TDI Ranger Build

Ranch

Well-known member
Joined
Sep 28, 2016
Location
midwest
TDI
ALH
I have an older Cummins that originally came with an air starter, and the 'fire in the box' cold starting aid.. Hold a button down to fill the little compartment with raw fuel, and then hold another down to light it, simple heating element.
By the time I got it, it had already been swapped back to 24v starter, and I really don't need to fire it up when cold. It's a summer machine for me.
I wish the ol gal still had the air starter, that will most definitely wake the chickens! And totally piss off the neighbors ;)
 

ben2go

Well-known member
Joined
Aug 19, 2014
Location
Gone
TDI
none
I have an older Cummins that originally came with an air starter, and the 'fire in the box' cold starting aid.. Hold a button down to fill the little compartment with raw fuel, and then hold another down to light it, simple heating element.
By the time I got it, it had already been swapped back to 24v starter, and I really don't need to fire it up when cold. It's a summer machine for me.
I wish the ol gal still had the air starter, that will most definitely wake the chickens! And totally piss off the neighbors ;)
Those are some mean sounding devices. We had an old Mack day cab with an air starter. I'd park it where people are standing around, and hit the switch. Some would jump. Others would run.:D
 

greengeeker

Vendor
Joined
Feb 8, 2006
Location
Cambridge, MN
TDI
2002 Jetta GLS
Have to ask...How far did you tow the trailer with the wagon on it? How does the Ranger manage to stop that load?
For that tow it wasn't very far but I have towed another B5 wagon over an hour away. Towed it just fine. Key to the towing performance are two things 1) the airbags which help significantly with stability while towing 2) trailer brake controller with trailer brakes in tip top shape. I wouldn't be comfortable towing something like these two items without #2.
 

greengeeker

Vendor
Joined
Feb 8, 2006
Location
Cambridge, MN
TDI
2002 Jetta GLS
I seem to be going through alternators and I could use some help to figure out why. I've been throwing used alternators at it for a while and finally decided to bite the bullet and buy a new (reman'd) Bosch unit. Since I had a bit more money into this alternator I figured I better spend a little more time investigating what the hell is going on. I did a log with the Ranger and then did the same exact drive in my 2002 Jetta. Both vehicles have ~1 year old batteries. The Jetta's alternator is original (311k miles) and the Ranger's is brand new...first miles were driven during these logs.

In case you were interested, here was the drive:
1) Lights on, radio on
2) Pull out of driveway, get into 5th and drive for 4 miles (~60 mph)
3) Park and let engine idle, turn off headlights
4) Turn lights back on, turn back around and head back home.



A couple of observations/comments (please add others you may notice)
1. You can see that the low and high coolant glow plugs were activated at the start of the log on my Jetta. Ranger doesn't have coolant glow plugs. I don't believe combustion glow plugs operated for either vehicle during the logs (checked before I started logging but didn't log those MBs).
2. During steady-state cruising with the GPs off you can see the Jetta's duty cycle (DC) hovered around 25% while the Ranger was in the 60-65% range.
3. I did do a throttle blip on the Jetta (towards the end of the idle period) to make sure the DC dropped with revs. I forgot to do this with the Ranger but I'm not sure I saw the same behavior just looking at the MB without logging.
4. I should note that the battery on the Ranger was somewhat low just prior to logging (remember...bad alternator). Could have something to do with the abnormally high DC?

Here is the same log but with battery voltage added.



Observations/comments:
5. You'll notice that the Jetta's cruising voltage is 14.2 while the Ranger is 14.1.
6. You'll also notice both seem to want to increase voltage during idle. Jetta is able to achieve the very typical 14.4V while the Ranger is barely able to eclipse 14.2V.
7. Oddly, the cruising voltage for the Ranger dropped the longer I drove it. The opposite was true for the Jetta.

So I'm trying to rack my brains why the Ranger has a higher duty cycle. the only additional loads would be the lift pump. Could that possibly be drawing so much power that it is the problem? I'd be surprised because the Ranger originally came with a 95A alternator (120A alternator on both the Ranger and Jetta).

Knowing how high the DC is with no additional loads, I'm pretty sure when I hook up my trailer with its electric brakes and lights I've got to be pushing the alternator even harder...possibly to the point of failure.

I did measure resistance from my negative battery terminal to the accessory mounting bracket on the engine at 0.2ohms. Same as other places on my block and similar to what I measure on VWs.

Thoughts?

TIA!
 
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dremd

Veteran Member
Joined
May 31, 2007
Location
South Louisiana
TDI
06 sprinter. 03 jetta wagon premium with 6 speed ALH swap, 14 JSW
My thought would be to fire up the ranger, engage every load you have and measure voltage drop between the battery and alternator, both positive and negative as well as voltage drop on the ground side between the battery and Chasis and Chasis iand alternator. If you don’t see anything look for frayed wires, after that try and see how hot the alternator in the Ranger is running (temperature wise) vs the Jetta.

All based on opinions with no real data.
 

ben2go

Well-known member
Joined
Aug 19, 2014
Location
Gone
TDI
none
I can only add to what others have said. Check and clean gounds. I know they may look good but I have found rust and corrosion under the connections. Is there a good ground between the engine and chassis? Is it close to the alternator? I have run grounds directly from the alternator mounting bolt to the chassis ground where the battery ground mounts to the chassis. Do you have a ground between the cab and chassis or cab and engine? My '01 Ranger has one off the back of the head to the cab.
 

A-man930

Veteran Member
Joined
Jul 29, 2014
Location
St. Louis
TDI
Planning Stages: ALH Jeep MJ
My thought would be to fire up the ranger, engage every load you have and measure voltage drop between the battery and alternator, both positive and negative as well as voltage drop on the ground side between the battery and Chasis and Chasis iand alternator.
+1
The ohmmeter reading means virtually nothing here; two strands of copper left in a cable will carry the current the meter puts out just fine and not look much different than a good cable.
With as many current-hungry things on as is possible, observe the voltage dropped between:
-the negative post and the case of the alternator
-the positive post and the output stud on the alternator
you should see very little voltage drop during either test.
And yes, a partially failed battery will overwork an alternator.
good luck!
 

Hasenwerk

Vendor , w/Business number
Joined
Nov 28, 2003
Location
Quesnel, BC
TDI
1982 Cabriolet (BEW|VNT17|Stage4), 1989 VW TriStar Syncro soon-to-be CR TDI (CBEA), 2001 Ford Ranger Edge 4x4 (ALH|VNT17|R520|Stage4)
Do you have the correct "exciter" circuit in there? Normally, in a Volkswagen, when you turn the key ON, but the engine isn't running the alternator light comes on. This is part of the exciter circuit. One side of this light goes to the 12V switched circuit and the other side goes to the D+ terminal on the alternator. The light goes on because the alternator isn't making energy and it is essentially a ground circuit at that point. When the engine is on, the alternator makes energy and D+ goes high and turns the light off. D+ is looking for a reference voltage - so if this isn't connected in your Ranger then it leads to a confused state on the alternator and charging issues. To make the circuit is easy, just a small light bulb or 1K 'ish' resistor between 12V switched and the D+ terminal.
 

greengeeker

Vendor
Joined
Feb 8, 2006
Location
Cambridge, MN
TDI
2002 Jetta GLS
Thanks for the input guys. Very good ideas.

I'll do a couple checks to rule things out:
1) Verify my exciter circuit is sending 12v to D+ (it was when I checked duing the swap)
2) Very easy to swap batteries
3) Will try and load the alternator as much as possible and measure voltage as A-man described. I've often thought this would be a good way to determine if your starter lead and ground are providing resistance to high current flows. Guess I'll need to upgrade my multimeter to one that has a MAX function. :)
4) above test will indicate if connections are needing to be cleaned.

Thanks again.
 

A-man930

Veteran Member
Joined
Jul 29, 2014
Location
St. Louis
TDI
Planning Stages: ALH Jeep MJ
I've often thought this would be a good way to determine if your starter lead and ground are providing resistance to high current flows. Guess I'll need to upgrade my multimeter to one that has a MAX function.
100% correct and yes min/max is a necessity when flying solo! This method is far and away the most practical and accurate way to check any automotive circuit for unwanted/excessive resistance. Again, good luck! :D
 
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greengeeker

Vendor
Joined
Feb 8, 2006
Location
Cambridge, MN
TDI
2002 Jetta GLS
100% correct and yes min/max is a necessity when flying solo! This method is far and away the most practical and accurate way to check any automotive circuit for unwanted/excessive resistance. Again, good luck! :D
What should one see for max voltage drop for either the starter circuit or the alternator circuit? <<1V?
 

A-man930

Veteran Member
Joined
Jul 29, 2014
Location
St. Louis
TDI
Planning Stages: ALH Jeep MJ
Depends on who you ask but ideally under 500 or 600mV. Considering the problem you're having I would expect it to be quite obvious if there's a problem here (over a volt maybe?)
 

greengeeker

Vendor
Joined
Feb 8, 2006
Location
Cambridge, MN
TDI
2002 Jetta GLS
Apologies I seem to be having some issues with the picture server tonight...I'm not consistently seeing the icon which allows me to copy the medium-sized image.

Well I might have stumbled onto something tonight.

I did a quick test at idle turning a couple loads ON. You'll notice that the duty cycle goes DOWN with each subsequent load APPLIED.



Here is the same graph but I'm showing the inverse of what VCDS is showing....seems to make more sense.



The last thing I did was rev the truck with no loads applied. You'll notice that the duty cycle INCREASES as the alternator speed increases...opposite of what you would expect.



So given the behavior I'm seeing I wanted to compare the original logs but the inverse of the Ranger's:



Looks a lot more reasonable. 35% duty cycle compared to the 25% of the Jetta.

At this point I'm assuming that I have the two wires to the alternator swapped. Will need to double check those tomorrow.
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
the field wire is just a sense wire for the computer,
meaning if they're hooked up backwards then the alt isn't getting excited by the 'battery lamp' as I doubt they'd add provision to put current to the alternator field directly from the computer.

if the alt isn't getting an excitation signal it probably won't self excite until you rev the motor a good bit above idle, dunno about these specific alternators but I know a ford 3g alt (pretty modern) with a '97 explorer accy drive (from memory a pretty close ratio match to the ALH stuff) needs about 2700 RPM before it'll self excite.

also, the 'battery lamp' will have increasing voltage across it with decreasing load on the alternator (battery light on the dash turns off when you turn on the headlights or what have you)

this is all for if the two small wires are reversed
 

greengeeker

Vendor
Joined
Feb 8, 2006
Location
Cambridge, MN
TDI
2002 Jetta GLS
Fair enough. I will say that the new alternator immediately jumps to >14V when I start the truck. I'll have to double check that the battery light functions properly which I think it does : turns off as soon the truck starts and illuminates when the voltage dips below a certain threshold. Had the pleasure of eyeing that evil little gauge recently. Fun fact. Did you know a TDI will run on at least 7V? I don't know how low it really will go because that's where a scangauge shuts down. :eek:
 

DoesItDiesel

New member
Joined
Feb 25, 2018
Location
Southwestern Ohio
TDI
none (transplant coming in 2019)
Thank you for posting your experiences during this project, greengeeker. I intend to perform a similar swap and this thread has already proven very informative.
 

nitro_junkie001

Well-known member
Joined
Nov 19, 2012
Location
Tampa Fl.
TDI
2000 TDI Golf 5 speed . 2002 TDI. Jetta Wagon 5 speed - Sold .2003 TDI golf Auto,. SOLD .2002 Tdi Jetta 5 speed SOLD
♤ ^^^ what he said.
 

Nozzleman

Veteran Member
Joined
May 30, 2014
Location
About 15 miles from Venus
TDI
2002 Ford Ranger ALH
I have seen several clean unspliced battery cables over the years that looked beautiful on the outside that wouldn't start the vehicle.


Another thought is that as I recall you are running an electric fuel pump that the Jetta does not have.
 

greengeeker

Vendor
Joined
Feb 8, 2006
Location
Cambridge, MN
TDI
2002 Jetta GLS
Last four tanks: (miles/gal: MPG)
715.4/18.187 = 39.3
710.8/18.035 = 39.4
977.2/24.375 = 40.1
753.1/18.244 = 41.3
New goal is to get an 800 mile tank on this bad boy. :)
Minor update on the truck: new front brakes and bearings.

New MPG record :):
755.1/18.185 = 41.5

(no I did not achieve this MPG towing this around :D)
 

Kriesel

Veteran Member
Joined
Feb 22, 2009
Location
Afton, MN
TDI
2006 Jetta TDI
Minor update on the truck: new front brakes and bearings.
New MPG record :):
755.1/18.185 = 41.5
(no I did not achieve this MPG towing this around :D)
You should shoot for some crazy number and try to make it super aerodynamic for like a month, just to see what it can do:
 
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