some 88-90 ABS wheel sensor info

[KDirk]

Dave Lemke (Daves89) recently donated me a chewed up front wheel speed sensor of the no-longer-available Teves variety to play around with. After having messed with it some, I have determined there is no way to connect a new wire lead to the sensor end (internally) without destroying it. This leaves the possibility of splicing on a new cable with connector on outside the molded sensor shell and sealing it to be weather tight at the splice as best as can be done, in order to reuse existing sensors.

My initial research has found that the connector used on the sensor side harness is an AMP/Tyco Econoseal 2 series e/eh/ehm receptacle with socket contacts. The actual part number (from Tyco Electronics site) looks to be 1-827438-9. There is a number embossed in the connector shell 1-926172, though this is not a part number but perhaps a mold number. These connectors are apparently still available (cannot find a stocking distributor though) but are of a design that dates back to at least 1982, per the engineering drawings I downloaded.

Interesting to note that this connector series was developed by AMP's German division, AMP Deutschland GmbH. All notations on the drawings are in German. This likely explains why Teves (also a German firm) chose this connector series for the sensors, as they are unlike anything GM commonly used at the time.

Anyway, my thinking is that if these connectors could be sourced retail (i.e. not in lots of 1500-2000 minimum) that with the addition of coaxial lead wire of the proper impedance, used sensors could be rebuilt and used provided the sensor head itself was still good (easy enough to confirm with a resistance check).

Putting a new lead wire and connector on on does not look like it would be terribly difficult, it is only two wires and the splices would simply have to be covered with moisture inhibiting sealant (dielectric grease?) and covered with heat-shrink. The only remaining problem would be fitting replacements for the molded-on retaining grommets on to the new lead wires. That is something I will need to look at further.

Anyway, this may provide some hope for salvaging some of these sensors that would otherwise go to scrap for lack of a means to repair and reuse. Any thoughts or feedback are welcome.

KDirk

[Guest Mike_s]

There's heat shrink with a meltable interior which might work for locking out moisture, not sure how well it work with the silicon grease though.

[KDirk]

Mike,

Good call. I've seen that before, but hadn't given it a thought until you mentioned it. The big challenge now is to find a source for these connectors that doesn't require a large lot purchase, as none of the usual distributors have this line in their catalog anymore. Probably considered obsolete, as there have been many new and better connector types developed in the ensuing 3 decades.

I could probably get Allied or Mouser to order them in, but have to find out what the minimums would be. Also, the pins/mating receptacles are purchased separately and look to require special crimp and insertion tooling. Yet more expense.

Right now I have other higher priority projects, so I will probably not rush into anything on these unless there is a sudden large demand for me to attempt doing this. Nonetheless, I figured I would put this out there to gauge the feedback/demand from other forum members, and to get and additional ideas. Clearly, it has already started to pay off in that regard.

KDirk

[NCReatta]

About how much are we talking price wise for 1500-2000 connectors?

[KDirk]

Marck,

Probably under a dollar each, but would still need to buy the pins (actually, sockets in this case as they are female on this type of connector) to populate the connector shells as well. So, the total outlay with a bulk purchase would still be rather substantial. Furthermore, I would want to have proof that a fix like this would work by doing a small number (20 or so) of sensor rebuilds and field testing them on a number of vehicles before making that kind of commitment.

Let me see what I can come up with, as I may be able to make a sample request, or get one of the distributors I deal with to order in a more reasonable quantity.

KDirk

[padgett]

If can do a good splice at the sensor end, why not also at the connector end ? Usually the last foot or so is good. Just need the whole bad sensor assembly.

The BWD ABS600 front and ABS1466 rear seem to still be good part numbers but over $100 each today.

BTW I cantacted BWD about updating their e-catalog but didn't seem very interested.

[KDirk]

Padgett,

You raise valid point, but it would be my personal preference to do only one splice, and replace the rest. I guess I look at it this way, one splice is already cause for concern, and may be prone to failure due to heat and mechanical stress/movement despite the best efforts to perform a electrically and mechanically solid splice with good moisture protection.

Since the connector is a part that can be replaced (assuming availability) it makes sense to me to do so, and splice the new coaxial cable at the sensor end so there is only that one splice. Maybe I am going overboard with this approach, we could try to splice at both ends and field test such a repair on-car. If it worked long term, then we have an inexpensive, relatively easy repair that is within reach of anyone who knows how to solder properly.

You mention that BWD still shows front and rear sensors, am I to understand they are still available? Or is the front part number in their catalog a "dead part", that if ordered, gets kicked out? I ask because I was of the impression that the fronts were no longer available anywhere (short of used parts) which is why I started looking at this to begin with.

KDirk

[padgett]

The BWD (Borg Warner Division) ABS1466 is listed as a front sensor for a 1990 Bonneville but not as a rear Reatta (what I meant about getting the e-catalog corrected). Short of removing one entirely from a car, it appears identical to the rear sensor in a Reatta. I bought one from Advance (with coupon) to find out less than a month ago & checked against the foundling since I have the rear end in the air and the wheels off.

The ABS600 is shown as a Reatta front but only for 1990 (Reatta is the same 1988-1990).

So it is not so much that they are unavailable as that the catalog does not list them. The problem is that mislisting is often the first step toward discontinuing since people needing do not order so volume drops.

Of course one member may now buy out the entire on-hand stock and kick the volume up 8*).

So far I have been able to remove cracked/brittle insulation from quite a few, treat with Liquid Electrical Tape, and they seem to be lasting.

The ones that seem unavailable (have ordered from several sources but get kicked out) are the Raybestos ABS 530067 (front) and ABS530079 (rear)

Edited July 20, 2011 by padgett (see edit history)

[Guest Mc_Reatta]

Kevin, You need to look more closely at the problem component of this assembly. While you have looked at the ends, you haven't researched the cable. You'll find it to be the most challenging part to replace. This isn't a simple piece of coaxial cable that you can pick up at Radio Shack.

You will find it is a low loss, 2 conductor, ultra flexible signal cable with shield, and an armor shield and a outer covering that is resistant to most chemicals and moisture and has an extreme operating temperature range. I found one suitable replacement from Belden I believe, but as you found out about the connector, it was not inexpensive and only available in 1,000 foot reels.

The grommets that hold the cable in place and pass thru the fenders are not stock, and would have to be custom molded as well onto the proper locations on the cable.

My gut feel was to also install a connector at the sensor end as well, so it would be easier to replace the cable portion separately, or to add a new sensor down the road if needed, once a new sensor was found that would work as a suitable replacement.

If you want to produce a OEM quality replacement for these sensors, you are going to have to invest a substantial amount of money in order to make one.

As long as they are still available from suppliers it would not be cost effective to bother. If you are handy with a soldering iron and know how to do a weather proof splice and can mold you own strain relief grommets, you can do a cable replacement yourself, but I don't think it will last as long as an original, and this is not going to be a repair that most on this forum are going to want to undertake. A bad job with cheap cable won't last very long at all in the environment of a wheel well.

[padgett]

Sensor sure looks like a single insulated conductor, cellophane wrap, braided shield return, and rubber insulation that gets cracked/brittle/flakes after a couple of decades.

Edited July 20, 2011 by padgett (see edit history)

[Guest Mc_Reatta]

Either you have uncovered another error in the FSM Padgett, or an area where Buick decided to cut costs that results in these sensor wires not being as robust as they should be.

A single conductor with shield will work electrically, but is not what is depicted in the diagram in the FSM, and is the reason why a nick in the outer insulation results in an early failure of the wire.

Attachment shows 2 wires and a drain (shield) for these cables.

I would not recommend replacing these cables with what's shown in your photo unless you really like rewiring these cables frequently.

There are many microphone and headphone cables that are around ( 2 conductor shielded signal cables) at a decent price that would outperform and outlast what is in that photo. Problem is that the less expensive ones won't do that well in the extreme environment of those wheel wells either.

Has to be flexible as the wheel goes up and down thousands of times, at any temperature from ~ -40 to + 140 deg. F, resist water and petroleum products and resist nicks and cuts from rocks, and other FOD that will wiz past them as they go down the road. If the second conductor wasn't the shield, but its own wire within its own separate insulation, a nick in the outer insulation that exposed the shield to the elements wouldn't take the wire down like it did in the photo.

[padgett]

Think I remember seeing the two conductor used on the vehicle side going to the EBCM but single conductor/shield return is how the sensor/front cable was made (and am pretty sure is OEM, why I showed the head with the 1646478 p/n).

[KDirk]

MC,

You are correct on all counts cited. However, as in Padgett's posted picture, the cable used is only one true insulated conductor, and a braided shield is used as the second conductor. There is a cellophane wrap over the shield and under the outer layer of insulation, not even a foil layer on the sensor I have here. Perhaps this was not the original design (later revision?), or perhaps GM's documentation is wrong [again].

Given that the sensor I have here in front of me is the same as the one Padgett has posted the picture of, and that the sensor head has Teves logo molded into it [making it original equipment, not aftermarket] I suspect that GM has the wiring diagram wrong, or at least based on early design data from Teves, which was subsequently changed/downgraded.

Further, the cable type is a rather standard issue coaxial (almost like microphone lead) cable. I have assumed it was a high-temperature/high-flexibility type from the start, but outside of that it is nothing special. A comparable if not better cable could be found to fabricate replacement leads. Cost would, as you pointed out, probably not be insubstantial for the required minimum order of a suitable replacement.

The grommets are a problem, as mentioned in my first post of the thread. There is no good (read: easy) way to address that issue that I see. Of course, my whole reasoning in looking at this was the [now apparently erroneous] belief that the sensors are no longer available, thereby making such a repair necessary. So, I will shelve this for now and work on other things I have in the pipeline.

KDirk

[Thriller]

MC_Reatta - I'm not going to dispute your assertions, but it doesn't really need the extreme cold rating any more does it? My Reatta would be one of the few that would actually see -40 temperatures ever again and it is not intended to ever move in that sort of winter environment again (if I needed an extra vehicle in the winter, I'd start with the '75 Electra with a bunch of weight in the trunk). I understand that some folks drive their Reattas daily and year-round, but with each passing year, they become more of a collectible car than a used car, so perhaps using cable that isn't rated automotive spec (or mil spec) wouldn't be a huge deal. Shoot, if the cable is the primary failure mode, then the ability to replace the cable with an inexpensive solution may still be a very economical way of doing it, although perhaps not overly elegant nor with high reliability.

Just a thought....

[wws944]

...BTW I cantacted BWD about updating their e-catalog but didn't seem very interested.

Probably talking to the wrong person. Need to go back to the companies that sell the interchange information to the manufacturers.