BLKMGK Posted May 5, 2001 Share Posted May 5, 2001 Yeah baby! I've just figured out how to make a bolt-in mount for the Autometer 2 5/8ths gauges in the triple pod of the 240s!!!! I've taken pics of what I did and while I've only converted one gauge so far I've tried it in all three holes. Fabrication was ZERO! No gluing, no added "stuff", just a tiny bit of drilling and some bending with a vice! It's not up on my site yet but I'll do it ASAP today when I'm doone typing here. I'd like to make this a Tech article on this site too as my bandwidth is low and would like for this knowledge to be as widespread as possible. Oh, and this is NOT a radical idea and it wouldn't surprise me at ALL if someone else figured it out first. However I documented it and am darned happy to have found it to be this easy - I was really worried there for awhile. P.S. I might be requesting one tiny part if anyone has a spare. I think since I had two sets of gauges I've got one but so far no luck finding it (sigh). http://216.254.117.47 is my home page, look in the Photo Gallery. I may move it later though to it's own page of How-To's. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted May 5, 2001 Share Posted May 5, 2001 I did it several years ago http://www.zhome.com/ZCMnL/tech/autometer.htm Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted May 6, 2001 Author Share Posted May 6, 2001 Hey, I never thought to simply drill the guts out of the stock gauges - duh! That really does bolt right in then huh? I need to write mine as well as you did, slightly different approaches but it seems like EVERYONE asks how to do it. A Tech Article on it here would be helpful IMO. The resuly looks darned nice that's for sure! BTW Pete, you said the GROUND is what regulated by the dimmer switch, yes? I'm about to start soldering and wanted to be sure. I've considered a few options for the bulbs - I'm thinking cut or splice on of the stock bulb wires and put ALL of the Autometer grounds through that and then using a single hot wire to the fuse box. That sound workable? Just want to be sure it's GROUND that's got the knob on it and I've not been able to find my silly multimeter. Ya' know though - the more I think about that the more crazy it sounds - how can ground be what's dimmed? There's only one wire to each bulb in there which means that it must've been picking up it's ground from the strap I'm modifying - yes? Better dig up the multimeter I guess, no battery in the car makes this a PITA! Update: Okay, I looked closely at the stock bulbholders. It's grounding on the gauge housing as I thought and getting what has to be HOT from the harness. I could swear an earlier post way back said that the rheostat for dimming the bulbs dimmed ground, that can't be IMO. Also, the stock bulbholders very nearly fit the Autometer housings. I almost tried this but considering how dim the stock gauges were (3watt bulbs) I snipped the harness instead and am going to use the Autometer bulbs - colored blue to begin with Not sure if it'll look good or not, I'll let everyone know when I've seen it and might test off the car to see. Now then - how do you yank the Speedo and Tach? That job is fast approaching I'm afraid. Cha ching$$! [ May 05, 2001: Message edited by: BLKMGK ] Quote Link to comment Share on other sites More sharing options...
pparaska Posted May 6, 2001 Share Posted May 6, 2001 Jim, I don't remember saying that the dimmer switch worked the ground - it doesn't, I agree. The fuel level sender "grounds" the fuel level gage, and the temp sender "grounds" the input to the temp gage though, maybe that's what I wrote earlier? BTW, where did you get blue bulb condoms? The tach and speedo are held in with two wing nuts up behind them. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 6, 2001 Share Posted May 6, 2001 Pretty cool, that'll work! I did something similar, but I used two pieces and welded them together (to form a T), this looks much easier. Good job. Lone Quote Link to comment Share on other sites More sharing options...
pparaska Posted May 6, 2001 Share Posted May 6, 2001 Jim, pretty cool! I first made up a bracket but then decided to do exactly what you did! Great minds think alike, huh? I'm going to go back and put my gages in the stock bezels, as now they just sit in the holes and flop around (waiting for me to do something about that. Then again, I don't know when that'll happen, as the car is still in paint jail! Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted May 7, 2001 Author Share Posted May 7, 2001 I'll have to hunt for the dimmer comment, I must have been half asleep that night ! Got ALL of the center gauges done today - just have to power the fuel gauge and wire it to the sender, I've already started that Found the wingnuts, ouch! One was really tight and otugh to get at. Both of those gauges have been removed now! However, which color wirebulb goes to high beam and brake? They popped out before I could see and I need to know in order to wire those up (sigh). Bue bulb condoms? A Sharpie blue marker is what I used to color the bulbs. As of yet I do NOT know how it'll look but I honestly expect it'll be okay and not hard to change if I don't like it Speedo and Tach need to be ordered - that will be early this week I hope, not quite sure how I'll mount those but foam tape might be called upon this time... Quote Link to comment Share on other sites More sharing options...
Guest 73LT1Z Posted February 11, 2006 Share Posted February 11, 2006 Jim' date=' I don't remember saying that the dimmer switch worked the ground - it doesn't, I agree. The fuel level sender "grounds" the fuel level gage, and the temp sender "grounds" the input to the temp gage though, maybe that's what I wrote earlier?[/quote'] I'm wiring my Classic Instruments Cobra reverse-wind speedometer, and it has an input for +12V for illumination only (integral ground for the bulbs with the gauge). I've looked over the Datsun wiring harness schematic in my '75 service manual & it looks like two wires to all the dash bulbs: Green/white: +12V also goes to parking/tag lights Red/blue: -12V, connects to resistor for illumination control The parking & exterior lights have black wires to ground. The odd part is the schematic appears to be wrong because the other side of the resistor goes to a black wire that goes to the glovebox lamp... and nothing else. It appears they left out a connector where the black goes to the remaining black wires in the harness, otherwise none of this stuff would be grounded. Based on this layout, it appears the dash bulbs are dimmed via ground, otherwise the parking lights etc. would dim with them. At this point, it looks like I'll have to re-wire the dash gauges so I can use the resistor on the + side so the speedo bulb will dim with the remainder. Quote Link to comment Share on other sites More sharing options...
Lewis Maudlin Posted February 12, 2006 Share Posted February 12, 2006 OK, I removed my gauges. I used a phillips screwdriver to remove the two screws holding the gauge guts in the mounting. I used a dremel to cut big holes in the back of the gauge so that the lines would feed without restriction. I pushed the guts and plastic out of the gauges and inserted the autometers. I hooked up the original wiring to the gauges so the lights worked. I have done this on two different Z's. No bending or tools needed other than something to cut the back of the stock gauge housing. Quote Link to comment Share on other sites More sharing options...
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