Custom M body gauges

brotherGood

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20160925_134440_zpsklyjcufw.jpg


Well, I've been saying I was going to do this for years, and I finally started today. I used a 2" hole saw initially to open up the side pods enough to fit the gauges into. While they fit, it was extremely tight, and I wanted some breathing room for when they get hot..so I went to a 2 1/8" hole. Mounted them in using the mounting hardware that came with the gauge, just gotta figure out wiring. I'd love to just tap into the factory stuff, but Im not sure if I can or not.

I also still need to fab up a plate to mount the big gauges, as the egg shape doesnt hold them for nothing..plus it looks bad..lol.

Im thinking I'll paint the bezel when Im done, and retouch the chrome around the vent, stereo, and HVAC control head..just not sure what color.
 

DCAspen

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Cool,Working on some custom gauges myself,Trying to keep it stock looking.
 

BudW

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I haven’t worked on aftermarket gauges in some time – so not sure what they are using now.
When I was working with aftermarket gauges, they all used 12 volts.

Pretty much all Chrysler gauges use 5 volts – so without some serious gauge re-calibration – you most likely will not be able to use the original sensors.
The wiring should be able to be used, though.


I like using 5 volts – for you do have a steady voltage.

12 volt systems – will not have a steady voltage (could range between 10 volts to as much as 15 volts).
The voltage difference CAN and WILL make your gauge readings off due to the voltage differences.
A crude example: ever notice how dash lights brighten as engine is at higher RPM than at idle? That is roughly a 2 volt difference.

Personally, if I’m going through the trouble of installing gauges, I want them to give accurate readings.

Note: you can add a voltage regulator that regulates output to 12 volts – but most voltage regulators don’t work or won’t work correctly if voltage goes under 12 volts (or whatever your target voltage is).

BudW

Edit: The Mopar 5 volt system has it's own problems - so not saying it is "best", either.
 
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brotherGood

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If I need to increase voltage, wouldn't I need to rewire? Do I need to increase the fuse size?
 

80mirada

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There is a voltage regulator on the back side of the gauge cluster that steps the voltage down to 5 volts. You should be able to use the input voltage off of it to run aftermarket gauges without any problems. Your new gauges won't be drawing much amperage, so I doubt there is a need to use heavier wiring, or a larger fuse
 

BudW

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I doubt there is a need to use heavier wiring, or a larger fuse
I agree.
Your gauges do not use much power – so wire size (or fuse size) is not important.

There is metal plug-in 5 volt voltage limiter on back side of left side gauge pod (not sure of exact name).
Voltage Limiter.jpg

M Bezel.jpg

If you will not be using any of the factory gauges, then you can remove that regulator and bypass.
If you are still going to use any of your original gauges, then you will need to keep it in place.

12 volts will instantly fry a 5 volt gauge (I do mean instantly – I do have experience burning out gauges (plural) – accidently of course).


Side note: on older Mopars, ‘60’s etc., I highly recommend replacing the voltage limiter (Chrysler calls it a voltage limiter, not a voltage regulator) with an updated electronic version – like one made by RTE (Main Page - rte ) - for older gauges are getting real hard to find.

I bought a pair of these for my ’77 wagon and ’86 5th Ave – after working (a lot) on older gauges and the reliability of the mechanical voltage limiter. Yes – a tad pricy, but cheaper than buying all new gauges.

BudW
 

BudW

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Are you replacing the fuel gauge, as well?
If you are replacing all gauges, including the fuel gauge, then I don’t see why you can’t tap into the 12v side of the voltage limiter.

The speedometer doesn’t care about voltage.

If you are leaving the fuel gauge in place then you may need to re-think what goes were power wise, for it will need 5 volts.


What would be very cool is if someone could make a M-body drop in meter to go in place of the fuel gauge that would be ¼ round fuel gauge and ¾ (or 2/3) round tachometer – but for some reason, I just don’t see that happening anytime soon.

I think it is interesting that mid/late ‘60’s/early '70’s cars had Tachometers (as an option).
The late ‘70’s and ‘80’s had nothing for tachometers (few and far between had them).
Now when you get a car, it pretty much comes with a tachometer standard (not much choice in the matter).

BudW
 

brotherGood

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All gauges are being replaced. The fuel is going into a small hole to the left of the wheel
 

brotherGood

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Ok, Im bringing this back up because I've got a question. Im currently looking for the sending units to get this moving forward. I installed the oil sending unit before even installing the engine..so I have that one. I have a brand new o2 sensor, i'll have to weld a spot in my exhaust for it though once I go with headers, or just look at a different gauge. Im assuming the volt gauge just wires into the harness. So, Im looking for the water temp sender and the fuel sending unit. My question is..are they dependent on the application, or will the unit for the gauge work for the car?
 

80mirada

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You will need the correct senders for the gauges you use. Aftermarket fuel gauges are available to work with the stock sender, or you can buy a variety of different aftermarket ones. Stock Mopar is like a 70-10ohm (I am going from memory so I may reverse numbers). Voltmeter require being wired to the charging circuit .
 

kkritsilas

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Are you replacing the fuel gauge, as well?
If you are replacing all gauges, including the fuel gauge, then I don’t see why you can’t tap into the 12v side of the voltage limiter.

The speedometer doesn’t care about voltage.

If you are leaving the fuel gauge in place then you may need to re-think what goes were power wise, for it will need 5 volts.


What would be very cool is if someone could make a M-body drop in meter to go in place of the fuel gauge that would be ¼ round fuel gauge and ¾ (or 2/3) round tachometer – but for some reason, I just don’t see that happening anytime soon.

I think it is interesting that mid/late ‘60’s/early '70’s cars had Tachometers (as an option).
The late ‘70’s and ‘80’s had nothing for tachometers (few and far between had them).
Now when you get a car, it pretty much comes with a tachometer standard (not much choice in the matter).

BudW

Speedhut can do that (speedhut.com). It would be a custom order, but they can do tachometers with sub gauges, and they have off the shelf GPS speedometers with tachometers. The GPS speedometers would do away with speedometer gears or needing to worry about rear axle gear ratio or rear tire diameter changes. The speedometers are available in in MPH or KPH, and have the turn signal indicators as well. The odometer readout is in an LCD display though, so some may not like it.

A while back, member by the name of NoCar340 had figured out what the factory font was for the J Body factory gauges, and Speedhut was open using them on any gauge they made, so the replacement gauges would look factory. You can, within limits, even choose the color the gauges light up in at night.
 

brotherGood

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Wow, I forgot all about this thread...probably should update it.

Im onto a new idea for the gauges. Couldnt figure out how to address the main pods and found someone who had made his own custom bezel. Contacted him, had one built and realized when it got here that the center pods he cut were too big. After fighting with trying to make it work (and failing) I was talking to a friend of my father-in law who has some wicked Camaros. He asked why I didnt use solid wood and paint it. I kinda laughed at it, and he said hes got a wood bezel in his Z28 and its lasted 30 years at this point..and nobody realizes its wood until he says something about it. Once the weather gets warmer, I'll plug the holes in the firewall from the heaterbox removal and cut one up. Then comes the struggle of rewiring it all.
 

brotherGood

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Here's where I have it so far. The speedometer isn't working for some reason, nor is the water temp or volts. Also need to finish the bottom half (stereo and lights) but at the point..I'm just happy the hard part is done...

..I think.

20180616_135350.jpg
 

BudW

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I like it.

You are getting rid of, err, not going to use the two A/C vents?
BudW
 

brotherGood

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Correct..a part of me wanted to keep them, but part of me said forget it.. haha

We see which part won
 

Duke5A

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I'm having a hard time seeing what the finished product is going to look like. The spacing and location of the gauges doesn't symmetrical either. :eek:
 

brotherGood

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It isn't. This was the rough layout..which is why it is out of wood. I plan on going back through and lining everything up properly and using metal.
 

BudW

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I plan on going back through and lining everything up properly and using metal.
Great idea.

There are two gauges hidden behind the steering wheel – so I was hoping you weren’t “set” on keeping the gauges at that location.

It might not be a bad idea to find both sides of a multi-pin electrical connector (for however many pins you need) so if you need to remove the new cluster, a quick disconnect is all that is needed.
Going to a pull-a-part makes this job easy – for it doesn’t matter what brand car you get both plugs from – just if they match, and you have a length of wire to work with.
BudW
 
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