RPM Gauge Defender Puma (W terminal) on alternator

[retromatic]

Hi guys,

If anyone wants to fit an RPM Gauge to your Defender Puma (2.4 in my case) but I am betting it's the same for 2.2. Here is what I did.

I am fitting an EMS3 gauge which has RPM input also, so I figured why not use it.

Now with diesels you don't have a true straight forward way of detecting RPM, Unless you pick this up from a crank sensor I guess. The only way is to pickup from the rotational speed of the alternator. This is your only option, and I don't know anyone else doing it via crank sensor.

Apparently most of the older alternators have a W terminal on the back of them for the RPM Gauge. But not the Defender Puma 2.4 alternator, which is actually a Bosch alternator.

So to add this to any alternator you need to tap into one of the windings. Fortunately the Defender alternator makes this very, very, easy.

1. Disconnect you vehicle battery/batteries.
2. Take the positive off the back of alternator
3. Remove the plug fitting with two wires
4. Remove the screws that hold the black plastic cover and take cover off.
5. You will notice a black plastic device (regulator) BTW when an alternator starts to fail to charge 90% of time this just needs to be replaced.
6. Take eyelet terminal (see photos) and fly wire fit it behind the screw for the alternator winding.

Then you have yourself a W wire terminal for an RPM Gauge. In my case an EMS3, this gauge can then be calibrated to match the exact ECU reading of RPM that is taken from the crank sensor.

Hope it helps alot of people because I couldn't find the info anywhere on the interwebs.

All the best,

Damo

https://uploads.tapatalk-cdn.com/20210327/bc436416de815e76ac0403ca152a7799.jpghttps://uploads.tapatalk-cdn.com/20210327/b00d922f219ed8a1f72dd87f0888cc4e.jpghttps://uploads.tapatalk-cdn.com/20210327/9dccfb103bdd1633082bcf79692b5643.jpghttps://uploads.tapatalk-cdn.com/20210327/131364a9908f48ae01be48d61318c258.jpghttps://uploads.tapatalk-cdn.com/20210327/b41fb813b55edba3f20be5a450a4589c.jpghttps://uploads.tapatalk-cdn.com/20210327/f88f94f601dd5e6729111d7874c3a8e1.jpghttps://uploads.tapatalk-cdn.com/20210327/3eca16f3bb7144b5f3df7761ab44bbd4.jpghttps://uploads.tapatalk-cdn.com/20210327/55d6d6998052954a00ae918bb0a1cd64.jpghttps://uploads.tapatalk-cdn.com/20210327/d6baf77d96937a43c6ae69b04d49348b.jpg

[p38arover]

Doesn’t the Defender have a tachometer as standard equipment?

[Tombie]

Why would you bother when the dash has one standard?

Lot of effort for no gain

[W&KO]

I always wonder why the need to fit a Tacho to a defender, well for the models that don’t have one standard.......

Brought my first defender back in 2000 amd was driving 110’s since 1990 and never once thought geez, wish I had a tacho

[Toxic_Avenger]

Maybe he means the full habib-spec monsta tach with shift light? [bigwhistle]

[W&KO]

Maybe he means the full habib-spec monsta tach with shift light? [bigwhistle]

Even in my stay racing days (street class) I still didn’t worry about a tacho.....

[W&KO]

Maybe he means the full habib-spec monsta tach with shift light? [bigwhistle]

Even in my stay racing days (street class) I still didn’t worry about a tacho.....

[retromatic]

I wrote this "I am fitting an EMS3 gauge which has RPM input also, so I figured why not use it."

The Madman EMS3 gauge is a 6 in one, gauge, with ability to set alarms for each input, logging etc.. I purchased it mainly for the EGT alarm and monitoring EGT temps but it has so many other inputs. RPM being one of them.

I only did this mod to alternator so that RPM can also be logged on the Madman EMS3.

I really posted the info as a reference for anyone that may need to do the same thing.

BTW the "Habibi" comments are racist I'm not arabic but I can imagine that Arabic people might find that offensive. Please be sensitive to others. Usually I would just ignore these types of comments but the government's currently running a TV commercial about bullying and racism and to call it out and not ignore it. So I'm just highlighting that those comments are not required.

I wish you all well and hope that someone may find this info helpful.

All the best

Namaste.

Damo
https://uploads.tapatalk-cdn.com/20210328/2cf7924dc2a687ba4270e6aa665f2080.jpg

[Tombie]

It’s not racist - it’s profiling. [emoji41] like the show “Housos”


I know it has it, but the effort isn’t really worth the gain. I have had Madman units for years and the superfluous features were ignored.

But power to you for the write up and effort.

[p38arover]

I must admit I've never heard it called an RPM gauge before, only tachometer.

[Toxic_Avenger]

Right-o then.
I'll solemnly clutch my bucket hat to my VB singlet, and give a wholehearted Aussie bogan apology.

I must admit though, a good monster tach is also equally at home on a sex-spec mitsubishi lancer circa 1998, or on VT commodores doing "mainy's" all night, and driven by blokes who call themselves Dazza.
It just so happened that I did know a few gents of middle eastern origination with such tachometers, and to their credit they were always handing me a losing timeslip on the 1/4mile.

[retromatic]

Thanks guys,

I thought it was too good info not too share.

This is my first 4x4 and first diesel so I'm still learning and like to help others if I can.

All the best,

Damo

[p38arover]

No, it’s good info. I’ve looked at it in the past as a way to fit old cars with a tacho.

[W&KO]

Thanks guys,

I thought it was too good info not too share.

This is my first 4x4 and first diesel so I'm still learning and like to help others if I can.

All the best,

Damo

Agree, good info to share for those wanting to fit.

[retromatic]

Here is a better photo of the alternator regulator and it's terminals. It's the PS terminal you are after for RPM
Hi guys,

If anyone wants to fit an RPM Gauge to your Defender Puma (2.4 in my case) but I am betting it's the same for 2.2. Here is what I did.

I am fitting an EMS3 gauge which has RPM input also, so I figured why not use it.

Now with diesels you don't have a true straight forward way of detecting RPM, Unless you pick this up from a crank sensor I guess. The only way is to pickup from the rotational speed of the alternator. This is your only option, and I don't know anyone else doing it via crank sensor.

Apparently most of the older alternators have a W terminal on the back of them for the RPM Gauge. But not the Defender Puma 2.4 alternator, which is actually a Bosch alternator.

So to add this to any alternator you need to tap into one of the windings. Fortunately the Defender alternator makes this very, very, easy.

1. Disconnect you vehicle battery/batteries.
2. Take the positive off the back of alternator
3. Remove the plug fitting with two wires
4. Remove the screws that hold the black plastic cover and take cover off.
5. You will notice a black plastic device (regulator) BTW when an alternator starts to fail to charge 90% of time this just needs to be replaced.
6. Take eyelet terminal (see photos) and fly wire fit it behind the screw for the alternator winding.

Then you have yourself a W wire terminal for an RPM Gauge. In my case an EMS3, this gauge can then be calibrated to match the exact ECU reading of RPM that is taken from the crank sensor.

Hope it helps alot of people because I couldn't find the info anywhere on the interwebs.

All the best,

Damo

https://uploads.tapatalk-cdn.com/20210327/bc436416de815e76ac0403ca152a7799.jpghttps://uploads.tapatalk-cdn.com/20210327/b00d922f219ed8a1f72dd87f0888cc4e.jpghttps://uploads.tapatalk-cdn.com/20210327/9dccfb103bdd1633082bcf79692b5643.jpghttps://uploads.tapatalk-cdn.com/20210327/131364a9908f48ae01be48d61318c258.jpghttps://uploads.tapatalk-cdn.com/20210327/b41fb813b55edba3f20be5a450a4589c.jpghttps://uploads.tapatalk-cdn.com/20210327/f88f94f601dd5e6729111d7874c3a8e1.jpghttps://uploads.tapatalk-cdn.com/20210327/3eca16f3bb7144b5f3df7761ab44bbd4.jpghttps://uploads.tapatalk-cdn.com/20210327/55d6d6998052954a00ae918bb0a1cd64.jpghttps://uploads.tapatalk-cdn.com/20210327/d6baf77d96937a43c6ae69b04d49348b.jpghttps://uploads.tapatalk-cdn.com/20210510/22f6b840e2a76d56ef78a49e29d5d095.jpg
https://uploads.tapatalk-cdn.com/20210510/57530f871d3334cbc7f11901db4c0646.jpg

[ramblingboy42]

Right-o then.
I'll solemnly clutch my bucket hat to my VB singlet, and give a wholehearted Aussie bogan apology.

I must admit though, a good monster tach is also equally at home on a sex-spec mitsubishi lancer circa 1998, or on VT commodores doing "mainy's" all night, and driven by blokes who call themselves Dazza.
It just so happened that I did know a few gents of middle eastern origination with such tachometers, and to their credit they were always handing me a losing timeslip on the 1/4mile.

oh I get it , put a big mutha tacho in it and it goes like hell.

[retromatic]

NO, more like install a Madman EMS3 gauge and set the RPM alarm so no one over revs it.

If your buying a defender or any 4x4 for that matter to go fast, hmmm, I think there is something wrong. Would be like taking a cardboard box throwing it in the air and expecting it to fly like a paper plane.
oh I get it , put a big mutha tacho in it and it goes like hell.

[ramblingboy42]

ya got a flat top out of that one didn't you[bigrolf][bigrolf][bigrolf][bigrolf]

straight over your head