Rewiring my EFI Magnum - 1970 Dart Swinger

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If it was me, I would go to a wrecking yard and clip the plug off whatever GM model the switch came from. I would bet you could even de-pin it and slide your wires right into it. I just like having the plugs, wires don't get crossed later and less chance of them coming loose. But $35 is way too much to spend unless they aren't available in the yards.
That would be the way to go, next time I'm at a yard. I like the connectors for the same reason!
 
Scope creep is something that happens in my work where you start a project and things keep getting added to the project along the way. "While I'm in there, I might as well do the XXXX too..." I'm suffering from some serious scope creep right now.

Ever since I did the EFI swap I had always run a shunt wire from the alternator to the battery, so the ammeter wasn't doing anything. I decided I wanted tie the ammeter red and black together and get it totally out of the mix. Well if I'm going to remove the cluster I might as well see if I can convert the ammeter to a volt meter, right? Also, I bought some LED strip lights several years ago thinking I would try to improve the lighting in the gauge cluster. Might as well do that too. My fuel gauge was getting a little wonky lately, only reading when I had the headlights on, so hopefully I can figure that out while I'm in there.

The Sunpro volt meter is apparently the one to use, but I did some reading and saw some guys say Bosch bought Sunpro and rebranded the products. This has the same 8215 in the part number that the Sunpro does, so I thought I would give it a try. Free returns through the jungle website anyway, so I wouldn't be stuck with it.

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BTW, as a guy that ordered mail order parts through magazine ads back in the day, the jungle website is amazing. Ordered this at 10:30 pm, Friday night (Good Friday, which is a holiday in Canada) and delivered noon on Saturday.
 
Trying to figure out where to drill the holes for the screws that held on the old voltmeter face and will hold on my ammeter face. Notice I had to grind a bit on the centre of the gauge cluster so the little counterweight at the bottom of the needle will clear. Also needed some more clearance on the ammeter face. And I'll have to do something about the colour on that pointer. It doesn't look too far off in the pics, but in person it's way more red than my factory pointers.



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I got the gauge together, now let's see how it works. Looks like straight up and down at 13.8 volts.

It's a little weird that it's at the bottom of the centre mark when down 0.4 volts, and at the top of that mark when up 0.9 volts. I don't know why it's like that, but it doesn't really matter to me. I just need to know if the voltage is way to high or way too low and this will be fine for that. I know some guys put the numbers on the ammeter face but I don't really care about that, again, I just need to know if the voltage is too high or too low.


Gauge at different voltages 3.jpg
 
Got it back in the cluster and doing some bench testing. Here I am at about 13.5 volts, with some dazzling LED strip lights! I have had green LEDs in the factory bulb location for years and they definitely help, but the gauges are still super hard to see with any ambient light (i.e. street lights). We'll see how this works out, it can't be any worse.
Shout out to @moparmat2000 for his threads on putting the strip lights in the cluster and giving me the idea.


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I painted the volt meter gauge pointer to match my other pointers. Last time I had the cluster apart (when I fixed the fuel gauge) I painted them all as close to the correct colour as I could get. I used fluorescent model paint, which adds a bit of luminescence to them. Not like that radioactive paint they were using on watches in the early 1900s, but it's the best I could do.

I got the orange I was looking for by mixing these two colours, about 90% orange 10% red. Literally one drop of red in that little bottle cap of orange is perfect.


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Here are the colours before mixing. They're a little more washed out than usual since my test was just on plain paper, but you can see they're not close to the tach. As usual, pictures don't capture the colours perfectly. The red looks way closer to the tach colour here, but it's really not, the orange is closer. And the original red on the volt meter pointer doesn't look that bad, but it was.


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Got it back in the cluster and doing some bench testing. Here I am at about 13.5 volts, with some dazzling LED strip lights! I have had green LEDs in the factory bulb location for years and they definitely help, but the gauges are still super hard to see with any ambient light (i.e. street lights). We'll see how this works out, it can't be any worse.
Shout out to @moparmat2000 for his threads on putting the strip lights in the cluster and giving me the idea.


View attachment 1716230614
That will work just fine. Will be plenty bright at night.
 
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When I bench tested the cluster with the lights off in the garage I found some of the lighting was too bright. For starters, on the tach between the 2000 and 4000 rpm area the light was super bright. Probably just the angle of the LED strip or just too many lumens. When I looked at the back of the cluster I saw there are sections where the factory had the outer perimeter on the back of the lens blacked out. The areas where the tach was getting washed out didn't have that blacked out, so I put a bit of flat black paint on there (it's still wet in this picture):

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There was also a section between the ammeter (now voltmeter) and the fuel gauge where one of the LEDs in the strip lights was shining right through and causing a lens flare effect. For that issue I found the LED that was causing the lens flare and I marked it up with a black sharpie. That worked out perfectly, here is the result. The tach is a little brighter than everything else, but it's not as bright as it looks in the pic. And you can just see a bit of the flare above the E in the fuel gauge, but it's not glaring like it was before.

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Here's today's good guy alert.

The Magnum oil pressure sender uses the same resistance values as the old gauges, so I decided I would try get the factory oil pressure gauge working. I have a mechanical Autometer gauge, but I figured since the factory gauge is there and I already have a "T" on the oil pressure port in the block I might as well give it a try. Well, it turns out my gauge was dead. I checked to see if anyone on the forum had posted one for sale recently, and sure enough @4spdragtop did.

I reach out and ask him about it, and what does this guy do? He tests the gauge he has and just sends it to me, no questions asked. What an awesome guy!!

That really helps restore my faith in Mopar guys. Back in the 90s when I started putting this car together I feel like Mopar guys used to help each other out like that. My brand X buddies would always complain about how everyone is trying to make tons of money on brand X parts, but I always had Mopar guys willing to let stuff go cheap if they knew I would use it. In recent years that has changed, it seems now everyone is looking for top dollar for their parts. So, many thanks to Steve for helping me out and restoring my faith in the Mopar community!

Here's the gauge he sent me before I painted the pointer to match my other gauges:

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Here's how my cluster is wired. Definitely some non-standard wiring here:

- External voltage regulator, instead of the one that would be in the fuel gauge. My fuel gauge was dead so I did a fuel gauge replacement a few years ago where I put the rallye face and pointer on a gauge from a 70s Jeep; same pod as the Mopar gauge, the same resistance values, and the same spacing between the posts.
- Jumper from the fuel gauge power over to my "new" oil pressure gauge.
- 12 volt power from the additional connection on the external voltage regulator for my voltmeter.
- Notice the wires coming out of the cluster for the LED strip lights.
- Those are wired into cluster lights you see on the right (left side when looking at the gauges). When I did the fuel gauge mod I had that pin for the cluster lights break off the circuit board. It was totally destroyed, so I put those bulb holders in the holes and connected them to the wire that feeds that pin. And for this update I wired the LED strip lights into that same power connection.


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Thanks for the mention Mike! Lol I just realized I have an old used oem sender I should have put in the box with it.
Nice work! The guages dash fsce is constantly "in your face" so the better they work and look the better.
Here's today's good guy alert.

The Magnum oil pressure sender uses the same resistance values as the old gauges, so I decided I would try get the factory oil pressure gauge working. I have a mechanical Autometer gauge, but I figured since the factory gauge is there and I already have a "T" on the oil pressure port in the block I might as well give it a try. Well, it turns out my gauge was dead. I checked to see if anyone on the forum had posted one for sale recently, and sure enough @4spdragtop did.

I reach out and ask him about it, and what does this guy do? He tests the gauge he has and just sends it to me, no questions asked. What an awesome guy!!

That really helps restore my faith in Mopar guys. Back in the 90s when I started putting this car together I feel like Mopar guys used to help each other out like that. My brand X buddies would always complain about how everyone is trying to make tons of money on brand X parts, but I always had Mopar guys willing to let stuff go cheap if they knew I would use it. In recent years that has changed, it seems now everyone is looking for top dollar for their parts. So, many thanks to Steve for helping me out and restoring my faith in the Mopar community!

Here's the gauge he sent me before I painted the pointer to match my other gauges:

View attachment 1716234199

Here's how my cluster is wired. Definitely some non-standard wiring here:

- External voltage regulator, instead of the one that would be in the fuel gauge. My fuel gauge was dead so I did a fuel gauge replacement a few years ago where I put the rallye face and pointer on a gauge from a 70s Jeep; same pod as the Mopar gauge, the same resistance values, and the same spacing between the posts.
- Jumper from the fuel gauge power over to my "new" oil pressure gauge.
- 12 volt power from the additional connection on the external voltage regulator for my voltmeter.
- Notice the wires coming out of the cluster for the LED strip lights.
- Those are wired into cluster lights you see on the right (left side when looking at the gauges). When I did the fuel gauge mod I had that pin for the cluster lights break off the circuit board. It was totally destroyed, so I put those bulb holders in the holes and connected them to the wire that feeds that pin. And for this update I wired the LED strip lights into that same power connection.


View attachment 1716234201
 
Did I mention the only reason I took out the cluster was to see if my tach would support 4 cylinder mode? (Because the Magnum computer send a 1/2 tach signal). Turns out it doesn't, so I'll splice into the coil wire.

This opened up a huge can of worms... the old "while I'm in there I might as well..."
-Get rid of the ammeter and replace it with a voltmeter. I had to get a voltmeter.
-Put the LED strip lights in the cluster. I had these already.
-Get the factory oil pressure gauge working. I had to source one because mine was dead.
-Take out the wiper pivots and grease them up (smart move, they were a bit stiff).
-Fixed a few hacked up wires that I had ignored previously.

It was all pretty successful, but make no mistake, I have more hours into this than I would care to admit. Especially that voltmeter conversion, that's not for the faint of heart.

Oh yeah, and I managed to screw up my headlight switch. The spring resistor for the dimmer somehow got some debris behind it and it got caught on the thing it connects to. I've had a spare headlight switch for years so I tried to use it, but it turns out it's for a later car and won't work. I put it back together with the damaged switch, but I'll source another one soon.
 
This is not a new picture, this is from when I did the engine swap back in 2021. Even after doing my best with a coat hanger and various brushes, I eventually ended up with some sediment in the coolant that I wasn't happy with. The engine never got hot on me, but no one likes a dirty cooling system, right?

I didn't take pictures of this, but I got the car out into the driveway and flushed the cooling system. I managed to get some more sediment out, but we'll see what the system looks like after a few thousand miles.

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Cleaning up the valve covers so I decided to re-adjust the rockers. Well look what I found...

Anyone near Caledon, Ontario have a spare 5.2 / 5.9 / 3.9 pushrod lying around?

I inspected everything else and it's all ok. Just one bent pushrod.

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