Electrical cutoff switch & resistor question
04-05-2008, 01:02 AM
#16
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I worked with someone over on the 944 Challenge forum on one of these switches. Link is 944 Challenge
and wrote an article that is posted on the 944 Spec Website
944spec.org Tech Article
The longacre switch is set up for purpose built race cars with very limited wiring, not factory cars like ours.
and wrote an article that is posted on the 944 Spec Website
944spec.org Tech Article
The longacre switch is set up for purpose built race cars with very limited wiring, not factory cars like ours.
04-05-2008, 08:33 AM
#17
Burning Brakes
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Jim,
A quick look at one of the wiring diagrams shows it running into the central electric panel at connection D15, then back out at D44 and on up to the alarm unit. That doesn't make a whole lot of sense, but it didn't dig any further. I'll need to look at it a little closer.
It's the same on the 85.5 and the '92 968 diagrams, so it doesn't look like that was changed over the years. What year is you car?
I'll be tied up most of the day at an SCCA rallycross, but I'll have another look at it tonight.
BTW - that switch will be fine. It doesn't matter how many different circuits are in the car; it will kill them all.
A quick look at one of the wiring diagrams shows it running into the central electric panel at connection D15, then back out at D44 and on up to the alarm unit. That doesn't make a whole lot of sense, but it didn't dig any further. I'll need to look at it a little closer.
It's the same on the 85.5 and the '92 968 diagrams, so it doesn't look like that was changed over the years. What year is you car?
I'll be tied up most of the day at an SCCA rallycross, but I'll have another look at it tonight.
BTW - that switch will be fine. It doesn't matter how many different circuits are in the car; it will kill them all.
04-05-2008, 09:53 AM
#18
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Thread Starter
I worked with someone over on the 944 Challenge forum on one of these switches. Link is 944 Challenge
and wrote an article that is posted on the 944 Spec Website
944spec.org Tech Article
The longacre switch is set up for purpose built race cars with very limited wiring, not factory cars like ours.
and wrote an article that is posted on the 944 Spec Website
944spec.org Tech Article
The longacre switch is set up for purpose built race cars with very limited wiring, not factory cars like ours.
Jim,
A quick look at one of the wiring diagrams shows it running into the central electric panel at connection D15, then back out at D44 and on up to the alarm unit. That doesn't make a whole lot of sense, but it didn't dig any further. I'll need to look at it a little closer.
It's the same on the 85.5 and the '92 968 diagrams, so it doesn't look like that was changed over the years. What year is you car?
I'll be tied up most of the day at an SCCA rallycross, but I'll have another look at it tonight.
BTW - that switch will be fine. It doesn't matter how many different circuits are in the car; it will kill them all.
A quick look at one of the wiring diagrams shows it running into the central electric panel at connection D15, then back out at D44 and on up to the alarm unit. That doesn't make a whole lot of sense, but it didn't dig any further. I'll need to look at it a little closer.
It's the same on the 85.5 and the '92 968 diagrams, so it doesn't look like that was changed over the years. What year is you car?
I'll be tied up most of the day at an SCCA rallycross, but I'll have another look at it tonight.
BTW - that switch will be fine. It doesn't matter how many different circuits are in the car; it will kill them all.
Everything else seems to make sense to me now. Once I get confirmation on what to do with the smaller of the two alternator wires I will dig in. Thanks again for all the help!!!
04-05-2008, 09:56 AM
#19
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Thread Starter
Where does the "Field wire" (I'm assuming this is the alternator exciter wire) on our cars connect to? I imagine you're fine to "break" the main power lead to the (+) terminal of the battery, and the exciter wire to the alternator.... but if you know where the other end of the alternator exciter wire is, this could make wiring a bit easier.
I'll get caught up eventually Scott
04-05-2008, 11:09 AM
#20
Jim,
A quick look at one of the wiring diagrams shows it running into the central electric panel at connection D15, then back out at D44 and on up to the alarm unit. That doesn't make a whole lot of sense, but it didn't dig any further. I'll need to look at it a little closer.
A quick look at one of the wiring diagrams shows it running into the central electric panel at connection D15, then back out at D44 and on up to the alarm unit. That doesn't make a whole lot of sense, but it didn't dig any further. I'll need to look at it a little closer.
That wiring can be simplified by simply taking it off the back of the alternator, and connecting it to the bulb at the cluster, through a small fuse.
04-05-2008, 11:48 AM
#21
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Jerry, thanks for those links. However, John's procedure using the Longacre diagram seems to make sense to me. Both ways would probably work just fine. My car's wiring has been simplified when I deleted most interior wiring, headlights, windshield wipers, squirts, brake sensors, turn signals, horns, etc... Basically all that's left is what is needed to make the car run.
04-05-2008, 01:08 PM
#22
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04-05-2008, 01:33 PM
#23
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04-05-2008, 06:19 PM
#24
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This switch will only be used if I have a serious incident or if a race steward decides to test it. If it is used extremely rarely is there still a risk of alternator damage? Or is damage something that would happen due to frequent use?
Why is the alternator power wire routed through the starter to the battery instead of directly to the battery (from the factory)? Just trying to understand the system.
Why is the alternator power wire routed through the starter to the battery instead of directly to the battery (from the factory)? Just trying to understand the system.
04-06-2008, 11:17 AM
#25
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Well I certainly like the idea of not frying my alternator, so I assume this is a better switch to use?
http://www.ogracing.com/catalog/2-Ca...OLE-KILLSWITCH
If so, then is this the correct wiring?
http://www.ogracing.com/catalog/2-Ca...OLE-KILLSWITCH
If so, then is this the correct wiring?
04-06-2008, 01:20 PM
#26
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Jim,
That is the correct wiring for the OG style switch. Just use a meter to check which pair of the small terminals is which . With the switch on (run position) 1 pair is closed and the other open. When the switch is used (stop position) they switch over.
Feel free to PM me if you have more questions
That is the correct wiring for the OG style switch. Just use a meter to check which pair of the small terminals is which . With the switch on (run position) 1 pair is closed and the other open. When the switch is used (stop position) they switch over.
Feel free to PM me if you have more questions
04-06-2008, 01:30 PM
#27
Herr Unmöglich
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Dammit Jim! Don't feel bad.
I was staring at this thread and my car yesterday. I have the same 4 pole Longacre you do and was trying to lay out cable to hook it up. Guess it will have to wait til NEXT weekend after I too order a 6 pole.
I was staring at this thread and my car yesterday. I have the same 4 pole Longacre you do and was trying to lay out cable to hook it up. Guess it will have to wait til NEXT weekend after I too order a 6 pole.
04-06-2008, 04:12 PM
#28
Jim,
A quick look at one of the wiring diagrams shows it running into the central electric panel at connection D15, then back out at D44 and on up to the alarm unit. That doesn't make a whole lot of sense, but it didn't dig any further. I'll need to look at it a little closer.
A quick look at one of the wiring diagrams shows it running into the central electric panel at connection D15, then back out at D44 and on up to the alarm unit. That doesn't make a whole lot of sense, but it didn't dig any further. I'll need to look at it a little closer.
The wire starts life at the cluster, there it is red/yellow and works it's way to the factory alarm. In the factory alarm plug you'll find the red/yellow wire right next to the blue alternator exciter wire. It completes it's path through the alarm, possibly a method of checking ignition status.
I simply cut the red/yellow and blue wire at the alarm plug, and patched them together outside of the alarm.
This wiring was verified with a volt/ohm meter.
04-06-2008, 07:57 PM
#29
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Thread Starter
Jim,
That is the correct wiring for the OG style switch. Just use a meter to check which pair of the small terminals is which . With the switch on (run position) 1 pair is closed and the other open. When the switch is used (stop position) they switch over.
Feel free to PM me if you have more questions
That is the correct wiring for the OG style switch. Just use a meter to check which pair of the small terminals is which . With the switch on (run position) 1 pair is closed and the other open. When the switch is used (stop position) they switch over.
Feel free to PM me if you have more questions
I just traced the route of the alternator exciter wire, here is my finding.
The wire starts life at the cluster, there it is red/yellow and works it's way to the factory alarm. In the factory alarm plug you'll find the red/yellow wire right next to the blue alternator exciter wire. It completes it's path through the alarm, possibly a method of checking ignition status.
I simply cut the red/yellow and blue wire at the alarm plug, and patched them together outside of the alarm.
This wiring was verified with a volt/ohm meter.
The wire starts life at the cluster, there it is red/yellow and works it's way to the factory alarm. In the factory alarm plug you'll find the red/yellow wire right next to the blue alternator exciter wire. It completes it's path through the alarm, possibly a method of checking ignition status.
I simply cut the red/yellow and blue wire at the alarm plug, and patched them together outside of the alarm.
This wiring was verified with a volt/ohm meter.
The nice thing about using a 6-pole switch is that the wiring seems much more simple. No messing with the alternator or starter, and everything that needs to be wired/rewired is in the engine bay and easily accessible.
04-06-2008, 08:12 PM
#30
Campeck Rulez
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well damnit. I just bought a single pole switch from auto-zone to use in the roadster. But it looks like by rewading this that hooking all the positive cables through the switch wont do anything cause the alternator will keep the car running?
or it will surge and blow fuses? So If my car is running and I unplug the positive on my battery what will happen...(before I go actually do it)
or it will surge and blow fuses? So If my car is running and I unplug the positive on my battery what will happen...(before I go actually do it)