1986 Golf 1.6 N/A Crank No Start

[TylerDurden]

Apostrophe. 

Hrmmmm... 12.6 is too low for alternator output to maintain the charge. It should be at least 13.5V.

I usually tighten the idler pulley locking nut (17mm) finger tight, so the post won't rock, then tighten the 13mm tensioning bolt just until I can't turn the alternator fan by pushing it with my thumb. Then, I snug the locking nut pretty good, which can add a smidge more tension.

[air-cooled or diesel]

if you have plenty of ground and alt checks out then check charging wire. you need to read above 13.5 to get a good charge. you can get a red wire and run it from alt bolt to battery or starter.
check also if you have a ground connection in the back of alt that its hooked up as well.
you dont want alt belt too tight, about tight enough so alt will barely turn by hand.(turn by pressing on fan).

[mtrans]

Hrmmmm... 12.6 is too low for alternator output to maintain the charge. It should be at least 13.5V.

Yes,but if accu is bad then you have that.If you can put good accu read again.

[scrounger]

Assuming that your gauge is reasonably accurate, why are you not getting the full voltage. Has it come up after driving? Do you have your glow plugs stuck on? They could draw the full output nearly of your alternator. Perhaps another short maybe a ghetto blaster stereo.

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?

[jhax]

Well the belt still squeaks under load. So ill go out and go through the tensioning process tylerdurden mentioned and ill update.

Justin

[8v-of-fury]

If its tensioned and still squeaks you either need a new belt.. or to dress the pully's.

[jhax]

So i went with tylerdurdens method and back to square one, absolutely no charge, damn it, i drove parked and started it several times today. Im letting the battery charge now, i alternated tightening both bolts. If i needed to loosen one slightly for fine tuned adjustments, which one is best to loosen?

[TylerDurden]

The 13mm bolt adjusts the tension, the 17mm nut locks the idler post position.

I find that if the the idler post nut (17mm) is too slack, the belt will tighten more than i want after adjusting the tensioner and snugging the post.

So, I keep the 17mm nut finger-tight or tighter, to keep the post perpendicular to the belt, since the tensioner has significant mechanical advantage to move the post.

A 17mm box-wrench is my choice for the idler post, a 13mm flex-head gear-wrench is handy for the tensioner bolt.


But, I don't think tension is the primary problem. Connections are 90% of all electrical issues, in my experience (automotive and otherwise).

[jhax]

Alright, so I guess ill get a new wire going, one end will be an eye connector bolted to the alternator to battery B+ and the other a spade connector to the indicator light out. Does that sound kosher?

[TylerDurden]

I would perform a test first, just using a clip-lead or small jumper. It only needs to be connected momentarily... after the alternator is producing current, it should self excite.

I would:
Ensure the B+ cable has 12V at the alternator
Put a DMM on the battery terminals
Start the car
Clip the jumper from the B+ to the D+
Rev the engine once to  1500-2000rpm

If the DMM indicates >13.5, unclip the jumper and verify continued output. If good, alternator is ok... trace the blue wire for internal breaks.

If the DMM indicates no charging, O'reilly may have botched the bench test.

[jhax]

I would perform a test first, just using a clip-lead or small jumper. It only needs to be connected momentarily... after the alternator is producing current, it should self excite.

I would:
Ensure the B+ cable has 12V at the alternator
Put a DMM on the battery terminals
Start the car
Clip the jumper from the B+ to the D+
Rev the engine once to  1500-2000rpm

If the DMM indicates >13.5, unclip the jumper and verify continued output. If good, alternator is ok... trace the blue wire for internal breaks.

If the DMM indicates no charging, O'reilly may have botched the bench test.

Okay sir, here are the results...

Took the battery off the charger.
12.4V  battery terminals
12.36V negative batt terminal to pos post on alt

Key on ACC
11.4V batt terminals

Car start and idle
11.43V (lots of belt squealing, rev throttle until no more squeaking)

Attach jumper wire (one end post terminal alt another attached on blue alt excite wire spade connector), blip throttle
11.83V batt terminals

So perhaps botched bench test...

[scrounger]

Something is not right. The belt squealing indicates to me that the alternator is powering up (Developing voltage and amperage).  Is the wire that goes from your alternator to the battery good or perhaps a loose or open connection. Might measure the voltage at the main alternator terminal. Keep your hands free of the belt. Is there something else loading down your system. Like a stuck glow relay?

Of course the alternator might be weak too.

[jhax]

I have been measuring the voltage at the terminal ON THE BACK of the alternator the whole time, never at the starter. Even at the terminal (B+) i am not getting an output voltage higher than what the battery is.

[jhax]

As for the glow plug relay, the LED shuts off indicating that the relay is shutting off? I can measure the voltage going to the glow plugs via the black wire that connects to the copper strip going to the plugs?

Justin

[TylerDurden]

The yellow indicator is a timer indicator, not the actual voltage to the GPs.

After the engine is running for 30-60 sec, check the GP buss for voltage. Any point on the GP buss should do as a test-point.

A stuck GP relay could drag down the voltage. Plus, the original issue was burned out GPs, so the relay could be bad.