clutch switch problems
05-19-03, 03:16 PM
#1
FD > FB > FC
Thread Starter
clutch switch problems
Well I was working on my wiring for my motor swap today, armed with a test light and voltmeter.
I had to bridge the connection from the fb harness to the fc one right at the ecu connection. Heres the problem.
I cant get any signal from my clutch switch. My car was origionally an automatic so the connector for it was tied back in the harness but I have doublechecked that it is the right connector.
I made sure I had a good ground for the test light and voltmeter. The only thing that I can think of is that I cannot start the car yet, I can only bring the ignition switch to the on position.
Any ideas on what the problem is?
I had to bridge the connection from the fb harness to the fc one right at the ecu connection. Heres the problem.
I cant get any signal from my clutch switch. My car was origionally an automatic so the connector for it was tied back in the harness but I have doublechecked that it is the right connector.
I made sure I had a good ground for the test light and voltmeter. The only thing that I can think of is that I cannot start the car yet, I can only bring the ignition switch to the on position.
Any ideas on what the problem is?
05-19-03, 03:40 PM
#2
Got Boost?
IIRC the positive voltage signal that the clutch switch sees comes from the ecu. essentially the switch is pull-down, it is ment to pull the signal sent to it from its positive voltage to ground. So technically you shouldn't see a signal when pushed. There could be a number of issues: First, you don't have your old ecu connectted, right..... you may need to convert this over too the new ecu's connector some how. Second, if you already have that done, its possible that the ecu only sends a signal to the switch when its attempting to check its state.
In any case, the thing that will elliminate all doubt is testing it with a ohmmeter. If the switch doesn't switch from 'infinite' resistance to 'zero' (note: there is no such thing as truely infinite resistance and with few exceptions, zero either) when the pedal is pushed, you have a problem with the switch, else the problem is upstream.
Good luck, I've been going through my entire wiring harness from the radiator to the rear bumper, and taking out unneeded connectors, wires and the like in anticipation of the Haltech E6K going in (That and I have the urge to "simplify and lighten"). So I know how you probably feel.
In any case, the thing that will elliminate all doubt is testing it with a ohmmeter. If the switch doesn't switch from 'infinite' resistance to 'zero' (note: there is no such thing as truely infinite resistance and with few exceptions, zero either) when the pedal is pushed, you have a problem with the switch, else the problem is upstream.
Good luck, I've been going through my entire wiring harness from the radiator to the rear bumper, and taking out unneeded connectors, wires and the like in anticipation of the Haltech E6K going in (That and I have the urge to "simplify and lighten"). So I know how you probably feel.
05-19-03, 05:31 PM
#3
FD > FB > FC
Thread Starter
That may be it, in fact it probably is, BUT the wiring diagram shows it as an input signal...
So shouldnt the voltage go into the ECU rather than outward?
I'm not using my old ecu though, theres no point! LOL. But what you said about the clutch switch makes sence. I guess I'll know when I turn the key and hear cranking or a click or neither.
So shouldnt the voltage go into the ECU rather than outward?
I'm not using my old ecu though, theres no point! LOL. But what you said about the clutch switch makes sence. I guess I'll know when I turn the key and hear cranking or a click or neither.
Last edited by hornbm; 05-19-03 at 05:33 PM.
05-19-03, 09:24 PM
#4
RX-7 Alumni
hornbm,
edit: Whoops, I didn't see till later that you have an S5, all this is for an S4. Anyway use the built in self checker, that might help.
First, I'm doing the same project and according to the FB and FC schematics the clutch switch wiring is exactly the same setup. I plan on switching the pins out of the FB connector to the FC connector in the correct location. That's if the pins are the same, let me know if I'm wrong on that.
Basically the clutch switch should have below 1.5v on the ECU side and 12v on the other when the switch is open. When the switch is depressed, both sides should have 12v, all referenced to ground. You should be able to disconnect the ECU, put the ignition switch on (not start), and check the pin going to the ECU (L on the F-31 connector of the TII) to make sure it has 12v. Or maybe push your probe in the back of the connector and check it while the ECU is installed.
I'm going to build up an ECU self checker to read out codes. And instead of running the wires back up through the front harness, install the two diodes somewhere on the instrument cluster. Should be able to get instant ECU diagnostics all the time.
Here's a link to the DIY self checker and codes.
http://home.rmci.net/panther/86_88ecu.htm
I know I've seen another site on how to build it but in any event it is very easy and worth your trouble.
Good Luck with the Turbo FB and please let me know if them pins are the same.
Scott
edit: Whoops, I didn't see till later that you have an S5, all this is for an S4. Anyway use the built in self checker, that might help.
First, I'm doing the same project and according to the FB and FC schematics the clutch switch wiring is exactly the same setup. I plan on switching the pins out of the FB connector to the FC connector in the correct location. That's if the pins are the same, let me know if I'm wrong on that.
Basically the clutch switch should have below 1.5v on the ECU side and 12v on the other when the switch is open. When the switch is depressed, both sides should have 12v, all referenced to ground. You should be able to disconnect the ECU, put the ignition switch on (not start), and check the pin going to the ECU (L on the F-31 connector of the TII) to make sure it has 12v. Or maybe push your probe in the back of the connector and check it while the ECU is installed.
I'm going to build up an ECU self checker to read out codes. And instead of running the wires back up through the front harness, install the two diodes somewhere on the instrument cluster. Should be able to get instant ECU diagnostics all the time.
Here's a link to the DIY self checker and codes.
http://home.rmci.net/panther/86_88ecu.htm
I know I've seen another site on how to build it but in any event it is very easy and worth your trouble.
Good Luck with the Turbo FB and please let me know if them pins are the same.
Scott
Last edited by Rex4Life; 05-19-03 at 09:39 PM.
05-19-03, 11:02 PM
#5
FD > FB > FC
Thread Starter
well basically what I did, is I took the wire than ran into the stock ecu for the clutch switch, cut it and attached it to the wire on the new 89 ecu.
However, Now matter how I check it I get 0 volts. This is with the car in the on position but the ecu connector is unplugged. It sounds like to me that the switch isnt getting any power.
The only other part of the wiring is the main relay. It has to be wired to the ignition swich right? What exactly turns the main relay on and off? I checked the diagram but I didnt see anything connecting the ignition switch to the main relay.
Theres probably the same setup with the GSL-SE main relay, so if anyone wants to chime in on that, please do.
However, Now matter how I check it I get 0 volts. This is with the car in the on position but the ecu connector is unplugged. It sounds like to me that the switch isnt getting any power.
The only other part of the wiring is the main relay. It has to be wired to the ignition swich right? What exactly turns the main relay on and off? I checked the diagram but I didnt see anything connecting the ignition switch to the main relay.
Theres probably the same setup with the GSL-SE main relay, so if anyone wants to chime in on that, please do.
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