Strange ABS issue on 964 RSR
08-17-2005, 12:54 PM
#16
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Originally Posted by jrotsaert
Thanks Adrian. WIll try that- I do have the cut-off switch installed (big ugly red thing on the right of the dashboard).
Those who want pics, e-mail me, I have a few nice ones static and dynamic at various tracks- Brands Hatch, SPa, Castle Combe and Silverstone
JM
Those who want pics, e-mail me, I have a few nice ones static and dynamic at various tracks- Brands Hatch, SPa, Castle Combe and Silverstone
JM
As you brake the engine rpm dips. The alternator/voltage regulator may well be for some reason not able to keep up the battery charge. You should have a very small battery fitted so the voltage may drop to the ABS low cutoff point.
I read the previous posting and you seemed to get nowhere.
I am not going to speculate due to lack of exact knowledgeof theinternal workings of the racing ABS.
All I can do is just advise that the basics be carried out first.
I helped somebody yesterday with a problem which was seriously weird. It turned out to be the type of battery he had just installed.
The battery terminals were the incorrect shape and the connectors could not be tightened correctly. Did horrible things including setting the alarm off intermittantly. Was on a 993 but the same applies to the 964 in this area.
Ciao,
Adrian.
08-17-2005, 03:26 PM
#17
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Originally Posted by Adrian
I am sure the racing ABS is fitted with undervoltage protection. Have you checked the alternator/battery system?
As you brake the engine rpm dips. The alternator/voltage regulator may well be for some reason not able to keep up the battery charge. You should have a very small battery fitted so the voltage may drop to the ABS low cutoff point.
I read the previous posting and you seemed to get nowhere.
I am not going to speculate due to lack of exact knowledgeof theinternal workings of the racing ABS.
All I can do is just advise that the basics be carried out first.
I helped somebody yesterday with a problem which was seriously weird. It turned out to be the type of battery he had just installed.
The battery terminals were the incorrect shape and the connectors could not be tightened correctly. Did horrible things including setting the alarm off intermittantly. Was on a 993 but the same applies to the 964 in this area.
Ciao,
Adrian.
As you brake the engine rpm dips. The alternator/voltage regulator may well be for some reason not able to keep up the battery charge. You should have a very small battery fitted so the voltage may drop to the ABS low cutoff point.
I read the previous posting and you seemed to get nowhere.
I am not going to speculate due to lack of exact knowledgeof theinternal workings of the racing ABS.
All I can do is just advise that the basics be carried out first.
I helped somebody yesterday with a problem which was seriously weird. It turned out to be the type of battery he had just installed.
The battery terminals were the incorrect shape and the connectors could not be tightened correctly. Did horrible things including setting the alarm off intermittantly. Was on a 993 but the same applies to the 964 in this area.
Ciao,
Adrian.
Your wisdom is very much appreciated. I doubt that it's the battery as it's not only related to braking, it also happened in the paddock, passing a really big bump.The mechanic has the car and I've passed all I could find onto him. I should get the car back in a few days... racing at Brands in Enduro in 2 weeks. Can't wait!
JM
08-17-2005, 07:47 PM
#19
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something similar happened to me.
if your RSR is like the cup - the master kill switch is located directly above the battery - if your battery hold downs are loose at all (and i mean even just a little) it could cause the negative terminal to either touch or get close enough to arc the positive terminals on the bottom of the kill switch.
My symptoms were the car it'sself cutting out for very brief intervels under hard braking or when hitting a bump. This caused the lights on the dash to light up.
These are not your exact symptoms i know but it is something to check as well.
the second culprit is the ABS kill switch (replace with 964.616.135.70 Bosch switch) or the Kill switch harness wiring into the central electrics - this could have come loose or is grounding out.
i have a pretty bad scan of the diagram at http://www.carreracupusa.org/Race/el...electrical.htm
Hope that helps
if your RSR is like the cup - the master kill switch is located directly above the battery - if your battery hold downs are loose at all (and i mean even just a little) it could cause the negative terminal to either touch or get close enough to arc the positive terminals on the bottom of the kill switch.
My symptoms were the car it'sself cutting out for very brief intervels under hard braking or when hitting a bump. This caused the lights on the dash to light up.
These are not your exact symptoms i know but it is something to check as well.
the second culprit is the ABS kill switch (replace with 964.616.135.70 Bosch switch) or the Kill switch harness wiring into the central electrics - this could have come loose or is grounding out.
i have a pretty bad scan of the diagram at http://www.carreracupusa.org/Race/el...electrical.htm
Hope that helps
08-18-2005, 07:29 PM
#20
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Thread Starter
Originally Posted by Cupcar#12
something similar happened to me.
if your RSR is like the cup - the master kill switch is located directly above the battery - if your battery hold downs are loose at all (and i mean even just a little) it could cause the negative terminal to either touch or get close enough to arc the positive terminals on the bottom of the kill switch.
My symptoms were the car it'sself cutting out for very brief intervels under hard braking or when hitting a bump. This caused the lights on the dash to light up.
These are not your exact symptoms i know but it is something to check as well.
the second culprit is the ABS kill switch (replace with 964.616.135.70 Bosch switch) or the Kill switch harness wiring into the central electrics - this could have come loose or is grounding out.
i have a pretty bad scan of the diagram at http://www.carreracupusa.org/Race/el...electrical.htm
Hope that helps
if your RSR is like the cup - the master kill switch is located directly above the battery - if your battery hold downs are loose at all (and i mean even just a little) it could cause the negative terminal to either touch or get close enough to arc the positive terminals on the bottom of the kill switch.
My symptoms were the car it'sself cutting out for very brief intervels under hard braking or when hitting a bump. This caused the lights on the dash to light up.
These are not your exact symptoms i know but it is something to check as well.
the second culprit is the ABS kill switch (replace with 964.616.135.70 Bosch switch) or the Kill switch harness wiring into the central electrics - this could have come loose or is grounding out.
i have a pretty bad scan of the diagram at http://www.carreracupusa.org/Race/el...electrical.htm
Hope that helps
JM
