Alternator upgrade questions

[Negative Ghostrider]

I ordered a 240sx 60 amp alternator and v belt for the L16 to support future stereo and A/C aspirations, and to help address the dimming under normal loads. This is supposed to be a drop in replacement but I know the OEM alternator has an external regulator and this one is internal.

Is there anything special I should know about removing the regulator and wiring in the new alt or is it basically just point to point with lug connections? I'm guessing the wiring should upgraded. Would 8AWG be adequate or should I go bigger? Are there any fuse related things I should consider? 

Thanks! 

[Crashtd420]

I'll give you 2 bits of info....

 

 

And to bypass the regulator....

[Crashtd420]

Watch out for the electric choke relay....

If you have one you want to cut the yellow wire going to the relay and you can connect it to the white/blue...

 

Also good idea to use an old regulator plug to make the neccessary jumper....

Just make sure to follow the wire colors on the truck harness,  not the regulator... the regulator I had used different colors..

[datzenmike]

Unfortunately Crash that only works on the older 510 alternators. The 620 choke heater relay coil will be permanently wired ON even though the power to the heater is OFF with the ignition. I did this with my 620 and it was slow starting Monday mornings till I figured out the draw on the battery

 

 

Three things to do

 

1/ Cut the regulator plug wires off as long as you can.

 

Join the White/Red stripe to the White/Black wire.

Join the White to the Yellow wire.

 

Twisting them together with duct tape won't do, solder them and tape or heat shrink tubing, or crimp connectors. Remove any other wires. This plug just connects back onto the engine harness.

 

 

 

 

2/ Find the choke heater relay and unplug it. The conversion to eliminate the external regulator permanently powers the relay coil in the choke heater relay. It doesn't draw much but over a weekend it will kill the battery. Small metal box on passenger side inner fender near where the harness comes out of the firewall. Unplug

 

4 wires...

Yellow

Black

Blue/white

Blue/White

 

3/ Because the choke heater relay is no disabled a new power source for the choke heater has to be found. There are two wires to the back of the L series carburetors. Both are wrapped in black plastic sheathing but inside one is Blue for the choke heater and one is Red for the idle cut solenoid. Unplug and join the Blue wire to the Red idle cut wire leaving the idle cup connected.

[Crashtd420]

Also what v belt did you order?

I have , actually had the same altenator.. trying to fit a 90 amp right now, using a 7350 ... these are a tight fits in the truck but they do fit... you'll probably need to get the belt on before you bolt up the alternator....

[Negative Ghostrider]

Thanks guys. Very helpful. I will have a (authentic) auto choke weber on by the time this happens. Does that change the scenario? 

 

Crashtd420 - I got the 240 vbelt. I think I read is half an inch longer than the stock 620 belt or something, and should fit just right. 

[datzenmike]

An automatic choke heater on a Weber is an automatic choke heater on an Hitachi. Nothing changes.

[Crashtd420]

2 hours ago, Negative Ghostrider said:

Thanks guys. Very helpful. I will have a (authentic) auto choke weber on by the time this happens. Does that change the scenario? 

 

Crashtd420 - I got the 240 vbelt. I think I read is half an inch longer than the stock 620 belt or something, and should fit just right. 

The problem is something you need a shorter belt with the trucks..because the idler arm and the radiator outlet starts to get in the way when you try to tension it.. 

[klam07]

10 hours ago, Crashtd420 said:

Also what v belt did you order?

I have , actually had the same altenator.. trying to fit a 90 amp right now, using a 7350 ... these are a tight fits in the truck but they do fit... you'll probably need to get the belt on before you bolt up the alternator....

 

I just did an alternator swap using a 100amp sentra unit. Similar to the 240 I believe, but the ears are clocked at 12 o clock and not at an angle. Cant recall if the 240 was also dead across.

But anyhow, because the alternators are bigger it is a tight fit - I had to shave a little aluminum tab off the alt because it would touch the rad hose. Also used a plug on the idler arm to replace the grease fitting that stuck up.

 

I went to the part shop with my old belt and grabbed 2 v-belts that were the next 2 sizes up from original, I believe I ended up using the longer of the 2, then returned the middle length one.

Struggled to slip the belt on with the alt bolted in, so I had to slip the belt on and then bolt it up - very difficult, but the only way I could make it work.

As for tensioning, there was some room to adjust but it was down to the last ~1" of the tensioner arm before I maxed out, but it gave me good enough tension. The middle length belt might net more travel for adjustability but would make it that much more difficult to install, so I dont regret it. Ill be pulling and selling the engine long before any of those parts need changing.

 

 

As for the wire length vs gauge, does that apply to just the power wire? What about ground? Im using the same dinky ground from the original harness to the back of the alt and Im wondering if I need to beef it up. Its been running fine with no issues so far, but still.

[datzenmike]

These are basically the same problems I had with my truck using any of the Datsun car 60 amp alternators. Idler arm grease fitting, belt on first then mount the alternator, tight clearance to the hose. It was the same with the Plymouth K car 90 amp I tried later. 

 

On my 710 the idler arm is not a problem but the Altima 100 amp (probably the same physically as the Sentra) I had to grind away some of the block mount so the alternator could swing closer to the block to get the belt on.

 

The alternator does have a black ground wire but can ground through the case to the block. When I got the alternator I took everything including the ground and it's not that large a gauge, however the power wire was larger than the 710's stock positive cable on the battery!!! The easiest way to connect it to the positive was to simply put a lug on it and put onto the starter lug. It looked silly being larger than the battery cable so I went to the wreckers and got a set of GM side mount battery cables. The ground was long enough to fit one of the starter mount bolts.

 

Power wire left and old battery cable right

 

Much larger GM positive battery cable (red tip) Originally I had a battery with top posts and side mount but retired it for a free though slightly used side mount only so batery and cables are a nice up grade.

[Negative Ghostrider]

Ok. I have a couple of potentially dumb questions. I'm trying to get the alternator installed soon and a previous owner rattle canned everything under the hood black and got overspray on wires, relays, everything, so identifying stuff is problematic. The voltage regulator is the unit over the wheel well, right? Or is it the one back by the firewall? 

 

 

After that it looks like the positive "A" lead goes to the starter, and the ground "E" lead goes to the battery negative. My engine bay has been torn apart long enough that I don't recall where my chassis ground was. What's the usual location? 

 

Thanks. 

[datzenmike]

Yes, it's the big one with 6 wires.

 

Output from the alternator can join the positive battery cable at the starter lug. This is the easiest.

 

The alternator will ground through the case to the block but there is a black wire on the harness that can be bolted to the case. The chassis ground on the sheet metal is usually another smaller black wire connected to the negative battery cable and near the battery mount. If you can't find it any home made 8 or 10 gauge wire from the engine block or head to the firewall will work. Crimp lugs on the ends.

[EDM620]

Bad grounds are the root cause of many electrical gremlins. Make sure your ground wire is solidly crimped and secured to a nice cleaned bare metal spot - you can paint over after.

[Negative Ghostrider]

On 7/5/2020 at 11:39 AM, datzenmike said:

 

Three things to do

 

1/ Cut the regulator plug wires off as long as you can.

 

Join the White/Red stripe to the White/Black wire.

Join the White to the Yellow wire.

 

Twisting them together with duct tape won't do, solder them and tape or heat shrink tubing, or crimp connectors. Remove any other wires. This plug just connects back onto the engine harness.

 

 

 

Hey Mike. Just wanting to make sure I don't F this up. Your pic is just of the male end of the plug and only has the 4 wires in question but I'm assuming I still need the yellow and white/blue wires connected though. Otherwise that male plug is just 2 jumpers plugged into a dead regulator. Thanks. 

[datzenmike]

The plug in the picture is from the actual mechanical regulator. When done this plug connects to the engine harness.

 

Cut the regulator away leaving the wires long enough to work with. Join the white to the yellow and join the white/red and white/black. That's all there is to it.

 

The other two wires Black is ground and White/Blue is power from the fuse box, neither are needed so I pulled the pins with the stubby wires out of the plug so they can't cause any problems.

[Negative Ghostrider]

59 minutes ago, datzenmike said:

The plug in the picture is from the actual mechanical regulator. When done this plug connects to the engine harness.

 

Cut the regulator away leaving the wires long enough to work with. Join the white to the yellow and join the white/red and white/black. That's all there is to it.

 

The other two wires Black is ground and White/Blue is power from the fuse box, neither are needed so I pulled the pins with the stubby wires out of the plug so they can't cause any problems.

 

OK. So I am cutting the end off the regulator (red) doing the 2 splices then connecting it back to the harness (yellow), yes? I think I got confused because your plug looked different. 

 

[Negative Ghostrider]

I have the alternator fitted. It's a model R111307A from autozone, which is a 60A that fits various Nissans including the 720 and I think a 200 or 240. I ordered it based on a thread in here that I read but can't seem to find now which said it was drop-in with a v belt from the associated car. Anyhow, I was able to get it in and sitting pretty well by just flipping the upper bracket over. The belt is just a hair too short or else the top of the alt will rub on the radiator hose. That's easily remedied. The more pressing concern is that the pulley sits about 1/8" further forward than the crank and cam pulleys. Is that enough to cause an issue? 

Edited September 18, 2020 by Negative Ghostrider

[datzenmike]

16 minutes ago, Negative Ghostrider said:

 

OK. So I am cutting the end off the regulator (red) doing the 2 splices then connecting it back to the harness (yellow), yes? I think I got confused because your plug looked different. 

 

 

Plugs changed often. The wires were generally the same.

 

 

The fan belt can flex but straight would be better for long life. You may be able to take the alternator mount off the block and grind 1/8" one side and add washers on the other to in effect shim it back. There were many different mounts and I don't know what type you have. When done, the metal adjustment strap should go on the front of the alternator case not behind like you have, and it's upside down.

[Negative Ghostrider]

1 hour ago, datzenmike said:

 

Plugs changed often. The wires were generally the same.

 

 

The fan belt can flex but straight would be better for long life. You may be able to take the alternator mount off the block and grind 1/8" one side and add washers on the other to in effect shim it back. There were many different mounts and I don't know what type you have. When done, the metal adjustment strap should go on the front of the alternator case not behind like you have, and it's upside down.

 

I had to flip the bracket to make it fit. When it was normal orientation it was hitting the top of the alternator body before the hole and the slot lined up. Works great flipped over. I can put a couple bends in it if I need to fit it to the front I guess. It seems solid as is though.

[datzenmike]

I've done the same for about the same reason.

[thisismatt]

3 hours ago, Negative Ghostrider said:

I have the alternator fitted. It's a model R111307A from autozone, which is a 60A that fits various Nissans including the 720 and I think a 200 or 240. I ordered it based on a thread in here that I read but can't seem to find now which said it was drop-in with a v belt from the associated car. Anyhow, I was able to get it in and sitting pretty well by just flipping the upper bracket over. The belt is just a hair too short or else the top of the alt will rub on the radiator hose. That's easily remedied. The more pressing concern is that the pulley sits about 1/8" further forward than the crank and cam pulleys. Is that enough to cause an issue? 

 

Did you check if there is a spacer or washer on the alt shaft that you could remove or cut down?

[Negative Ghostrider]

1 hour ago, thisismatt said:

 

Did you check if there is a spacer or washer on the alt shaft that you could remove or cut down?

 

You mean between the pulley and the blades? No. I did not. It doesn't look like there's even 1/8 gap between them.

 

I feel like it's probably going to be ok. The truck isn't going to be a daily. If I see excessive or uneven wear on the belt after a short time I will just shave down the bracket a hair. 

[thisismatt]

Or between the fan & alternator body.

[Negative Ghostrider]

21 hours ago, datzenmike said:

I've done the same for about the same reason.

In the interest of experimentation I made jumpers to make sure everything works before I cut up my regulator. I have a matching harness on the way that I can use for a more permanent solution if everything checks out. 

 

Regarding the choke heater relay, the truck already had the "weber" with the auto choke on it and a number of wires were already disconnected. Solid blue and both of the Blue with white are off, and the White with blue had been extended out to the auto choke. Didn't have any battery draining issues previously. Am I good to go with this configuration? Thanks! 

[datzenmike]

If you made jumpers keep that and save the regulator.

 

The choke heater relay needs to be unplugged. This jumper on the plug leaves the coil in the relay ON even with the ignition OFF. Takes about 3 days to run the battery down but it will.