1986 Golf 1.6 N/A Crank No Start

[jhax]

Okay, i just got back from testing it and here are the results...

ACC position:

BLU: 0V   Y/R: 1.5V

Idling after throttle (LED shuts off):

BLU: 11.6V Y/R: 11.6V

ACC (after shutting the car off and turning it back to position):

BLU:1.5V  Y/R:12V (thinking it may be some residual left in the system, if there is such a thing)

Point being, the circuit is working and it seems like the alt excite wire is not faulty. So this leaves me with two options, grounding issue and or bad alternator. Input, thoughts, feelings, general outlooks on life? Thank you guys for the help by the way, i really do appreciate it.

[TylerDurden]

If the LED lights up, then shuts off when the engine is running, the circuit between F21 and the alternator is likely OK.

If there is only ~12V  at the battery terminals with the engine running and the LED off, the alternator is failing, or grounding path is resistive. Should be 13.5V-14.2V.

[scrounger]

Testing your car at midnight, impressive.
I would say that the alternator is kaput. Hope you can get it going.

[TylerDurden]

Watch out for curve-balls...

I went out yesterday to test my 89 and validate my understanding, but the battery was dead.

Same symptoms as the OP... even heard the belt squeal oddly a few days ago.

I changed the regulator ( I keep spares from cores).  But there was no change, no charge.


Today I was starting to replace the alternator and discovered this:



Old, stiff insulation can keep the wire in the ring-terminal's collar, especially when the strain-relief is so close. There was enough broken wire touching the ring-terminal to light the LED, but not enough to energize the field.  

I replaced the ring-terminal and all is well.

[LOBOTAC]

try fixing the problem you have with your belt squeeling.  Had similar issues until i got rid of my ac.

[jhax]

Scrounger, god damn right haha! when you have a car that is so simple you can take out the cluster in 10 minutes it makes life easy. I just want to be absolutely clear, our alternators are alternators right? not generators, therefor the voltage regulator is inside the alternator not outside. I will drive my car to o'riley today and take out the alternator to get it bench tested. I ordered another one and it will get here in 7 days.

[tyb525]

...therefor the voltage regulator is inside the alternator not outside...

Many older alternators had external regulators. My '85 dodge ram has an alternator external regulator, it's mounted on the firewall.

[jhax]

Turns out the vws have alternators (regulators included). Anyway, I took the car to the auto parts store today to get the alternator tested and it tested fine. So i guess its down to a grounding issue.

[R.O.R-2.0]

Scrounger, god damn right haha! when you have a car that is so simple you can take out the cluster in 10 minutes it makes life easy. I just want to be absolutely clear, our alternators are alternators right? not generators, therefor the voltage regulator is inside the alternator not outside. I will drive my car to o'riley today and take out the alternator to get it bench tested. I ordered another one and it will get here in 7 days.

VW hasnt used generators since the 60s..

generators make their own power without being energized..

Alternators, wether they have internal or external regulators, need to be excited before they will charge..

VW has NEVER, that im aware of, used an external regulator pack..

[jhax]

I am about ready to punch a baby. Alternator tested fine. I spent 2 hours adding 2 ground wires, one from the alt body to where the battery ground wire bolts to the trans housing. And another from the ground battery cable to the stud where the washer bottle nut holds the washer bottle in place. And STILL NO CHANGE! I still am not getting any voltage from my alternator to my battery.

[scrounger]

why don't you try jumping from the battery to the alternator blue wire.  Actually just from the Red to the blue.

[TylerDurden]

Let's be sure: the ignition switch is in the ON (run) position, but engine not running.

Meter between battery neg and blue at D+ terminal should be ~1.5V. LED illuminated.
Meter between battery neg and big red at B+ terminal should be ~12V.

[jhax]

Let's be sure: the ignition switch is in the ON (run) position, but engine not running.

Meter between battery neg and blue at D+ terminal should be ~1.5V. LED illuminated.
Meter between battery neg and big red at B+ terminal should be ~12V.

Meter between battery neg and blue at D+ terminal is 1.25V.
Meter between battery neg and big red at B+ terminal is ~11.8V (drove to the grocery store and back)

[jhax]

PS I tightened the *** out of the belt. At first i wasnt sure how the damn thing tightened and i realized the slot on the bracket below the alternator. It it a combination of tightening both the bolt on the tensioner and on the rad side of the bracket so the pulley is parallel with the AC pulley and tight. I believe squeaking can be caused by the pulley not being parallel.

[jhax]

I may have had an apostrophe, lightning has just struck my brain. So that whole bit about tightening the two bolts in the right pattern? order? So that the belt does not squeak. After doing some adjustments, the belt didnt squeak as much and I got a charge! I drove around with the AC on high and high beams on. Pulled back in my space and it read 11.8v but as soon as I turned all accessories off it held steady at 12.5-12.8V. Turned the car off and held at 12.6V so the pulley adjustments seemed to have worked. The real test is to go to school and my job interviews and safely make it home without jumper cables. So my next question is, is there a procedure for adjusting the tension on the belt? Tighten one bolt all the way before the other? Tighten each one little by little?