Thoughts on replacing a 7A/3B or early AAN Hall sender

[UrS4boy]

The 7A, 3B and early AANs have a Hall sender in a "distributor". In the 7A and 3B situation, the Hall sender is really in a distributor. In the case of the early AAN, the "distributor" is actually the cam position sender and looks like this one (which I call the "tuna can" dizzy because of the size and shape of the black cover):



Once the distributor is disassmbled (drive gear has to be removed to allow the shaft with the Hall sender shutter wheel and rotor post to be pulled up/out), the Hall sender plate looks like this:

FRONT SIDE:

Original Photo Courtesy of Bill Z.

BACK SIDE:


Original Photo Courtesy of Bill Z.

The AAN "tuna can" Hall sender is an HKZ101, just like the later UrS4s (and ABYs and ADUs) (behind the cam sprocket). As a result, replacement can be an inexpensive Hall sender from BB AutoMacao. The issue is how to connect the BB Automacao sender wires to the plug connector. I think there are two options:

1. decrimping the wires at the connectors (might be tricky) and crimping in the new sender wires or
2. splicing the wires between the new replacement sender and the connector pins (leaving the existing crimped connections intact).


I think if the clips on the white plastic cover are released on the back side as shown, the wires will be exposed better on the opposite (top) side, perhaps making it easier to pull the pins on the connector. If not ,splicing the wires (staggered soldered and heat shrink tubing) or soldering at the crimped connection should work.

Removal of the existing HKZ101 is as easy as the later ones (the one behind the cam sprocket): drill off the top of the two rivet heads.

Thoughts?

[Jonas_R]

I gonna go a bit off topic here, sorry.

Out of curiosity can you still buy the tuna can? And can it be made to fit the 3B engine?

[UrS4boy]

I gonna go a bit off topic here, sorry. Out of curiosity can you still buy the tuna can? And can it be made to fit the 3B engine?

Yes they can still be bought. However, if you are trying to convert a 3B to run an AAN ECU and five coils, I am told that you can simply use the 3B distributor and Hall sender (with some wiring patching into the AAN ECU harness). Hopefully somebody with more 3B knowledge will chime in.

[veneto rs2]

I think there are two options:

1. decrimping the wires at the connectors (might be tricky) and crimping in the new sender wires or


Thoughts?

sliding the old spades from the connector it's not difficult assuming you have the correct tool.
Crimping new connectors in it's not that bad the spades inside are hard to find new thoug (at least in Italy) I have done this on the coils wiring a month ago and the connector (hence the spades) are the same shape.
As long as you have the correct tool to slide them off and the correct tool to crimp the new ones in it want be difficult.
I spent 24 euros for the crimper and 20 euros for the pushing off tool.

Stefano

[Nuvo]

Option 2 is the easiest to do and a perfectly good solution. Option 1 isn't really necessary unless you are striving for perfection, I would suggest that it would be better to replace the pins with new items rather than attempting to decrimp the original pins.
You'll need additional tools too as Stefano explains.

You should be able to source the pins from a good auto electrics supplier.

[UrS4boy]

Options 2 is the easiest to do and a perfectly good solution. Option 1 isn't really necessary unless you are striving for perfection, I would suggest you would be better replacing the pins with new items rather than attempting to decrimp the originals. You should be able to source the pins from a good auto electrics supplier.

I would have thought so, however, I am told that those "pins" are molded into the black 90º connector. (I need confirmation of that).

[Nuvo]

I think you would really struggle to find pins for the 90º connector (I didn't notice this at first). I would tend to agree that you would need to source a new connector as suggested. Option 2 looks to be your best bet.

[mcandmar]

There is enough room inside the unit to splice/solder the wires together if needed. I think the back side of the connector pins had a layer of glue to hold it all in place.

Dizzy is from my 7A, reason for the zip ties is the original plastic cover came loose and got chewed up.

[UrS4boy]

There is enough room inside the unit to splice/solder the wires together if needed. I think the back side of the connector pins had a layer of glue to hold it all in place. Dizzy is from my 7A, reason for the zip ties is the original plastic cover came loose and got chewed up.

Thanks. Flipping the photo 180 deg. I *think* I can read Siemens HKZ101 on the Hall sender. So there is consistency between 7A, 3B and early AAN Hall senders. Drive gears not so much.

[newsh]

There are 2 parts to the crimp, the one around the conductor and the one around the sleeving, I've remade a few connectors like this before. The crimp round the conductor is very difficult to undo so I leave that alone and cut the wire off, the crimp round the cable can be unpeeled. I then solder the new wire to the crimped area that holds the old conductor and then strain relief it with the secondary crimp. You need to carefully clean and tin the pin where you're going to solder to it and tin the end of the wire then quickly sweat them together. Dab of silicon grease to stop corrosion.

[UrS4boy]

There are 2 parts to the crimp, the one around the conductor and the one around the sleeving, I've remade a few connectors like this before. The crimp round the conductor is very difficult to undo so I leave that alone and cut the wire off, the crimp round the cable can be unpeeled. I then solder the new wire to the crimped area that holds the old conductor and then strain relief it with the secondary crimp. You need to carefully clean and tin the pin where you're going to solder to it and tin the end of the wire then quickly sweat them together. Dab of silicon grease to stop corrosion.

Perfect. Thanks very much.

[UrS4boy]

How does this diagram and its labels look?

[Nuvo]

The image is clear and the text instructions are easy to follow.

[UrS4boy]

The image is clear and the text instructions are easy to follow.

Thanks, that was my goal.

(Recently retired consulting engineer, former University prof).

[newsh]