240z Charging system upgrade

[rejracer]

Hey there hybrid.

 

Attached are a couple of wiring diagrams I made up. The first is the OEM setup from a 72 USA Z. The second is what I am doing to it.

 

So far I have got as far as getting the alternator installed and functioning. I am using a 200 amp Alternator from Alternatorparts.com which does away with a lot of unnecessary wiring. I still have the ammeter installed, but it's essentially out of the loop as the original wire going to the alternator is not connected to anything at this point.

 

The purpose of reconfiguring the charging system is to enable a higher output alternator to be safely used, replace fusible links with circuit breakers, and replace the ammeter with a voltmeter.

 

Instructions:

1. install aux power and ground posts. I will install them below the battery tray on a fabricated bracket.

2. Make new battery cable assemblies, each cable assembly is to connect the Battery, Starter, alternator and Aux Posts. Positive and negative cable assemblies should be made out of 2ga cable to all devices. I made my own

3. Install 40 amp circuit breaker to aux power post(APP) and APP to fuse block using white wire.to power Horn and Hazzards

4. Install 60 amp lighting circuit breaker to APP and Circuit breaker to WR wire originally connected to Alternator to power Running and interior lights.

5. Bridge ammeter connections together, remove as much of the wire as possible. Ensure ignition switch and combo switch retain power.

6. Install volt meter. Wire the existing fuel gauge YR wire, jump it to the + side of the VM and the + side of the VM charge indicator lamp. From – side of the VM, run a new brown wire (18 gauge) to the L terminal on the alternator. From the – side of the charge indicator lamp, run a black wire to the Fuel gauge/VM sending unit ground.

7. Install Alternator, wire up new Alternator connectors.

 

 

 

Enjoy

[RB26powered74zcar]

Nice job on the diagrams!

[rejracer]

Here are the pictures of the install of the CS144 Alternator.

 

There are 4 wires on the pigtail. Only 2 of them are used. The red wire is the voltage sensing wire, it gets connected directly to battery voltage. I suggest a 14ga wire direct from battery to this terminal. It is this wire that will enable the alternator to produce clean stable voltage. One wire alternators have voltage drop across the charge line, thus they will never be capable of producing stable voltage at high loads.

 

The Brown with red stripe gets connected to switched voltage through a resistor. It is this wire that turns the alternator on. When the alternator is charging this alt produces 12v at this terminal. When the alternator is not charging this is grounded. This "switched" ground is what makes the charge light work.

 

 

Here is a shot of the tidy sealed connector. It's very easy to remove and solidly locks in place.

 

 

 

Notice the Alternator brackets. This is a bolt in installation, no hard modifications needed. I used the Alternator parts.com universal mount kit part number A285

 

 

Here is a better shot of the alternator mounts. They are simple offset brackets. The positioning of the lower mount could be better, Nigel's modified lower mount would put it in a better location. The downside to this is it limits the range of adjustment the alternator has. The plus side is it's a bolt in installation, somewhat adjustable, and very strong.

 

 

Here is the upper mount. I used the stock upper mount but had to reduce the offset to have it line up correctly with the alternator. A hammer and vice worked just fine. I also had to slightly increase the inside width where the locking bolt passes through. A file worked fine.

 

 

 

 

Parts used in this installation:

CS144 200amp standard voltage regulator alternator (included the harness / plug)

 

A285 dual foot alternator bracket

 

Nissan small diameter pulley. I got this from the failed alternator, one from Z specialties.

 

Napa 25-7350 or equivalent belt.

 

Modified stock upper bracket

 

Custom 2 gauge battery cables, run directly from battery to alternator.

 

280z volt meter

 

Misc wiring as needed.

[rejracer]

Now for replacing the ammeter with a voltmeter.

 

I sourced a 78 280z volt meter/fuel gauge pod. After reviewing the factory 280z service manual to glean how they intended to wire it up, I decided to tear the gauge pods apart.

 

I noticed some physical differences between the fuel gauges. 240z on the left, 280z on the right. the 240z gauge interferes with the 280z rear housing, it touches the transparent green bubble on the inside of the gauge. I decided I did not want the green tint to the guages, so I removed it. This added enough clearance to mount the 240z gauge in the 280z gauge pod.

 

And another view of the guages themselves:

 

Notice the difference in font between the 240z (left) and 280z faceplates. I will probably keep the 280z faceplate as it's in better shape. Also notice the 280z face plate overlaps OVER the 280z volt meter. The 240z fuel gauge faceplate overlaps UNDER the stock ammeter gauge faceplate.

 

The front bezel design is different. I will need to stick with the 240z bezel (left) to make this work. I am also replacing the factory plastic cover with glass. I had a local glass shop cut them out for me. I will reattach the inner bezel to the outer bezel using #2x.25 wood screws used with 3mm washers. I will drill a hole in the mounting tangs for the inner bezel to ensure all goes well.

 

The steel frames of the 2 gauge pods are similar, same mounting for the fuel gauge, of course it's different mounting for the Volt meter, and the provision for the charge light.

 

 

The components I think I will end up with is going to be:

280z metal frame

240z fuel gauge

290z fuel faceplate

280z volt meter and faceplate

280z ilumination light

280z charge light

240z inner and outer bezel, with glass insert.

 

I am in the process of stripping the metal frame down to bare metal as it's rusty. I am going to paint the inside of the bucket white, and then give it a coat with reflective paint. I will do the same for the inside of the inner and outer bezels, but refinish the visible portions in flat black. By removing he green illumination light bubble, and refinishing the inside white with reflective paint, I hope to brighten the stock gauge illumination up a bit.

 

If anyone has any insight to this upgrade, please chime in. In particular I would like to know if the 240z and 280z fuel gauges are the same electrically.

 

As far as the wiring goes, I will connect the volt meter to ignition voltage, and to ground. The charge light indicator gets connected to switched ignition voltage, and the other end to the brown/red stripe wire on the CS144 alternator.

 

The fuel gauge gets connected to the stock 240z connection points. I will try and use only the stock 240z connector. To my recollection, there is a position in the stock electrical connector that is not being used. I will use that position to run the wire from the charge light to the alternaor. If it's not available, I will just use a single insulated connector.

 

-Robert

[rejracer]

I Just cleaned up the pod frame/housings and repainted the bezels. here are the pics of how it turned out.

 

I used flat white paint coated with reflective spray. I did not like how the reflective spray turned out. I may strip the bezels down and redo them.

 

 

Here is how the driver facing side turned out. Believe it or not, there is glass in it in this picture. Duplicolor low gloss engine enamel was used. The low gloss paints dry much faster than the gloss.

 

The gauges mounted up.

 

The somewhat finished assembly.

 

The backside of the assembly. I was not concerned about paint finish on the rear portion.

 

I had a local glass shop cut the glass rounds for me.

 

 

Anyone know of a good bright white reflective paint? I would like a single stage rattle can paint, that is as reflective as a road sign, or better. As of now, the reflective spray I am using is a clear coating that turned the nice flat white paint to a yellowish color.

 

-Robert

[rejracer]

Hi all,

 

 

Auxiliary Power Posts from Waytek wire.

 

The mounting location. I chose this spot because I plan on moving my fuse box behind the strut tower, this is a good place to tap into power for all the power feeds. I will need to make a new mounting plate. I'm still deciding on keeping the existing and just welding in the circular plate, then redrilling the holes, OR building a new plate, and trimming the existing back, basically making it just an L bracket to mount the new plate. On the lower side I would tack weld in some brackets to bolt it together, making it nice and rigid.

 

The back side. When the power posts are in, I will recrimp the battery cable assemblies into a single connector. I will also ditch the 1/0 cable in favor of 2 ga to the starter. Essentially each cable assembly will be 3 runs of 2 ga wire from battery to Starter, Alternator, Aux Power Post.

 

I decided to test the 240z vs 280z fuel gauge. I set up a simple potentiometer wired in as a rheostat to limit voltage to the 2 gauges. It's not the most accurate test, but I think it's good enough to convince me that they are compatible. I will run the 280z gauge. Both gauges did full sweeps, at the same positions, same rate. I am satisfied the 280z gauge will work with the 240z sender.

[rejracer]

I finished mounting the power posts today.

 

Originally I was going to mount a square plate. Once I fabbed it up, I decided I did not like it. Unfortunately I had already cut the fender support bracket. So I recut the plate, and tack welded the lower portion of the bracket on to it for looks really. Then finished the holes for the power posts.

 

The finished product. I used masking tape and newspaper to tape it off before spraying the bracket down with duplicolor orange engine paint.

 

 

 

And the backside (frontside?)

 

 

 

Next up: Recrimp Battery Cables then voltmeter install.

[rejracer]

So I recrimped the battery cables. The old setup was several individual cables routed to the battery. I now crimped the individual leads into 1 terminal. Crimped terminals are better than soldered as if a serious problem arises and they get hot, they are mechanically attached to the cable, where solder could melt, and cables come apart.

 

Crimping in action, sunny day, forgot my hat, think i got a sunburn up there. Watch out when releasing these crimpers. I relased one and I did not slow it down enough, unfortunately the back of my and and the handle caught my chin. I spent the next 30seconds feeling for broken teeth, fortunately none! I have not had that sensation since high school.

 

 

Negative crimp done on battery side. I used (3) 2ga cables to the starter, alternator and Aux ground post, plus one 8ga wire to the factory chassis ground. The positive side only had the three main cables. The terminal is a 4/0 the cables fit in very snug, I think perfect for what I was trying to do.

 

The finished negative assembly. They are a lot of work to crimp. 2 crimps on each terminal, and it's everything I can do to get it crimped. The hydraulic hose is going to be the insulator for a bracket I intend on making for it.

 

I'm routing the cables under the motor mount. Below the motor mount will be a bracket to hold the battery cables. The bracket will be bolted to the block using the motor mount bolts.

 

Birds eye view. Looks much better without the old overflow tank mounted on the strut tower.

 

Circuit breakers installed, this eliminates the fusible link. The entire vehicle is powered through this little block. I'm not so sure on the quality of this unit. I consider this a temporary fix until I get the electrical center installed. If I were to run this more than 5 or so years, I would replace the bottom piece as it seems too weak. I may fabricate one out of fiberglass stock from McMaster Carr. Regardless, circuit breakers that auto reset! How cool is that? the 1st breaker is for the "white" wire where the fusible link used to be, I used a 30 amp breaker. The 2nd breaker is for the old alternator White/Red wire, which I used a 30 amp breaker, the last is for the headlights, and used a 20 amp.

 

New coolant bottle, from the turbo doner car. I need to get it mounted somewhere. Not much space with where I have my headlight relays wired up. I plan on ditching the hella fuse blocks in favor of the GM / delphi stuff. I will put the electrical center behind the strut tower. This is why I chose to mount the aux posts where I did. Once that is complete, then I think I will mount the coolant bottle where the hella fuseblocks are now. But I would also like to convert this car to a closed coolant system. Anyone know of a good small bottle to use for that?

 

Only thing left to do as part of this phase of the upgrade is to install the volt meter and tidy up the harness with some wire loom. This is a relief getting this done, previously I was driving it around unfinished (read firehazard).

[rejracer]

I did alternator tests today and I found the following voltages:

RPM Voltage no load. Voltage with 35 amp load. Tested on a stock L28 with L28 Damper, CS144 Alternator with smaller diameter alt pulley, and optima red top battery.

0 12.5 (this is stable state of battery with no load)

600 12.10 11.85

750 13.30 12.2

800 14.20 12.9 (I notice lights dimming here)

1000 14.35 14.15

1500 14.40 14.18

3000 14.44 14.22

 

I was taught (early 90's automotive electrical systems class) that nominal running voltage is 13.8 to 14.4 volts, and stable state for a fully charged battery is 12.6v. Anything above 14.4v is overcharging and possibly damaging the battery. I consider that reasonable results by today's standards considering the L28 runs a much smaller diameter pulley than on a GM V6 or V8. I did however set out hoping that this alternator would provide 14v at 750 rpm under a 50 amp load.

 

I also finished up the volt/fuel and oil temp guages. I basically refinished them, and fitted them with all stainless fasteners.

[deja]

Nice write up guys. BTW if you need to rebuild the CS144 I found these guys. They have everything you could possibly change in one of these alternators.

[rejracer]

Here are some useful links on finding information on the CS144 alternator.

 

 

Exploded View Diagram

 

CS144 Reassembly Instructions

 

CS 130 Service Manual

Yes CS130 is a different alternator, but it uses the same regulator as the CS144. For wiring it into a vehicle, the information is applicable.

[toofass4udoo]

Hey there,

Nice post. I have a question for you: I'm looking for a way to safely remove / replace the voltage regulator on a '71 240. I notice you don't show a voltage regulator on your modified drawings. How is the voltage regulator function replaced in your new set up? Honestly, I'm not even sure how the V.R. functions on the stock set up. It seems like the V.R. should be in between the alternator and the battery some how? Either way, can you help me understand how I could regulate the voltage to the charging system. Thanks,

[loy]

Voltage regulation is done internally in the alternator.

[toofass4udoo]

O.K. That makes sense. Thanks

[rejracer]

I ended up making a lower mount based on Nigels method.  I did not help or hurt the mounting either way.  For the larger case CS144 the lower mount needs to be lowered  and moved outwards.  The alternator still do not have as much adjustment as I would like. 

 

I'd say it's a wash either way for the mounts.  Nigels method is a bit cleaner but requires more work up front.  I think the brackets I used initially were a bit stronger.  I'll probably stick to the simpler Nigel style mount.