Testing Dash Lights---Dash Removed

[madkaw]

I have the dash sitting on the bench 9/71 and I want to test all my dash lights while it's sitting in front of me. What wires can I jumper with a 12v source to get that done?

[Captain Obvious]

My documentation for the early years is sketchy, but I believe it goes like this:

 

Green/White is the +12 side.

Black is the ground side.

 

I'm assuming there's only one G/W in the dash harness, and you should be able to pick it up at the headlight (combination) switch connector.

 

You should use a current limited power supply if you've got one or put a couple amp fuse (like 2A) in series with your power source just in case. Maybe turn the dimmer control full dim before you make any connections and then turn it up after you have power on the circuit?

 

And anecdotally... They changed the wiring scheme somewhere along the way. The earlier cars (maybe through 73?) had the dimmer on the high side and the later cars (74 on?) had the dimmer on the low side. But I don't think it matters for what you're trying to do.

[madkaw]

Thank you, I will give it a shot in the morning.

[madkaw]

You nailed it Captain- thanks!!!

All bulbs checked

[Captain Obvious]

Excellent. It's always a little tentative to provide that level of detail when I don't have the official documentation.

 

Glad that worked out and glad you got your test done.

[madkaw]

Changing bulbs with the dash out is too easy:)

[oranngetang]

What bulb number did you go with? I ordered some Chinese led bulbs in various form factors a month ago and they havnt showed up. What I could find local for incandescent bulbs seemed to be too tall for the green plastic lens or too low a wattage.

All new bulbs throughout and I still can't see any of my gauges at night except the 'newer' amp/fuel gauge that has the back light bulb location on the side, rather than the centre.

Considering drilling another whole and splicing in a 2nd bulb per gauge, possibly knocking out the green domes.

[Namerow]

Two options (that I know of):

 

1. Eiko A-72-BP.  These have the same 'BA9S' base and 'G3-1/2' globe as the original bulbs, but are rated at 4W output (compared to 3.4W for the original Japanese 'Life' bulbs), so ~ 15% higher output rating.  They're available in a 10-pack (you'll need 12 for a 240Z, if you include the glovebox light). 

 

2. MSA are now offering a replacement kit, consisting of 15 bulbs.  These are said to be rated at '3.5W+' output power, which MSA say equates to 24 lumens of lighting output (the OE bulbs were rated at 20 lumens).  $29.95. 

 

Be careful of alternatives that offer higher output ratings.  They'll fit the socket but often have a base that's longer than the OE bulbs so they project too far into the gauge (i.e. bump up against the green plastic shade).  Also, the globe (glass part) may be a bigger diameter.

[oranngetang]

These are the bulbs I ordered. Of the two, the full yellow/domed style was a hair smaller in diameter than the four diode bulbs, but both fit and left a tonne of room between the socket and green plastic domes. The domed style is also slightly brighter than the other, or so it appeared. Dimmer switch is full bright in any position due to the insignificant current draw.

 

The color appears as a white/blue tone, even through the lens ~8000K ish. Much brighter than stock bulbs, though the speedo still seems like it could use more lumens. This is the auction I purchased them from on eBay.

 

10 of them for $3.64 USD and free shipping.

 

[madkaw]

I used what MSA was advertising years ago. They are too long at the contact point and sometimes don't ground correctly. I had to file down the solder on the contact to get them to work. And oddly enough the speedo ones never did want to ground right so I put the OE ones in