Is this a W terminal alternator?

[92EcoDiesel Jetta]

I snapped this pic of the alternator p/n 175 903 023P on my 81 Caddy before it got dark and didn't have time to investigate further. There is a plug with 3 wires going to the alternator, there are no screw terminals or spade lugs like the alternator on my 92 Eco. Having 3 wires suggests it is a W terminal alternator: One wire to the battery for charging, one wire for the excitation. I am hoping the 3rd wire is the W terminal and I hope it runs all the way up to the correct pin in the cluster connector. I just modded a gasser tach to diesel per regcheesman's writeup and looking forward to installing it and see if the tach works.

[CarlosA]

Don't you own a flashlight? lol

I have a very similar alternator with only a few digits different in the numbers. Mine has a W terminal and the photo below shows where it is (right side of the back of the alternator when sitting in its mounted position).




And here is the tag on mine:

[JamesT]

The three wires in that plug are B+, B+, and D+.  The two fat red ones go to the battery (sometimes by way of the starter motor) and the other one, usually blue goes to the charging light.
My alternator has a terminal that looks like the W on the second one posted, but isn't a W signal.

[92EcoDiesel Jetta]

The three wires in that plug are B+, B+, and D+.  The two fat red ones go to the battery (sometimes by way of the starter motor) and the other one, usually blue goes to the charging light.
My alternator has a terminal that looks like the W on the second one posted, but isn't a W signal.

Thanks for the info! Looks like I'm gonna have to pull the alternator, solder a wire onto a diode and make it a W terminal unit. At least it looks easy compared to my 92 Eco with AC, one belt and it's off!

[RabbitJockey]

Autozone alternators have w terminals and cost about 60 bucks

[92EcoDiesel Jetta]

Autozone alternators have w terminals and cost about 60 bucks

Good to know! What year and model should I ask for? Note that mine makes the connection to the alternator via one 3 prong molded rubber plug (with 3 female spade terminals in it). No AC.

[RabbitJockey]

My car is an 81 Rabbit pa with ac

[92EcoDiesel Jetta]

My car is an 81 Rabbit pa with ac

Does "Autozone alternators have w terminals and cost about 60 bucks " still apply to my Caddy?

[RabbitJockey]

My car is an 81 Rabbit pa with ac

Does "Autozone alternators have w terminals and cost about 60 bucks " still apply to my Caddy?

yes, the only difference is the ac. just go order one, if it shows up with out the w terminal tell them you don't want it, it doesn't cost you anything.  i ordered 4 alternators through napa, the first one i just hope it was right, then the second one they actually called the warehouse and told them specifically not to send it unless it had the w terminal, they did that 3 more times, then i just went to autozone.  i work for napa and get an employee discount so i was trying to go there first.

[92EcoDiesel Jetta]

My car is an 81 Rabbit pa with ac

Does "Autozone alternators have w terminals and cost about 60 bucks " still apply to my Caddy?

yes, the only difference is the ac. just go order one, if it shows up with out the w terminal tell them you don't want it, it doesn't cost you anything.  i ordered 4 alternators through napa, the first one i just hope it was right, then the second one they actually called the warehouse and told them specifically not to send it unless it had the w terminal, they did that 3 more times, then i just went to autozone.  i work for napa and get an employee discount so i was trying to go there first.

Autozone only has the AC alt ($59). The non AC alt is $79 but not available from their supplier so I', SOL. I already have my alternator out and will take the cover off to get to the diodes and bring the W terminal out. This Motorola alternator has the regulator in a separate module from the brushes, unlike the Bosch which is in one assembly. Did 81 Caddy w/o AC come with Motorola alternators exclusively or did it also come with Bosch?

[srgtlord]

The truck my cousin has sitting in his yard has the the motorola alternator, so I am goin out on a limb and saying yes.

[R.O.R-2.0]

The truck my cousin has sitting in his yard has the the motorola alternator, so I am goin out on a limb and saying yes.

Motorola alts were junk.. i just scrapped a big pile of them.

i always replace them with bosch units. ive found that the early-ish rabbits had the moto..

but the motorolas were interchangable with the bosch unit, and cheaper, so people often times bought the moto as a replacement for the bosch.

[92EcoDiesel Jetta]

The truck my cousin has sitting in his yard has the the motorola alternator, so I am goin out on a limb and saying yes.

Motorola alts were junk.. i just scrapped a big pile of them.

i always replace them with bosch units. ive found that the early-ish rabbits had the moto..

but the motorolas were interchangable with the bosch unit, and cheaper, so people often times bought the moto as a replacement for the bosch.

Why are Motorola alt junk and what fails in them?  Do you have a good Bosch non AC alt with a W terminal you want to sell?

[92EcoDiesel Jetta]

I've soldered a wire to the diodes to bring out the W terminal (shiny solder spot at 10 o'clock in the pic). Next reinstall then test and see if the tach works.

[RabbitJockey]

i hope you have put it in the right spot, other wise you could potentially be supply the tachs w terminal with un regulated voltage, to create a w terminal i believe you want to tap into just one of the three black wires.