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bilbo939
Samba Member
Joined: July 15, 2020
Posts: 59
Location: Isle of Wight, UK
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 Posted: Sat Mar 06, 2021 11:32 am Post subject: Alt light issue. |
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Hello all,
Started having issues with my alternator light today, on my 71 super(engine was converted from generator years ago by PO no issues)
When the key is off, nothing happens, which is fine.
When the ignition is on netheir the oil or alt light come on but the indicator light flashes as if the hazards were on but really fast.
When you start the car the indicators go back to behaving normally, but the gen light comes and stays on.
The car is charging just fine, and the light cluster is getting 12v from the fuse box along their shared 12v.
Im a bit of a electrical newbie, so please be gentle.
_________________
'71 1302-S
'03 T4 2.5 TDI
'04 Golf 1.9 TDI |
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Starbucket
Samba Member
Joined: April 30, 2007
Posts: 4025
Location: WA
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| Posted: Sat Mar 06, 2021 3:00 pm Post subject: Re: Alt light issue. |
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| Maybe the brush under the plastic plate the indicator light wire connects needs to be replaced, it's held down with 3 screws. You need to see 13.5 volts min. at idle. Fan belt is tight right? |
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bilbo939
Samba Member
Joined: July 15, 2020
Posts: 59
Location: Isle of Wight, UK
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| Posted: Sat Mar 06, 2021 3:42 pm Post subject: Re: Alt light issue. |
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| Starbucket wrote: |
| Maybe the brush under the plastic plate the indicator light wire connects needs to be replaced, it's held down with 3 screws. You need to see 13.5 volts min. at idle. Fan belt is tight right? |
It was a little low, 13.44-13.46 volts when running but was on its way up. We recently had some super cold weather and the battery was sat for a while before that. Belt is good but could probably do with an adjustment/check anyway. Would that brush mess with the alt light and oil light too?
P. S when I said "12v" before I just meant it was getting power along there it wasn't a measurement sorry
_________________
'71 1302-S
'03 T4 2.5 TDI
'04 Golf 1.9 TDI |
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Starbucket
Samba Member
Joined: April 30, 2007
Posts: 4025
Location: WA
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| Posted: Sat Mar 06, 2021 4:14 pm Post subject: Re: Alt light issue. |
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| bilbo939 wrote: |
| Starbucket wrote: |
| Maybe the brush under the plastic plate the indicator light wire connects needs to be replaced, it's held down with 3 screws. You need to see 13.5 volts min. at idle. Fan belt is tight right? |
It was a little low, 13.44-13.46 volts when running but was on its way up. We recently had some super cold weather and the battery was sat for a while before that. Belt is good but could probably do with an adjustment/check anyway. Would that brush mess with the alt light and oil light too?
P. S when I said "12v" before I just meant it was getting power along there it wasn't a measurement sorry
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No the brush would just be preventing charging. You may want to check the ground wire to speedo indictor lights, clean the connections. |
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VW_Jimbo 
Samba Member
Joined: May 22, 2016
Posts: 9955
Location: Huntington Beach, CA
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| Posted: Sat Mar 06, 2021 10:38 pm Post subject: Re: Alt light issue. |
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Check the ground path.
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Jimbo
There is never enough time to do it right the first time, but all the time necessary the second time!
| TDCTDI wrote: |
| Basically, a whole bunch of fuckery to achieve a look. |
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GFY's Xevin and VW_Jimbo!  |
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ashman40
Samba Member
Joined: February 16, 2007
Posts: 15982
Location: North Florida, USA
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| Posted: Sat Mar 06, 2021 10:39 pm Post subject: Re: Alt light issue. |
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Check the following...
With the ignition switch ON, disconnect the bottom most wire from the speedometer. Test the end of this wire for 12v. Reconnect when done.
Disconnect the blue/red wire running from the turn indicator lamp to the flasher relay. What model flasher relay are you running? Was it meant for a classic Beetle? Not all generic flasher relays will work. Keep this wire disconnected (but not grounded) for the remainder of the tests.
With the ignition switch still ON, go to the engine and pull the blue/green wire off the oil pressure switch just below the distributor. Ground the end of the wire and the OIL lamp in the speedometer should turn ON. If this work, it means your oil pressure switch has failed. If it does not turn the OIL lamp on it means there is a problem between the wire at the speedometer and the end of this wire. Check the OIL lamp bulb.
Do the same test with the blue #61 wire at the VR or the alternator (2-wire alternator). When you remove and ground the wire it should cause the GEN lamp to turn ON. If it doesn’t check the GEN lamp.
Report back your results.
_________________
AshMan40
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'67 Beetle #1 {project car that never made it to the road  }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!} |
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bilbo939
Samba Member
Joined: July 15, 2020
Posts: 59
Location: Isle of Wight, UK
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| Posted: Sun Mar 07, 2021 6:06 am Post subject: Re: Alt light issue. |
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| ashman40 wrote: |
Check the following...
With the ignition switch ON, disconnect the bottom most wire from the speedometer. Test the end of this wire for 12v. Reconnect when done.
Disconnect the blue/red wire running from the turn indicator lamp to the flasher relay. What model flasher relay are you running? Was it meant for a classic Beetle? Not all generic flasher relays will work. Keep this wire disconnected (but not grounded) for the remainder of the tests.
With the ignition switch still ON, go to the engine and pull the blue/green wire off the oil pressure switch just below the distributor. Ground the end of the wire and the OIL lamp in the speedometer should turn ON. If this work, it means your oil pressure switch has failed. If it does not turn the OIL lamp on it means there is a problem between the wire at the speedometer and the end of this wire. Check the OIL lamp bulb.
Do the same test with the blue #61 wire at the VR or the alternator (2-wire alternator). When you remove and ground the wire it should cause the GEN lamp to turn ON. If it doesn’t check the GEN lamp.
Report back your results. |
Bottom most wire doesn't read anything when grounding the multimeter back to the body.
Flasher relay looks like this, so is generic but I don't know enough to comment on its suitability.
I left it disconnected for the rest of the tests. (the wire)
My oil pressure switch wire is green and yellow, it has no effect on the oil light, bulb and holder have continuity.
I believe my alt is internally regulated as there is no VR anywhere, the wiring on it doesn't match anything I can find in any diagram. It's a non branded part by the looks of it. Disconnecting blue #61 from the dial however has no effect. Bulb and holder has continuity.
Also this morning a new symptom, the flasher no longer goes crazy when ignition is on. And only does the hazards when running, indicators no longer work
_________________
'71 1302-S
'03 T4 2.5 TDI
'04 Golf 1.9 TDI |
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gilg
Samba Member
Joined: April 17, 2020
Posts: 62
Location: Fayetteville, AR
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| Posted: Sun Mar 07, 2021 7:54 am Post subject: Re: Alt light issue. |
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| bilbo939 wrote: |
| as there is no VR anywhere, the wiring on it doesn't match anything I can find in any diagram. |
You don’t have a voltage regulator under the back seat, driver’s side?
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'72 Super Beetle - 1776cc w/ dual Weber 134 ICT carbs, Pertronix ignition, glasspack, Rally+ lift springs |
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bilbo939
Samba Member
Joined: July 15, 2020
Posts: 59
Location: Isle of Wight, UK
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| Posted: Sun Mar 07, 2021 8:10 am Post subject: Re: Alt light issue. |
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| gilg wrote: |
| bilbo939 wrote: |
| as there is no VR anywhere, the wiring on it doesn't match anything I can find in any diagram. |
You don’t have a voltage regulator under the back seat, driver’s side? |
Over here it's known as the passengers side 
But no, just a loom running straight through next to the heat pipes.
_________________
'71 1302-S
'03 T4 2.5 TDI
'04 Golf 1.9 TDI |
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ashman40
Samba Member
Joined: February 16, 2007
Posts: 15982
Location: North Florida, USA
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| Posted: Sun Mar 07, 2021 9:17 am Post subject: Re: Alt light issue. |
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| bilbo939 wrote: |
| ashman40 wrote: |
Check the following...
[list]With the ignition switch ON, disconnect the bottom most wire from the speedometer. Test the end of this wire for 12v. |
Bottom most wire doesn't read anything when grounding the multimeter back to the body. |
This is root of your problem.
The bottom most terminal on the speedometer is a shared 12v+ connection for the bottom three indicator lamps. The wire that connects here is powered from the fuse box. On earlier models the black wire came directly from the fuse box. Later, the wire piggy backed off the fuel gauge power. Trace your wire backwards and find where it is connected. Clearly, there is a disconnect between the bottom speedometer terminal and ignition switched 12v+.
A common mistake is to think the shared connection between the three indicator bulbs is a common ground and to run the wire to ground. This shared connection needs to be connected to an ignition switched 12v+ power source. Each of the wires running from these three indicator bulb holders runs to a switched ground to turn the indicator lamp ON.
| bilbo939 wrote: |
Flasher relay looks like this, so is generic but I don't know enough to comment on its suitability.
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That should be fine. The terminal numbers match the stock 3-prong relay. Just confirm:
The #31 terminal is grounded
The #49 terminal (INPUT) is powered from the E-flasher switch “+” terminal
The #49a terminal (OUTPUT) runs to both the turn signal switch, the E-flasher switch and the turn indicator lamp
| bilbo939 wrote: |
| My oil pressure switch wire is green and yellow, it has no effect on the oil light, ... Disconnecting blue #61 from the dial however has no effect. |
Neither of these tests will work if there isn’t 12v+ to the common terminal at the bottom of the speedometer. Get that fixed then retest.
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!} |
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bilbo939
Samba Member
Joined: July 15, 2020
Posts: 59
Location: Isle of Wight, UK
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| Posted: Sun Mar 07, 2021 2:34 pm Post subject: Re: Alt light issue. |
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| ashman40 wrote: |
| Neither of these tests will work if there isn’t 12v+ to the common terminal at the bottom of the speedometer. Get that fixed then retest. |
Thanks, will do. Might be a while before I can get round to it mind so I'll post again once I've made progress.
Car is off the road now now the indicators have stopped working aswell. I have a feeling this wiring harness is pretty fragile and just disturbing it is causing more issues.
_________________
'71 1302-S
'03 T4 2.5 TDI
'04 Golf 1.9 TDI |
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ashman40
Samba Member
Joined: February 16, 2007
Posts: 15982
Location: North Florida, USA
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| Posted: Mon Mar 08, 2021 7:10 am Post subject: Re: Alt light issue. |
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| bilbo939 wrote: |
| I have a feeling this wiring harness is pretty fragile and just disturbing it is causing more issues. |
The harness is just wire and end terminals. If the terminals are loose on the wire, re-crimp or cut off the loose ends and crimp a new one in its place. Use the uninsulated terminals (like below) as they have two crimp points for a solid connection.
If the terminal is loose on the spade it slides onto, tighten the "loops" of the female terminal so they maintain a snug grasp on the male spades. Lightly compressing the loops will increase their grip. You only want to tighten the terminal's grip, not crush it.
Another way is to bend the straight back of the female terminal (underside of the terminal pictured above) just a tad so it presses the male spade from the other side holding it tight against the loops.
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!} |
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