Using aftermarket gauges question

[Georgia Flash]

Hi guys, today as I sat on a little stool in front of my Z trying to do what the good book (JTR manual) says in regards to separating the wiring harness it dawned on me that I will be using aftermarket gauges. Now the question I have is this, will I be able to use the old wiring for the new gauges or am I going to have to run another wire instead?

Also something that has been bothering me about the JTR manual is that it is geared more towards the 240 than the 280. There are more than a few pics in there that only show how to do it on the 240. It makes reference to the gobs of relays and wires that you will not need with the 280 but doesn't bother telling you which ones to disgard. Any help would be appeciated.

[Guest Anonymous]

I do not know any thing about wiring in aftermarket gauges to the 280 Z wiring harness as you asked but facing the same wiring dilemna in the engine compartment with the two fusible links in the big white hot wires which keeeeeeep doubling back and going here and there. With the JTR diagrams and poorly written instructions while sitting on my folding chair, I was able to sort out and dispose of all the un-needed wiring which was substantial.About 4 hours of cutting and labeling. I just made a copy of page 9-6 in the JTR 7th edition and used it as a reference as I worked on the wires.I think that your tach,oil,water and volts are left totally intact where you can hook up to aftermarket units and if not the aftermarket units will come or should come with wiring installation instructions to by pass the Datsun gauges. Oil and water can be had in mechanicl operation. I always bought and preferred mechanical gauges over the electrical controlled units. I would not deviate from the JTR diagrams unless you are good friends with an electrical wizard. I can wire a little but I am not going to venture into strange new worlds. I plan to use the stock gauges and obtain some of those $50.00 (overpriced) overlay white faces. After reviewing th JTR wiring section the fourteenth time it does get simpler and now I see my biggest problem is to where to wire in the fusible link that I will reuse from the Datsun unit.

[Georgia Flash]

(Sigh) I will go back and read some more

[pparaska]

One way out of the gage issue is to just use mechanical water temp and oil pressure gages. Yes, unless you go to an expensive European aftermarket gage, you are probably left with using two pods for just these two gages, and losing two other gages in the process (volt or amp meter and clock).

 

I used Autometer gages: oil pressure, water temp, and fuel level (use the old Ford sending unit version and see my web site on how to "calibrate" it to the Datsun sender). I put the oil gage in the left hole, water temp in the middle, and fuel level in the right hole.

 

Lone showed one of those volt meters that plug into the cigarette lighter lately and that's a way to get the volt meter back. I figure what ever stereo I buy will have a digital clock in it anyway, so the loss of the clock is no biggie.

 

By using mechanical oil and water gages, you don't have to worry about the wiring and you get more accurate readings anyway.

 

Just my $.02

[Georgia Flash]

Thanks Pete,

That's what I was kinda wondering about. It seems that would be the easiest thing to do and not worry about having to trace down all of these wires. I aready have the fuel gauge (auto meter pro comp ultra lite) and will be ordering the rest of them some time in the near future. Another thing that would make wiring the gauges easy would be to just by the correct auto meter gauge for the block you were running. I know the JTR book says something about fabricating an old chrysler swith and drilling out this and drilling out that just so you can hook up the Datsun gauges. Yeah I'm kinda like you when it comes to the clock issue, my new stereo should take care of that problem, and I saw the digital volt meter on hybrid just the other day. Ah lots of choices to choose from.

PS.

How exactly does the mechanical gauge work? I would assume by the term mechanical that it doesn't use a sending unit? Is this right?

[pparaska]

Mechanical = no wires.

 

The oil pressure gage uses a line (preferably a braided hose, I used copper tubing) from a fitting like on the back of the block near the distributor. It just runs to a fitting on the back of the gage.

 

The mechanical water temp gage has a tube that's attached to the back of the gage that runs to a fitting (included, 1/2" NPT with Autometer) that goes into the intake manifold where a sending unit might go.

 

You just have to be careful you don't kink the lines when installing them. I think on the water temp gage you have to use the full 6 feet of tubing (you can't cut it), so you would probably coil it up under the dash.

[Jeff]

If you go the mechanical route definetly take Pete's advice and run copper tubing for the oil pressure gauge. I used the cheap clear plastic stuff once and oiled down the back side of my dash one day when the tubing blew. What a mess

[Georgia Flash]

Coool I will have to consider doing that. If I decide to go electrical with the auto meters and use the chevy sending units can I run the wires through the datsun fuse box or should I just use an inline fuse?

 

I guess what I'm getting around to asking is would it be easier to get a painless wiring kit for my car and discard the old datsun harness? It just seems like it will be a pita trying to figure out what I need to keep what I don't and so forth. Thanks in advance guys. (((If you haven't figured it out yet, I'm afraid of the wiring monster!)))

[Guest scca]

skip the copper line as well and just go to braid for the oil... about $30 at max to do that line...

i also had a old plastic oil line crack and it sprayed all over the valve covers..

 

i am currently going to install 5" monster guages in my car already did the oil and water last year, kept stock fuel guage

 

with a car i did before we put all autometer and i put hte fuel guagein the glove box.. it had a boost guage so no room for all- fuel is least used