TheSamba.com :: View topic - My alternator puts out 18v @ 2000 rpm. Whats wrong?

Sat Feb 21, 2004 10:48 am

Should I worry? Also when the RPm hits 2000+ the headlights and guages get brighter too. At idle it will read 12.8-14v. I looked for a V-regulator but found a little sealed box under the seat(motorolla) with 4 wires hooked up to it. The motor is stock 1600.

Sat Feb 21, 2004 11:42 am

NEW2OLD73Super wrote: Should I worry? Also when the RPm hits 2000+ the headlights and guages get brighter too. At idle it will read 12.8-14v. I looked for a V-regulator but found a little sealed box under the seat(motorolla) with 4 wires hooked up to it. The motor is stock 1600.

that little sealed box under the seat is the V- reg... both Motorola and bosch made alt's for VW from 73-on... for production... but Motorola dropped by the wayside many years ago on that unit.

sounds like the v-reg is shot... get another... can be the sealed solid state type like you have or the Bosch style...

BTW you do still have a external regulated alternator on the engine right :?:

or I might suspect that someone has put an AL-82 with the internal reg on the engine and did not wire "bypass" the regulator that was existing?

you should confirm which alt you have....

Sat Feb 21, 2004 1:30 pm

The wierd thing is the alternator has a built in regulator.
Out I curiosity I looked under the rear seat and found it.
I bought 2 regulators but they don't look anything like what I found in the car.

Here is a pic of one of the gegs I bought:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?Vi...otohosting

Sat Feb 21, 2004 1:50 pm

The regulator in the eBay auction is for a generator, not an alternator. Do not use it with your alternator.

Your alternator obviously does not have an internal regulator, so you need an external one, and you need the one for an alternator.

Sat Feb 21, 2004 2:37 pm

Thanks guys. OK I khow I have an internal reg. Whats that tiny box under my seat. Theres 4 wires connected to it.

Sat Feb 21, 2004 4:52 pm

Do the wires actually go anywhere or have they been terminated somewhere out of sight?

Sat Feb 21, 2004 5:16 pm

One goes to the battery+ and the rest go through the back on the alternator.

The car runs fine and the batt never died. I'm just a little concern about the high output on 2000+ RPMs.

Sat Feb 21, 2004 9:04 pm

NEW2OLD73Super wrote: Thanks guys. OK I khow I have an internal reg. Whats that tiny box under my seat. Theres 4 wires connected to it.

If you have an AL 82 Bosch ( one post with big red wire and one small spade connection to light in speedo) with the internal reg then you need to bypass the one under the rear seat.
If you have this type and your running it through the external regulator under the rear seat then that is likely the reason for the high output.

If you have an AL 78 Bosch with the big red/ post and 3 spade connections on top then you need the reg under the rear seat.
and something is wrong... like the regulator is shot.

and yes, I would be worried, that is too much output.

Sun Feb 22, 2004 12:28 am

On the alternator there is a three wire plug and 2 posts(1 red and 1 black) a total of 5 wires from the alternator.

I'll try removing the reg and check the output in the morning.

Thanks for all the support guys.

Sun Feb 22, 2004 1:23 am

You can't just remove the reg... you need to bypass it. To bypass it connect the two red wires together, then connect the blue and green wires together. I'm assuming thats the four colors you have... if not, ask again.

EDIT... it sounds like from your description of the wires on the alt that you might need the voltage reg and it may be bad. Are there any numbers on the alt? A sticker of any sort?

Sun Feb 22, 2004 8:18 am

NEW2OLD73Super wrote: On the alternator there is a three wire plug and 2 posts(1 red and 1 black) a total of 5 wires from the alternator.

I'll try removing the reg and check the output in the morning.

Thanks for all the support guys.

Okay! that is what I have been getting at since my first post...what alt was on the engine... now that we know for sure...

You have the externally regulated model ( not an internal one as you previously stated)

so you do need the regulator under the rear seat, and it is shot so replace it...

forget the part about by passing it... ( unless you decide to change to the AL82 in the future, then you would need to bypass the old reg)

Sun Feb 22, 2004 6:13 pm

the alternator # 8AL2034K
the V-regulator #8RH2001
(043-903-803)
(MB2)

Sun Feb 22, 2004 7:20 pm

Not trying to add to the confusion here but:

I have an internal voltage regulator on my stock alternator, and I also have 5 wires coming out of the alt: three are yellow and all connected to one screw on the alt near the fan housing, one is a slide-on connector near the back of the alt, and one is a big fat wire on a screw post also near the back of the alt.

Also, the little box with wires under the seat could be the relay for the rear window defogger. So a beetle with an external voltage regulator would have 2 boxes under the back seat.

Sun Feb 22, 2004 9:39 pm

79SuperVert wrote: Not trying to add to the confusion here but:

I have an internal voltage regulator on my stock alternator, and I also have 5 wires coming out of the alt: three are yellow and all connected to one screw on the alt near the fan housing, one is a slide-on connector near the back of the alt, and one is a big fat wire on a screw post also near the back of the alt.

Also, the little box with wires under the seat could be the relay for the rear window defogger. So a beetle with an external voltage regulator would have 2 boxes under the back seat.

Thanks Joe!...that is adding confusion to an already confused thread! :roll: :wink: :lol:

Sun Feb 22, 2004 10:03 pm

Maybe its just me, but if your engine is a stock 1600 and you found two voltage regulators under your seat like you posted. Are you sure you don't have a generator and not an alternator?

What year is your bus? 71 was the last year of the regulator, which is what I have. If that is the case, then the problems you are describing are due to a busted v-reg like keifernet said.

Mon Feb 23, 2004 1:09 pm

http://community.webshots.com/photo/120594451/120596234eWDRie

Mon Feb 23, 2004 1:10 pm

http://community.webshots.com/photo/120594451/120596402LJuSzE

http://community.webshots.com/photo/120594451/120596310SPkvuN

http://community.webshots.com/photo/120594451/120596571DCbWrf

http://community.webshots.com/photo/120594451/120596832FuNEKb

Mon Feb 23, 2004 2:18 pm

keifernet wrote: NEW2OLD73Super wrote: On the alternator there is a three wire plug and 2 posts(1 red and 1 black) a total of 5 wires from the alternator.

I'll try removing the reg and check the output in the morning.

Thanks for all the support guys.

Okay! that is what I have been getting at since my first post...what alt was on the engine... now that we know for sure...

You have the externally regulated model ( not an internal one as you previously stated)

so you do need the regulator under the rear seat, and it is shot
so replace it...

forget the part about by passing it... ( unless you decide to change to the AL82 in the future, then you would need to bypass the old reg)

the pics tell the tale... it is an original externally regulated alt...

Mon Feb 23, 2004 4:03 pm

I'll keep my eyes open for a regulator.
Hopefully it will sove the over-charging problem.
You guys are the best since slice bread.

Mon Feb 23, 2004 8:48 pm

I have a box full of used ones.. some of the Motorola type you have.

unscrew yours and look at the back... if the "gel" is all bubbly and melted.( I'll bet it is) then it is shot... PM me if you want to try a used one...