'79 Bus engine miss/ coil wires connected backwards and Loose wire question

Find/Fix/Report Back

Moderators: Sluggo, Amskeptic

Post Reply
waterdawg2004
I'm New!
Status: Offline

'79 Bus engine miss/ coil wires connected backwards and Loose wire question

Post by waterdawg2004 » Mon Jun 20, 2016 9:58 am

I have a loose wire that goes from the fuel pump to the distributor( see Pic). Before I plug it back in and maybe burn something out can anyone tell me what it is for? The other one must be power for the fuel pump because it still works but why 2 wires? Thanks for any info. Buck
vw orange dizzy 2.jpg
vw orange dizzy 2.jpg (148.28 KiB) Viewed 8414 times

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: Loose wire question

Post by Amskeptic » Mon Jun 20, 2016 3:26 pm

waterdawg2004 wrote:I have a loose wire that goes from the fuel pump to the distributor( see Pic). Before I plug it back in and maybe burn something out can anyone tell me what it is for? The other one must be power for the fuel pump because it still works but why 2 wires? Thanks for any info. Buck
vw orange dizzy 2.jpg
That is not from any old fuel pump.
That is the double relay power wire and the reverse light power wire. The reverse light wire leads from the inline fuse to the transaxle, the double relay power wire branches *upstream* of the reverse light fuse.
This wire attaches to #15 (+) on the coil.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

waterdawg2004
I'm New!
Status: Offline

Re: Loose wire question

Post by waterdawg2004 » Tue Jun 21, 2016 3:52 pm

Thanks, I read your article on the double power relay, now I know what it is and a vague idea of how it works and where it is. I have a very rough idling engine so according to the manual it says to check voltage at the battery first then check the ignition system. Battery is good 13.15 volts and 782 CCA. So I checked the points and reset them to .40 inch. Tried to connect a dwell meter but I was getting no reading? In looking at the wiring going to the coil is looks like maybe the wires were switched around, the wire to the distributor(green wire) was connected to 15+, when according to the VW Official Service Manual it say "you connect the wire from the ignition switch to terminal 15+ and the wire from the distributor to terminal -1". So I turned the coil around and marked with a paint marker terminal 15 +, see pic. It looks like there are 5 wires to the coil.
1. green wire from distributor to coil= 1-
2. white wire to control module(ECU) =??
3. black wire from double relay= 15+=86c
4. black wire from fuse=15+= reverse lights and maybe ignition switch (see pic)

5.black wire to relay on fan blower. I will leave this wire unplugged, for simplicity:
a black wire which leads to a relay on top of the fan blower, which is unplugged any way?? I do not know what it does, maybe power for fan blower? No heaters in this bus anyway.

The question then is where does the white wire go, 1- or 15+?
And is it normal for the ignition switch wire to go to the reverse fuse and then to the coil?
0000coil wiring small.jpg
0000coil wiring small.jpg (143.65 KiB) Viewed 8393 times

waterdawg2004
I'm New!
Status: Offline

Re: Loose wire question

Post by waterdawg2004 » Tue Jun 21, 2016 3:53 pm

pic deleted

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: Loose wire question

Post by Amskeptic » Tue Jun 21, 2016 11:12 pm

Read my corrections in red.
waterdawg2004 wrote:
points and reset them to .016 inch.
green wire and white wire to terminal 1 (-) coil.

15 (+) on coil has black wire to double relay and reverse lights
black wire FROM relay on fan blower comes FROM ignition switch.
I will leave this wire unplugged, for simplicity: IT IS THE VOLTAGE SUPPLY TO COIL!!

And is it normal for the ignition switch wire to go to the reverse fuse and then to the coil?
Ignition switch wire loops over the heater blower and goes TO ignition coil #15 (+).
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: Loose wire question

Post by Amskeptic » Tue Jun 21, 2016 11:13 pm

waterdawg2004 wrote:other pic
0000reverse and ign wire to coil small.jpg
Delete this picture and the labeling. There is a black wire leading from the fuse to the transmission's reverse switch. From that switch, there is a black wire that is supposed to go the left taillight harness where you will see a connector that branches to the right taillight and the left tail light. I think you have THAT black wire going to the coil to cause mayhem in your mind.

You need an Itinerant Air-Cooled Electrical Practicum.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

waterdawg2004
I'm New!
Status: Offline

Re: Loose wire question

Post by waterdawg2004 » Wed Jun 22, 2016 5:47 am

Thanks, I was just guessing at the wiring, and had it all wrong. Back to the books. Yes I need your help, I am set up to see you July 6th. Happy trails. Buck

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: Loose wire question

Post by Amskeptic » Wed Jun 22, 2016 6:51 am

waterdawg2004 wrote:Thanks, I was just guessing at the wiring, and had it all wrong. Back to the books. Yes I need your help, I am set up to see you July 6th. Happy trails. Buck
Ya like that 2:13AM reply to your post? We are so darndedicateddeadtired this morning . . .
ColinOffToTheMiz
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

waterdawg2004
I'm New!
Status: Offline

Re: '79 Bus engine miss/ coil wires connected backwards and Loose wire question

Post by waterdawg2004 » Wed Jun 22, 2016 11:51 am

This is how it looks now, runs better.
coil real small.jpg
coil real small.jpg (151.29 KiB) Viewed 8362 times

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: '79 Bus engine miss/ coil wires connected backwards and Loose wire question

Post by Amskeptic » Thu Jun 23, 2016 6:32 am

waterdawg2004 wrote:This is how it looks now, runs better.
coil real small.jpg
Heck yes. White wire is called "points signal" and it tells the ecu to fire the injectors each time the points close . . . or open, or I can't remember.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

Post Reply