-
Add "W" terminal wire to Bosch/Valeo serp-belt TDI alternator
by
Syncroincity
on 08 May, 2014 00:47
-
I have a nice fat 120 amp alternator out of a TDI attached to my AAZ install, the problem was; no W terminal to run the tach. I used a MKII "2.22" diesel tach fitted into my original Vanagon instrument cluster. I used this alternator to provide; 1. Clutched over-run pulley to take the strain off the AAZ crank nose with the serpentine setup, and 2. AMPS, baby.
Plastic cover and easily detachable brush pack... remove a few screws and you're looking at the stator windings. Check your brush condition while you're in here.
Photos are representative; not my alternator.
On these alts, the winding wires terminate in these little loops that mechanically crimp and lock them in. The outermost ones are what you need, one that does not connect to a diode. Red arrows in the pic below. (You can see the diodes below the other connections, round, fairly obvious.) Find one with a little space between the winding wires, or use a screwdriver blade to spread one open a bit. Clean with a wire brush to expose good bare metal, and loop a wire end into it and re-crimp the winding ends. Solder the wire. I had to use a butane torch, my soldering iron wouldn't quite heat everything up enough.
In the Vanagon, connect that wire to the solid blue wire in your junction box if present.
Result: tachometer reading! I have no way to verify the RPMs, but it seems close to where it should be, a bit high maybe... shows about 900 at idle. The serpentine pulley is slightly smaller than the v-belt pulley. I'll have to go in and find the adjustment pot on the tach one of these days.
-
#1
by
theman53
on 08 May, 2014 07:28
-
good deal. It just picks up off one of the stator wires for the w signal then?
-
#2
by
GEE-BEE
on 08 May, 2014 10:29
-
I found a local shop that has new and ohc units with the W terminal
They offer powdercoated housings also for 45.00 in any color
I have a 90 and 120 amp core
GB
-
#3
by
vanbcguy
on 08 May, 2014 10:39
-
There is an AAZ 120A alternator with a W terminal in the wild... I put one on my build. :-D But this is great for anyone that has a non-W alternator already!
Sent from my HTC One XL using Tapatalk
-
#4
by
Syncroincity
on 09 May, 2014 00:13
-
good deal. It just picks up off one of the stator wires for the w signal then?
Exactly, and it doesn't matter which one you pick (there are six, 3 pairs), as long as you tap it before the diodes.
I'd seen a few how-to threads about this but all were kind of vague about wire placement, and most concerned the older style alternators.
-
#5
by
Syncroincity
on 09 May, 2014 00:18
-
They offer powdercoated housings also for 45.00 in any color
This would be nice... All my AL components look like absolute crap.
-
#6
by
rodpaslow
on 22 Sep, 2014 22:01
-
[/URL][/img]
-
#7
by
rodpaslow
on 22 Sep, 2014 22:02
-
-
#8
by
rodpaslow
on 22 Sep, 2014 22:06
-
I added this picture as I have an older 1Z/AHU alternator with the back plastic off and I removed brushes as I will likely replace them. I cannot tell with this one if a set (these stand upright towards the camera) is connecting to the diode. Is there a trick to telling what does and what does not?
-
#9
by
rodpaslow
on 22 Sep, 2014 22:14
-
Are the center ones part of the diodes? Can a person use a ohm meter to test connectivity to them?
I saw on another site (4 x4 of some kind) had a picture quite similar and connected a wire to one of the six and his worked. I'm assuming like the one above it matters which of the six. do I need to take it apart further to see which are which?
-
#10
by
rodpaslow
on 24 Sep, 2014 01:10
-
If you go from the top clockwise I tried the 4th one. No dice, did not have the signal or check with mutimeter. This post has a different alternator to start with, but I see the end posts both are useable. I'm going to try one of the end ones next. Pulled the alternator apart, nothing inside helps to determine which post will work.
-
#11
by
vanbcguy
on 24 Sep, 2014 11:10
-
There are quite a lot of usable alternators that do have the 'W' terminal for what it's worth. I have a 120A serpentine one. For some reason a lot of the ABA motors have an alternator that came with a 'W' terminal, so there are loads of them available.
-
#12
by
rodpaslow
on 24 Sep, 2014 12:05
-
vanbcguy, I have a ABA unit (that's what the car originally had in it) serp. I haven't even looked at it thinking it would not be worth even trying it assuming the mounting would be different and no W. Let me have a look at it later today as it is from an Can ABA motor. If it doesn't have a W I will certainly buy the one you have - maybe pm me price just in case.
-
#13
by
vanbcguy
on 24 Sep, 2014 18:11
-
-
#14
by
GEE-BEE
on 24 Sep, 2014 22:24
-
Same one I used on my White alternator
GB