the KBL terminal shown on the wiring diagram, which is indeed the one that receives the wire that goes to the
turning lights on the dashboard.

Any thoughts guys???

[airschooled]

Always start with the simplest solution first:

A) The Bentley (and therefore Samba) wiring diagrams for 1970 shows the fusebox upside down, so numbers go 12-1, left to right. The Bentley chart for fuses also lists some mistakes in the 1970 columns.

B) Both the green and blue cluster lights (parking lights and high beams) ground to the cluster assembly, which then needs a good ground to the chassis. Here's the back of an early bay cluster, the ground spades are just right of bottom center; this one has an extra spade adapter.

C) Intermittent light issues often respond well to swapping bulbs and sockets around, with known good examples from nearby. It's just as important to know what the problem ISN'T when you're trying to figure out what it is.

Good luck,
Robbie
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