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  View original topic: Generator Testing
boomtown Fri Feb 05, 2016 10:26 am

I'm trying to test the no load voltage on the generator on my 65 bug. this is the first step in trouble shooting the generator according to the Bentley manual. Located on page 16 of the electrical section of the manual has me disconnecting the wire on the B+ terminal on the regulator and attaching the VOM meter according to the illustration Fig. 6-1. Problem, the engine stops when either of the two wires attached to the B+ terminal are removed. The wiring diagram for a 65 bug has two wires connected to terminal B+ , one goes to the starter and the other runs through the light switch and on to the fuse box.

My question, what am I doing wrong or what is hooked up incorrect?

David

KTPhil Fri Feb 05, 2016 10:30 am

I believe you remove the two wires from the B+ terminal but then connect them together for the test. Don't the instructions say that?

boomtown Fri Feb 05, 2016 11:12 am

The Bentley manual does not say that, it just says disconnect the wire from the B+ terminal and be careful not to ground it. When it said the wire I found it confusing because there are two wires. I tried one wire at a time but each single disconnect stop the engine.

So I understand this correctly you think I need to disconnect both wires and jumper then together? then run the test?

David

KTPhil Fri Feb 05, 2016 11:54 am

I don't have the Bentley handy, but try this procedure:

http://www.autozone.com/repairguides/Volkswagen-Ai...52802674e9

sjbartnik Fri Feb 05, 2016 12:41 pm

I have done this test successfully. Yes even though the Bentley does not explicitly say it, you need to disconnect the red wires from B+ and then connect them together (you can use an alligator clip or something, just make sure they cannot ground on anything).

The reason this is necessary becomes obvious if you understand the current flow from the battery. To do the no-load test, you must take the battery out of the circuit which is what happens when you remove the wires from B+. Of course when you do this, you are cutting power from the battery to the fuse box. No power to fuse box = no power to coil = ignition system no worky = engine stops.

So. Turn off engine. Pull wires from B+ and connect them together. Start engine and perform no-load test.

boomtown Sat Feb 06, 2016 7:29 pm

Thanks sjbartnik for your input. Since starting this thread I have taken the bug to a local man to have the generator checked. It is bad and my next step is to remove the generator and replace it with a new or rebuilt one. thanks for the excellent help and the quick response . as I have found here on the Samba and at local Volkswagen shows and meets, the VW community is most friendly and helpful groups in the automotive hobby.

David

scottyrocks Mon Jul 30, 2018 2:32 pm

Could a faulty generator be the cause of no spark from the coil? I'm running out of ideas as to why I'm not getting spark.

Cusser Mon Jul 30, 2018 3:25 pm

scottyrocks wrote: Could a faulty generator be the cause of no spark from the coil? I'm running out of ideas as to why I'm not getting spark.
Not likely.

If your engine spins at normal speed when you try to start, then you need to first determine whether the issue is fuel-related or spark-related. That's always the first step, use aerosol starting fluid, spray into carb, floor pedal, try to start (do this all several times). If it runs for a few seconds, then likely fuel related; if not, likely spark related.

Or bring VW to Arizona once it gets below 110F here, I'll fix or determine exactly what's the cause in under 15 minutes.

scottyrocks Mon Jul 30, 2018 6:31 pm

Cusser wrote: scottyrocks wrote: Could a faulty generator be the cause of no spark from the coil? I'm running out of ideas as to why I'm not getting spark.
Not likely.

If your engine spins at normal speed when you try to start, then you need to first determine whether the issue is fuel-related or spark-related. That's always the first step, use aerosol starting fluid, spray into carb, floor pedal, try to start (do this all several times). If it runs for a few seconds, then likely fuel related; if not, likely spark related.

Or bring VW to Arizona once it gets below 110F here, I'll fix or determine exactly what's the cause in under 15 minutes.

Well, I'm not getting to Arizona anytime soon, so I'll have to rely on guidance here and/or from local sources.

I'm almost positive I'm not getting spark from the coil, not with 2 separate coils, and two different wires, and a new spark plug.

I traced all the wires attached to the coil and can't find any issues. Everything is attached to where it was when the car ran. I even swapped out the proper fuse (#1) under the dash.

I'll try the spray test.

Sharp64 Mon Jul 30, 2018 6:53 pm

boomtown wrote: Thanks sjbartnik for your input. Since starting this thread I have taken the bug to a local man to have the generator checked. It is bad and my next step is to remove the generator and replace it with a new or rebuilt one. thanks for the excellent help and the quick response . as I have found here on the Samba and at local Volkswagen shows and meets, the VW community is most friendly and helpful groups in the automotive hobby.

David

Just to let you know, there is a company in Orlando(Pine Hills) called TRS. They recently rebuilt my 12v generator. Quick and have a good rep. May be worth a call.

sjbartnik Tue Jul 31, 2018 7:52 am

scottyrocks wrote:
I'm almost positive I'm not getting spark from the coil, not with 2 separate coils, and two different wires, and a new spark plug.

I traced all the wires attached to the coil and can't find any issues. Everything is attached to where it was when the car ran. I even swapped out the proper fuse (#1) under the dash.

I'll try the spray test.

Just so you know, the coil is not fused. It will work whether or not the fuse is in place - assuming your car is wired correctly as VW wired it from the factory.

Not sure how you can be almost positive you don't have spark? You either have spark or you don't. Pull one of the plug wires off and hold it near the case and crank the engine by hand or have someone crank it over using the starter. Look for the spark.

If you're not getting spark and you've tried 2 different coils, my first thing would be to get my VOM out and make sure the coil is getting 12v on terminal 15 and then my second thing would be to check out the points.

Cusser Tue Jul 31, 2018 7:54 am

Check again



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