No Ground Strap?!
07-07-2009 | 01:31 PM
#46
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Joined: Jun 2001
Posts: 6,469
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From: Acworth, GA
The charging circuit is shown on Pages 97-31 and 97-45 of the Factory Workshop Manual Wiring Diagrams:
The gray area at the top of the page is the Central Electric Panel.
- All lines represent the wires behind the Panel. Connected wires are shown by dots where they cross.
- The Roman numerals show the relay positions. These are identified on the panel, but you will need a flashlight to read them. Go to our web site. Click to enter. Click on the + by 928 Fuse/Relay Charts. Click on 77-79. You will find a diagram of the Relays and the Fuses.
- The relay diagrams show the terminal numbers (which are standardized), and the basic mechanism inside the relay.
The numbers at the bottom of the gray area show the Plug terminal connections. The plugs are NOT shown on our relay charts. The plugs are lettered left to right, starting with A on the left end. There is no I (i) plug. The shorter plugs in the center are out of sequence - they are Y and Z. The terminals on each plug are arranged:
4 8
3 7
2 6
1 5
Therefore, "E6" is the next-to-bottom terminal on the right side of the 5th plug from the left end.
The wiring in the car is shown by solid or dashed lines. The solid lines indicate a solid color - for example all unswitched ground wires are solid brown. All switched ground wires are dashed, and indicate a brown wire with a colored stripe. Other dashed wires are different base colors with a thin stripe of a different color. For example, the wire that supplies power to the turn signal flasher is a dashed line marked "bk/ye", showing a black wire with a yellow stripe.
The gray boxes in the main field are devices in the car, such as the emergency flasher switch. The numbers around the box show the connecting terminals (again, the same standardized numbers).
The small boxes with Roman numbers/Arabic numbers show a circuit jump to a different area of the diagram. For example, there are several such boxes connected to the emergency flasher switch. One such box is marked "IX/1". This means that the brown wire leading to the box continues on Part IX in area 1. The areas are the numbers at the bottom of the page. The box that we are discussing is located at III/20. You will go to Part IX, which is on Page 97-47, look in area 1 and find a brown wire. This show the continuation of the circuit.
The line at the bottom of the page shows chassis ground. The numbers in circles are the major ground points, where you will find several brown wires connected to the body or the engine.
The power to excite the alternator has an elaborate route.
1) Battery to ignition switch. (97-31)
2) Ignition switch to bus 15 (general switched power bus). (97-31)
3) Bus 15 to terminal H7 on the central power panel. (Connectors are A-Z, left to right on the bottom of the panel). (97-45)
4) H7 on a black wire to terminal 1R on the instrument pod. (97-45)
5) Terminal 1R to the Generator light, and to a resistor mounted in parallel to the light. If the light is burned out, the alternator won't receive enough power to generate. Bad connection or bulb in the pod is a likely problem. (97-45)
6) From the light/resistor to terminal 2R in the pod. (97-45)
7) Terminal 2R on a blue wire to terminal H8 on the central power panel. There are two blue wires here - power goes to the central warning computer, and to H8. (97-45)
8)Terminal H8 to terminal Z6. (97-31)
9) Terminal Z6 outside on a black wire to terminal Z1. (97-31)
10) Terminal Z1 inside to terminal O8. (97-31)
11) Terminal O8 on a blue wire to the alternator. (97-31)
While there are numerous possible failure points in this circuit, some of the more common include:
- Burned out charge light bulb.
- Failed parallel resistor (back of the voltage gauge).
- Bad connection in the 14-pin connector located in the engine compartment on the right fender liner, just under the jump start terminal. Be careful - this connector can fall apart while you are cleaning it!
If you do not have the Factory Workshop Manuals, I would strongly suggest that you contact Jim Morehouse and get the 928 tech info CD set that he has prepared. These CDs contain a HUGE amount of 928 tech info, including the manuals with wiring diagrams. Jim's email address is jim928ATptd.net - change AT to @
The gray area at the top of the page is the Central Electric Panel.
- All lines represent the wires behind the Panel. Connected wires are shown by dots where they cross.
- The Roman numerals show the relay positions. These are identified on the panel, but you will need a flashlight to read them. Go to our web site. Click to enter. Click on the + by 928 Fuse/Relay Charts. Click on 77-79. You will find a diagram of the Relays and the Fuses.
- The relay diagrams show the terminal numbers (which are standardized), and the basic mechanism inside the relay.
The numbers at the bottom of the gray area show the Plug terminal connections. The plugs are NOT shown on our relay charts. The plugs are lettered left to right, starting with A on the left end. There is no I (i) plug. The shorter plugs in the center are out of sequence - they are Y and Z. The terminals on each plug are arranged:
4 8
3 7
2 6
1 5
Therefore, "E6" is the next-to-bottom terminal on the right side of the 5th plug from the left end.
The wiring in the car is shown by solid or dashed lines. The solid lines indicate a solid color - for example all unswitched ground wires are solid brown. All switched ground wires are dashed, and indicate a brown wire with a colored stripe. Other dashed wires are different base colors with a thin stripe of a different color. For example, the wire that supplies power to the turn signal flasher is a dashed line marked "bk/ye", showing a black wire with a yellow stripe.
The gray boxes in the main field are devices in the car, such as the emergency flasher switch. The numbers around the box show the connecting terminals (again, the same standardized numbers).
The small boxes with Roman numbers/Arabic numbers show a circuit jump to a different area of the diagram. For example, there are several such boxes connected to the emergency flasher switch. One such box is marked "IX/1". This means that the brown wire leading to the box continues on Part IX in area 1. The areas are the numbers at the bottom of the page. The box that we are discussing is located at III/20. You will go to Part IX, which is on Page 97-47, look in area 1 and find a brown wire. This show the continuation of the circuit.
The line at the bottom of the page shows chassis ground. The numbers in circles are the major ground points, where you will find several brown wires connected to the body or the engine.
The power to excite the alternator has an elaborate route.
1) Battery to ignition switch. (97-31)
2) Ignition switch to bus 15 (general switched power bus). (97-31)
3) Bus 15 to terminal H7 on the central power panel. (Connectors are A-Z, left to right on the bottom of the panel). (97-45)
4) H7 on a black wire to terminal 1R on the instrument pod. (97-45)
5) Terminal 1R to the Generator light, and to a resistor mounted in parallel to the light. If the light is burned out, the alternator won't receive enough power to generate. Bad connection or bulb in the pod is a likely problem. (97-45)
6) From the light/resistor to terminal 2R in the pod. (97-45)
7) Terminal 2R on a blue wire to terminal H8 on the central power panel. There are two blue wires here - power goes to the central warning computer, and to H8. (97-45)
8)Terminal H8 to terminal Z6. (97-31)
9) Terminal Z6 outside on a black wire to terminal Z1. (97-31)
10) Terminal Z1 inside to terminal O8. (97-31)
11) Terminal O8 on a blue wire to the alternator. (97-31)
While there are numerous possible failure points in this circuit, some of the more common include:
- Burned out charge light bulb.
- Failed parallel resistor (back of the voltage gauge).
- Bad connection in the 14-pin connector located in the engine compartment on the right fender liner, just under the jump start terminal. Be careful - this connector can fall apart while you are cleaning it!
If you do not have the Factory Workshop Manuals, I would strongly suggest that you contact Jim Morehouse and get the 928 tech info CD set that he has prepared. These CDs contain a HUGE amount of 928 tech info, including the manuals with wiring diagrams. Jim's email address is jim928ATptd.net - change AT to @
07-07-2009 | 02:06 PM
#47
Thread Starter
Instructor
Joined: Jan 2009
Posts: 128
Likes: 0
From: Lake Placid, FL
Thanks a lot Wally, I was confused as to how they were all labeled, also learning how to read the wiring diagrams now-I downloaded and saved the workshop manuals and wiring diagrams from a website connell.uk I think.
I found o8 and tested with ignition on, there was no voltage so as Alan stated I need to work on my pod connections, which are what I was referring to Landseer, if your wondering. The wiring harness part seems good, its the connection to the circuit board that is in bad shape, I will try tightening up the connection today some how.
I found o8 and tested with ignition on, there was no voltage so as Alan stated I need to work on my pod connections, which are what I was referring to Landseer, if your wondering. The wiring harness part seems good, its the connection to the circuit board that is in bad shape, I will try tightening up the connection today some how.
07-07-2009 | 02:54 PM
#48
Thread Starter
Instructor
Joined: Jan 2009
Posts: 128
Likes: 0
From: Lake Placid, FL
OK, I tested for continuity from o8 to the lower screw holding in the resistor since I have my pod slid forward about 6in. There was continuity which means that the connector is OK behind the dash pod since that would have to bridge the gap across the connector, right? Also, I don't know if this says anything but there was also continuity from the first screw holding in the resistor over to the second which means the resistor is OK, or is it more complicated than that?
07-07-2009 | 03:43 PM
#49
Thread Starter
Instructor
Joined: Jan 2009
Posts: 128
Likes: 0
From: Lake Placid, FL
Mike(Firemed) stopped by today and took a look. Basically it was the connection behind the dash that was the problem, since the printed circuit board was a mess we decided to just order a new one from 928 intl. Once its here (2 days) I will install it and everything should work.
07-07-2009 | 06:55 PM
#50
Three Wheelin'
Joined: Dec 2005
Posts: 1,822
Likes: 1
From: In the boatyard installing the mast and engine, we don't need a crane, we harness the mesquito's! Yeah!
Yep - Well, it has been said that connecting the instrument panel to the rest of the car helps a few functions, non the less charging...
A big Thank you to Tom at 928 International for having parts in stock and ready to ship on a seconds notice.
And BTW Kyle...
The rest of the guys would drool over the car - she is beautiful! - I'll bet they would love it if you would post some pics when you have her running!
A big Thank you to Tom at 928 International for having parts in stock and ready to ship on a seconds notice.
And BTW Kyle...
The rest of the guys would drool over the car - she is beautiful! - I'll bet they would love it if you would post some pics when you have her running!
