Replacement alternator

Please tell us about your DIY projects, tips and tricks
User avatar
ChristoSlang
Patrolman
Patrolman
Posts: 870
Joined: 07 Apr 2009 16:54
Full Name: Christo van Rensburg
Nickname: ChristoSlang
Home Town: Pretoria, ZA
Current 4x4: Nissan 4.2 GL Patrol
Home Language: Afrikaans
Location: Garsfontein, Pretoria
Has thanked: 5 times
Been thanked: 71 times

Re: Replacement alternator

Post by ChristoSlang » 12 Jul 2011 18:16

The problem with increasing the alternator output to compensate for the voltage loss in the National Luna system's solenoid is that the deep cycle battery ideally wants to charge at 14.5 Volts or so, but a crank battery does not like going this high. Now calculating in the voltage loss means that you have to bump up the alternator's voltage to 15.5V. But the crank battery gets it's charge directly from the alternator, and will thus sustain damage at these high voltages.
Peter, you're on the right track here... 1V between the alternator and the battery is a lot! You're gonna lose some more voltage between the battery and the fridge, so you'll definitely be in trouble from the outset. I added an additional cable in parallel between my second battery and the alternator to counter this voltage drop and improve current transfer.

So, before you replace alternators, make sure that your cabling is up to scratch. If there's a notable (I'd say anything more than about 0.5V?) between the alternator and the battery terminals, fix that first. Those thick earth & positive cables are crimped to connectors that are screwed onto an exposed bits of bodywork & engine. Crimping is a good way to ensure good current transfer, but needs to be checked every so often on vehicles like our that are partly submerged every so often. A badly crimped or rusted connection will merely convert your alternator's charging current into heat (and even sparks!). The same for for the bolts that fasten the connectors - make sure they are tight. But loosen them first and check that the area underneath is rust-free before you tighten them up :thumbup:

I'd be very careful of tampering with an alternator's voltage regulator to raise it's output voltage. It may be good for your deep-cycle battery, but it is VERY BAD for every single other electrical component in your car that does not have its own voltage regulator. All in car electronics state explicitly that they are meant to be fed between 13.8V -14.2V, no more! If your deep-cycle battery wants a higher charge voltage more, change it to one that doesn't want to make its own rules at the cost of all other electrical components! :mytwocents:
Christo have you experienced any problems since you did the alternator replacement with "over charging"??
You can safely "tamper" with the current output of your alternator (by purchasing a higher output alternator!). To charge a battery faster, you increase the available charge current, not the voltage. Alternators are self-limiting (via their voltage regulator circuitry), meaning that a 145A alternator will not supply its full 145A of current unless its actually required. If the current requirement drops, it will drop its current output accordingly. So... there is no risk of "overcharging" batteries when installing a larger alternator.

Remember, the initial alternator was selected by the manufacturer to produce enough current to handle the continual current draw (engine management components, ignition coil, lights, interior fan, air-con clutch and fan, radio & amps, glow plugs, 2-way radio, etc.) whilst still having sufficient excess capacity to re-charge your battery. When you have two batteries, you halve the available current for recharging, so it will now require a trip twice as far to recharge them both! Replacing it with a larger alternator creates more excess current, and you're effectively back where you were with a single battery.
Christo.....If I used my existing pulley, how will that affect the charging ?? Will the revs not need to be a lot higher to get the charge to kick up over the 12 volt earth voltage for the dash light to go off?? :think: :think:
Cedricster, the original pulley won't fit due to the fact that the Delco is an American (SAE spec) alternator and the Hitachi uses a DIN spec pulley. Unless you find someone who can machine it for you? Make sure that the ratio between the circumference of the first drive pulley (on the engine block) and the alternator's pulley is more or less 2:1 so that you do not over-rev the alternator. You'll see that the Delco is specced for a continuous 10k RPM with bursts of 12k RPM. On our diesels we may use an even smaller pulley than the one they come with, methinks. Chat to Alan, he easily found me a pulley to go with the alternator....
Christo (the snake man)
1998 4.2 GL Patrol (Chuck Norris)
2007 350Z twin-turbo coupe (Batmobile)
Image

User avatar
Aries66
Senior Member
Senior Member
Posts: 311
Joined: 08 Apr 2009 12:19
Full Name: Louis Naude
Nickname: Aries66
Home Town: Pretoria, Sinoville
Current 4x4: 2000 Patrol 4.2 TD
Home Language: Afrikaans
Location: Pretoria, Sinoville
Been thanked: 2 times

Re: Replacement alternator

Post by Aries66 » 26 Jan 2013 20:14

Na 'n lang gesukel met my alternator, het ek besluit genoeg is genoeg. Die ding het nooit konstant krag gelewer nie. as ek gelukig was het die Madman se alarm nie afgegaan nie, het later maar die waarskuwing afgestel tot 10v. Die spanning het selde 13v beruik.

Na ek weer die artikel raak gelees het, het ek biekie ondersoek ingestel wat beskikbaar was en toe op die Delco 28SI besluit wat glo ek nogal n bielie is. Die ou een was maar n 60A model. Delco is 'n 160A met en wat hom ook nogal lekker maak hy het die nuwe "Battery sence" opsie in om voorsiening te maak vir enige spannings verlies wat daar mag wees tussen die battery en altenator. Met die sensor geaktiveer sal die spanning opgevat word tot 14.5v. Idiaal vir "deep cycle" batterye.

Ek het baie van Christo se voorstelle gebruik.(DANKIE CHRISTO). Al wat nodig was om die ombouing te doen was, 'n hegstuk om van die oorspronklike hegpunte na die nuwe
aansienlike grooter hulsel van die Delco en 'n biekie langer v-belt (477) en so biekie vyl aan die oorspronklike verstellings arm se gate.
IMG-20130126-00126.jpg
IMG-20130126-00126.jpg (98.3 KiB) Viewed 1444 times
So halfpad gesukel om als te laat pas .
IMG-20130126-00127.jpg
IMG-20130126-00127.jpg (83.1 KiB) Viewed 1444 times
Die nodige bedrading, inplek sal later die " sense" drade koppel.
IMG-20130126-00128.jpg
IMG-20130126-00128.jpg (121.8 KiB) Viewed 1444 times
Als in plek,
IMG-20130126-00129.jpg
IMG-20130126-00129.jpg (116.96 KiB) Viewed 1444 times
Wat n mooi syfers om te sien, die battery gaan nou lekker volgelaai word.

IMG-20130126-00133.jpg
IMG-20130126-00133.jpg (113.89 KiB) Viewed 1444 times
14v teen luier spoed.

User avatar
ChristoSlang
Patrolman
Patrolman
Posts: 870
Joined: 07 Apr 2009 16:54
Full Name: Christo van Rensburg
Nickname: ChristoSlang
Home Town: Pretoria, ZA
Current 4x4: Nissan 4.2 GL Patrol
Home Language: Afrikaans
Location: Garsfontein, Pretoria
Has thanked: 5 times
Been thanked: 71 times

Re: Replacement alternator

Post by ChristoSlang » 26 Jan 2013 22:41

Bly jy het reg gekom! My Delco is nog steeds 'n staatmaker :thumbup:

Daai Patrollie van jou idle nogal erg stadig - ek neem aan jy het die alternator se exciter draad ook gekoppel om 14V teen daai lae revolusies te sien?
Christo (the snake man)
1998 4.2 GL Patrol (Chuck Norris)
2007 350Z twin-turbo coupe (Batmobile)
Image

User avatar
Aries66
Senior Member
Senior Member
Posts: 311
Joined: 08 Apr 2009 12:19
Full Name: Louis Naude
Nickname: Aries66
Home Town: Pretoria, Sinoville
Current 4x4: 2000 Patrol 4.2 TD
Home Language: Afrikaans
Location: Pretoria, Sinoville
Been thanked: 2 times

Re: Replacement alternator

Post by Aries66 » 27 Jan 2013 06:57

Christo, nee hy het nie exciter, al wat ek heidig gekoppel het is die positief, negatief en dan die laai liggie.
Hy idle altyd so laag, selfs my vorige een sonder Turbo het dieselfde idle spoed gehad. Ek weet nou nie of dit net my verbeelding is nie, maar die motor klink ook sommer stiller nou.

Weereens dankie vir jou goeie artikel dit het baie gehelp. :salute: :salute: :salute:

Iets oor die 28SI : http://www.delcoremy.com/Alternator-Mod ... nator.aspx

User avatar
davejones
Senior Member
Senior Member
Posts: 450
Joined: 25 Mar 2010 13:52
Full Name: David Jones
Nickname: David
Home Town: Lagos, Nigeria
Current 4x4: 1998 Nissan Patrol 4.2D GL
Home Language: English
Has thanked: 1 time
Been thanked: 5 times

Re: Replacement alternator

Post by davejones » 24 Mar 2013 10:04

also have to do my alternator... patrol a bit of a money drain at the moment :doh: the ups and the downs i guess :biggrin:

will call nissan tomorrow, but what is the damage for a nissan replacement? I'm unable to do the job myself if it comes to making up new brackets etc, most likley will have it done at a mechanic (Menlyn Brake and Clutch) or SAC who seem more keen on working with original parts and limited maak-n-plan initiative.....
1998 Nissan Patrol GL (GU / Y61 - TD42, with turbo)
An ox, but with balls !!!

User avatar
Jorrie
Patrolman 1000+
Patrolman 1000+
Posts: 2393
Joined: 21 Jun 2011 18:55
Full Name: Jacobus Jordaan
Nickname: Jorrie
Home Town: Pretoria
Current 4x4: 1998 Nissan Patrol 4500 GRX, 2011 Zook
Home Language: English/Afrikaans
Location: Pretoria
Has thanked: 109 times
Been thanked: 88 times

Re: Replacement alternator

Post by Jorrie » 25 Mar 2013 06:16

The OEM will quote astronomical prices - in excess of R16000 and up to R18000.
Search this forum on the subject before you buy!!!!. Some members replaced tjeor altenators for less than R2000. Good luck.
Jorrie
4500 GRX
Jimny

User avatar
davejones
Senior Member
Senior Member
Posts: 450
Joined: 25 Mar 2010 13:52
Full Name: David Jones
Nickname: David
Home Town: Lagos, Nigeria
Current 4x4: 1998 Nissan Patrol 4.2D GL
Home Language: English
Has thanked: 1 time
Been thanked: 5 times

Re: Replacement alternator

Post by davejones » 25 Mar 2013 09:24

Just spoke to Nissan - they quoted me R2747.90 for the replacement alternator.

Part number 231007T40A

http://www.autopartoo.com/oem/nissan/231007t40a.html

Voltage [V]14
Vehicle Main Current
Alternator Charge Current [A]60
Used part return not required
Position / Degree0°
Belt Pulley ? [mm]84
Supplementary Article/Supplementary Info
Pulleys
Diameter [mm]120
Cooling Type

And they can have it in the store tomorrow morning....

Price does seem VERY low, am i missing something?

:think:
1998 Nissan Patrol GL (GU / Y61 - TD42, with turbo)
An ox, but with balls !!!

User avatar
Jorrie
Patrolman 1000+
Patrolman 1000+
Posts: 2393
Joined: 21 Jun 2011 18:55
Full Name: Jacobus Jordaan
Nickname: Jorrie
Home Town: Pretoria
Current 4x4: 1998 Nissan Patrol 4500 GRX, 2011 Zook
Home Language: English/Afrikaans
Location: Pretoria
Has thanked: 109 times
Been thanked: 88 times

Re: Replacement alternator

Post by Jorrie » 25 Mar 2013 10:36

Ask some other dealers for quotes. That price seems too good to be true from the OEM.
If it is a genuine new Nissan altenator with the correct specs - then take it.
Jorrie
4500 GRX
Jimny

User avatar
davejones
Senior Member
Senior Member
Posts: 450
Joined: 25 Mar 2010 13:52
Full Name: David Jones
Nickname: David
Home Town: Lagos, Nigeria
Current 4x4: 1998 Nissan Patrol 4.2D GL
Home Language: English
Has thanked: 1 time
Been thanked: 5 times

Re: Replacement alternator

Post by davejones » 25 Mar 2013 11:54

I've phoned around and get the same price quoted....

could there really be a patrol part that is reasonably priced....?! :lol:
1998 Nissan Patrol GL (GU / Y61 - TD42, with turbo)
An ox, but with balls !!!

User avatar
Chris Skinner
Patrolman
Patrolman
Posts: 947
Joined: 26 Nov 2009 12:58
Full Name: Chris Skinner
Nickname: Chris
Home Town: Centurion
Current 4x4: Nissan Patrol 4,8 GRX 2005
Home Language: English
Has thanked: 10 times
Been thanked: 56 times

Re: Replacement alternator

Post by Chris Skinner » 25 Mar 2013 13:32

60 Amp - sounds a bit light!

Post Reply

Return to “21. DIY Projects”

Who is online

Users browsing this forum: No registered users and 1 guest