Need Info: 82 Euro S specific fuse/relay chart
01-10-2011, 02:30 AM
#47
Rennlist Member
Last edited by gbgastowers; 01-10-2011 at 02:42 AM. Reason: added
01-10-2011, 02:43 AM
#50
Rennlist Member
It sounds like it might be an earlier 82 and so had the earlier wiring. A good start would be to replace the ignition switch because I'll bet the contacts on that are welded together, then update to the later circuit so that the switch only carries the relay coil current.
I can't believe that someone could design a circuit where a relay is used to switch a load, but the load is also fed through contacts on the switch. The point of using a relay is to save switches from frying contacts as a result of carrying the full circuit load, shorten primary circuit lengths and avoid voltage drop ... wtf were they thinking with the original circuit?
I can't believe that someone could design a circuit where a relay is used to switch a load, but the load is also fed through contacts on the switch. The point of using a relay is to save switches from frying contacts as a result of carrying the full circuit load, shorten primary circuit lengths and avoid voltage drop ... wtf were they thinking with the original circuit?
01-10-2011, 03:36 AM
#54
Nordschleife Master
Yes it is.
There is no safety lockout on 5-speed 928's. You can start the car in gear and in neutral. Be very careful of this and don't crush yourself against your garage wall.
When I had a clutch failure, I drove home - at stop lights, I just stalled it and waited out the red light, then used first gear and the starter motor to get moving again. Even worked up a slight incline
PS - awesome save Gunar. Your pelican thread is one of the few I bother reading over there lately.
There is no safety lockout on 5-speed 928's. You can start the car in gear and in neutral. Be very careful of this and don't crush yourself against your garage wall.
When I had a clutch failure, I drove home - at stop lights, I just stalled it and waited out the red light, then used first gear and the starter motor to get moving again. Even worked up a slight incline
PS - awesome save Gunar. Your pelican thread is one of the few I bother reading over there lately.
01-10-2011, 01:12 PM
#55
Rennlist Member
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Dave Taz was right - I should have done more research! Let's see if we can make sense of the start relay mess...
The power to trigger the starter solenoid starts at the ignition switch, and the bus (circuit) is called "50", and uses yellow wires. After that power leaves the Central Electric Panel, AFAIK all cars are the same - the power goes thru Pin 1 on the corner of the 14-pin connector near the jump start terminal and then goes to the operating terminal of the solenoid. What we need to discuss is what happens in the Central Electric Panel.
The socket appears to be the same for all cars - the socket uses the standard "53" or "24" SPST (Single Pole Single Throw) relay. The terminals in the socket and the pins on the relay are identified as 30, 85, 86, and 87.
85 and 86 are the connections for the operating coil of the relay. When you apply power to one side, and ground(earth) to the other side, the relay closes the SPST switch. The circuit that applies the power to the coil obviously varies with different model years. The circuit that applies the ground to the coil obviously varies with different model years.
30 is usually power in, and may be from the 30 bus, which is unswitched battery power, or may be from the 15 bus, which is ignition-switched power, or may be from some other source.
In the starter activation circuit, this source obviously varies for different model years.
The 87 terminal is the load terminal, and it appears that this terminal is connected to the starter solenoid in all model years.
It appears that the possible circuits include:
- The 50 bus may be connected to the 30 terminal, the 15 bus to the 86 terminal, the 85 terminal to the neutral safety switch, and the 87 terminal to the starter solenoid. When the ignition switch is on, the coil has power. If the transmission is in neutral or park, the relay operates, closing the relay contacts. When the ignition switch is turned to the start position, power is applied to the 30 terminal, flows thru the contacts, and triggers the starter. If the transmission is not in neutral or park, the relay does not operate, and the starter does not operate. If you install a bridge or jumper in this circuit, it must be between 30 and 87. This circuit was apparently used in some of the early cars. It does not strictly meet DIN standards, and I am surprised the Porsche did it this way. The confusion that we have is an obvious result. Any mechanic who is experienced with German cars would expect the 30 terminal to have battery power or ignition-switched power, not the 50 bus.
- The 30 terminal may be connected to the 30 bus, and always have battery power. The 87 terminal will be connected to the starter solenoid. The 86 terminal is connected to the ignition start position thru the 50 bus. The 85 terminal will be connected to either the transmission neutral safety switch on the automatic transmission or to a hard ground on the five-speed models. This appears to be the circuit used on all later models (apparently starting sometime in 1982, with some possible exceptions). A bridge is not used in this circuit, and if a bridge or jumper is connected between 30 and 87, the starter will immediately operate. If you need to install an emergency jumper (if the neutral safety switch is not functioning, for example), it should be installed between 86 and 87.
As a side note, you can separate the 14-pin connector and insert a short piece of stranded wire in the socket for Pin 1 (yellow wire), then reconnect the plug leaving the short wire sticking out. If you then touch the short wire to the jump start terminal, the starter will spin. If your car is a five-speed and is in gear, it will run over your right foot. This kludge can be useful if you are having problems getting the starter to operate while you are on the road, or if you want to use a remote start switch while doing a compression test.
The power to trigger the starter solenoid starts at the ignition switch, and the bus (circuit) is called "50", and uses yellow wires. After that power leaves the Central Electric Panel, AFAIK all cars are the same - the power goes thru Pin 1 on the corner of the 14-pin connector near the jump start terminal and then goes to the operating terminal of the solenoid. What we need to discuss is what happens in the Central Electric Panel.
The socket appears to be the same for all cars - the socket uses the standard "53" or "24" SPST (Single Pole Single Throw) relay. The terminals in the socket and the pins on the relay are identified as 30, 85, 86, and 87.
85 and 86 are the connections for the operating coil of the relay. When you apply power to one side, and ground(earth) to the other side, the relay closes the SPST switch. The circuit that applies the power to the coil obviously varies with different model years. The circuit that applies the ground to the coil obviously varies with different model years.
30 is usually power in, and may be from the 30 bus, which is unswitched battery power, or may be from the 15 bus, which is ignition-switched power, or may be from some other source.
In the starter activation circuit, this source obviously varies for different model years.
The 87 terminal is the load terminal, and it appears that this terminal is connected to the starter solenoid in all model years.
It appears that the possible circuits include:
- The 50 bus may be connected to the 30 terminal, the 15 bus to the 86 terminal, the 85 terminal to the neutral safety switch, and the 87 terminal to the starter solenoid. When the ignition switch is on, the coil has power. If the transmission is in neutral or park, the relay operates, closing the relay contacts. When the ignition switch is turned to the start position, power is applied to the 30 terminal, flows thru the contacts, and triggers the starter. If the transmission is not in neutral or park, the relay does not operate, and the starter does not operate. If you install a bridge or jumper in this circuit, it must be between 30 and 87. This circuit was apparently used in some of the early cars. It does not strictly meet DIN standards, and I am surprised the Porsche did it this way. The confusion that we have is an obvious result. Any mechanic who is experienced with German cars would expect the 30 terminal to have battery power or ignition-switched power, not the 50 bus.
- The 30 terminal may be connected to the 30 bus, and always have battery power. The 87 terminal will be connected to the starter solenoid. The 86 terminal is connected to the ignition start position thru the 50 bus. The 85 terminal will be connected to either the transmission neutral safety switch on the automatic transmission or to a hard ground on the five-speed models. This appears to be the circuit used on all later models (apparently starting sometime in 1982, with some possible exceptions). A bridge is not used in this circuit, and if a bridge or jumper is connected between 30 and 87, the starter will immediately operate. If you need to install an emergency jumper (if the neutral safety switch is not functioning, for example), it should be installed between 86 and 87.
As a side note, you can separate the 14-pin connector and insert a short piece of stranded wire in the socket for Pin 1 (yellow wire), then reconnect the plug leaving the short wire sticking out. If you then touch the short wire to the jump start terminal, the starter will spin. If your car is a five-speed and is in gear, it will run over your right foot. This kludge can be useful if you are having problems getting the starter to operate while you are on the road, or if you want to use a remote start switch while doing a compression test.
01-11-2011, 05:46 AM
#56
Rennlist Member
Thread Starter
Thanks for that explanation, Wally!
Here's a another shred of information about 82 panel ( "05" ) from electrical training documents.
Leads me to believe all 82 might utilize relay, not just automatics.
(Note that ROW and USA PET both list some sort of "bridge" for 82 manual cars using the ".05" panel. It is a different part number than 81 bridge however.)
Even though that "82 bridge" is listed in the CE Panel section of the PET, I"d bet its really a short wire --- for use under the hatch, for bridging the connector that normally attaches to the automatic transmission start interlock switch.
So, 82 manual has a relay. And a bridge. Bridge is in hatch area. Gunar, check under your spare tire for a white plastic connector with a little short wire bridge linking two terminals. I have it on the 84 manual cars here, you probably do too on the 82.
Here's a another shred of information about 82 panel ( "05" ) from electrical training documents.
Leads me to believe all 82 might utilize relay, not just automatics.
(Note that ROW and USA PET both list some sort of "bridge" for 82 manual cars using the ".05" panel. It is a different part number than 81 bridge however.)
Even though that "82 bridge" is listed in the CE Panel section of the PET, I"d bet its really a short wire --- for use under the hatch, for bridging the connector that normally attaches to the automatic transmission start interlock switch.
So, 82 manual has a relay. And a bridge. Bridge is in hatch area. Gunar, check under your spare tire for a white plastic connector with a little short wire bridge linking two terminals. I have it on the 84 manual cars here, you probably do too on the 82.
Last edited by Landseer; 06-22-2011 at 03:22 PM.
