Car has trouble staying on. When I turn key to III the car starts and I would have to hold it just to keep the car on, I could also press the gas and it would accelerate. Once I let go off the ignition the car shuts off. Any idea what it could be and if so how did you fix the issue?
NSX starting issue
- Thread starter Trilapino
- Start date
Ignition key replacement
Reading through the FAQs it seems as if my ignition key has failed. As a temporary fix I was thinking of squirting Chemtool contact cleaner into it, but I guess replacement is imminent. Couple of questions: Is the NSX Ignition Key assembly common to any other Acura/Honda model or are we in for...
www.nsxprime.com
@drew is correct, it is with >90% certainty a failing ignition switch. If you remove the switch from the back of the lock cylinder assembly you may be able to pull it apart and clean and rehabilitate it (or fix previous owner wiring bodges). However, they are not very expensive so replacement with new is easy to swallow
www.acurapartswarehouse.com
The NSX ignition switch is an NSX only child part so don't bother looking for other Honda sibling products which use the same switch.
Edit:
Some North American Acura vendors show the part as currently unavailable so you may need to check around. Amayama appears to have them in stock.
www.amayama.com
35130-SL0-003 - Acura Parts Warehouse
www.acurapartswarehouse.com
The NSX ignition switch is an NSX only child part so don't bother looking for other Honda sibling products which use the same switch.
Edit:
Some North American Acura vendors show the part as currently unavailable so you may need to check around. Amayama appears to have them in stock.
Honda 35130-SL0-003 (35130SL0003) SWITCH COMP., STEERING
Honda 35130-SL0-003 (35130SL0003) SWITCH COMP., STEERING. New & genuine Japanese car parts. Fast shipping. Low prices. Request a quote from Amayama Trading Co. online.
www.amayama.com
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Or if you're in a hurry, go with Mita. I just got one from them and it took about a week with standard shipping. https://www.mitamotorsports.com/product/ignition-switch/
Clean the big battery wire connectors at both ends.
You likely have have a high resistance short...12vdc but not a lot of current.
See if jumping the battery...at the engine compartment...with another car helps.
You likely have have a high resistance short...12vdc but not a lot of current.
See if jumping the battery...at the engine compartment...with another car helps.
docjohn is correct that on occasion the switches have been delivered in one of the operated position rather than the 0 position. However, most commonly this prevents them from being installed. That said, when you turn to III things like the radio and AC normally turn off so it does seem like you might have a position issue.
This is the switch contact list from the service manual
The sure fire way to find the '0' position is to use a continuity tester to check for switch open / closed indications between the pins on the switch pigtail. All of them should show open in the 0 position. If not, with a flat blade screwdriver turn the center white part (red arrow below) on the switch that fits onto the back of the lock cylinder so that all of the contacts show open.
That is the position that you should install the switch onto the back of the lock cylinder which should also be in the 0 position. By turning the center white part, you can confirm that all the contacts on the switch are operating correctly.
If that doesn't fix the problem something more nefarious is at play.
This is the switch contact list from the service manual
The sure fire way to find the '0' position is to use a continuity tester to check for switch open / closed indications between the pins on the switch pigtail. All of them should show open in the 0 position. If not, with a flat blade screwdriver turn the center white part (red arrow below) on the switch that fits onto the back of the lock cylinder so that all of the contacts show open.
That is the position that you should install the switch onto the back of the lock cylinder which should also be in the 0 position. By turning the center white part, you can confirm that all the contacts on the switch are operating correctly.
If that doesn't fix the problem something more nefarious is at play.
So clean the
i just checked and it’s sitting flush. I made sure the hole groove matched the fitting. Hmmm I’ll try to flip it around and see if that makes any difference. If that doesn’t work I’ll try jumping it. Thanks a lot!
If jumping it means a remote start switch to operate the starter motor I suggest that you don't do that. There is obviously a problem of some kind and if you get the motor to start you might find that you cannot shut the motor off if there is some weird kind of problem with the switch.
Do the continuity tests described in the service manual and confirm that the switch is in the 0 position and that the continuity tests values are correct for the I, II and III positions. If the switch tests out OK return it to the 0 position and install it. If the no-start remains then you have a new electrical problem some place else that has emerged since you replaced the switch.
- do you have or did you ever have an aftermarket security system? After market systems frequently tap into the circuits at the ignition switch harness and if poorly done the wiring might have come apart when you moved the wiring to replace the switch
- check the #29 50 A fuse. This might have blown.
- check the button for the clutch interlock switch. If this has fallen out it will definitely prevent starter operation.
You’re right I don’t want that to happen with no being able turn off motor. I’ll try to reposition the the switch to 0. It does have an aftermarket security and I might need to check the wiring on that taps into the switch wiring. It was a bad job whoever did it. I’ll check fuse too. Where is that button for the clutch interlock switch?
Aftermarket security system = evil! If you had noted that at the start that would have been tops on my list for things to check before fast tracking to replacing the ignition switch. If confirming the position of the ignition switch at 0 does not fix the problem I would start looking for dodgy wiring associated with the security system.
The starter interlock is clutch pedal switch B in the diagram below and the button fits into a hole on the clutch lever and pushes on the end of the switch to operate it. It is a major pain to get at and is even difficult to see without the lower valence off. If the starter motor operated before and you have not found any mystery pieces of plastic in the footwell (from the button falling out) since fiddling with the ignition switch then it is probably not the interlock switch button.
The starter interlock is clutch pedal switch B in the diagram below and the button fits into a hole on the clutch lever and pushes on the end of the switch to operate it. It is a major pain to get at and is even difficult to see without the lower valence off. If the starter motor operated before and you have not found any mystery pieces of plastic in the footwell (from the button falling out) since fiddling with the ignition switch then it is probably not the interlock switch button.
yes agree this alarm system is a PITA. I’m close to just having it taken off at this point. I’ve already rechecked all wiring connection, re connected wiring, and tried to even jump start and nothing. It’s definitely something with the ignition switch area cause since I change it out, the battery gauge does not go up
Thanks for the help bro!I'm basking in the glow of my correctness...
Something is definitely screwed up, either with the switch or the vehicle wiring. This shows the connection to the ignition switch
The starter motor circuit is all by itself on the blk/wht wire coming out of the ignition switch. Since the starter motor worked before the switch was replaced I will assume that it is still working. That leaves a limited number of things that can stop the starter motor circuit from operating
- a blown #29 fuse
- a broken wire between the battery to #29 fuse to the ignition switch
- a problem with the ignition switch
- a broken wire from the ignition switch to the starter cut relay
- the OEM security control unit is not providing a ground enable to the starter cut relay.
The voltmeter in the dash gauge is powered up off of the IG1 wire (BLK/YEL) coming out of the ignition switch.
From the wiring diagram you can see that IG1 (BLK/YEL) splits off via fuse #4 to a YEL/BLK wire (2nd diagram) and that wire supplies the instrument cluster (3rd diagram).
In addition to a non operating voltmeter there should be a whole other pile of other stuff that is not operating including the CEL, low oil pressure light ..... There is just a pile of critical stuff on that IG1 circuit including switched power to the OEM security system. The service manual is not explicit about this; but, I suspect that if the security unit does not get a power up signal it will not provide the switched ground to the starter cut relay which will prevent the starter circuit from operating.
There are a limited number of things which can stop the IG1 circuit from operating
- a blown #29 fuse
- a broken wire between the battery to #29 fuse to the ignition switch
- a problem with the ignition switch
- a broken wire from the ignition switch to one or more of the places where IG1 goes which is all over the place.
The first three problems are common to the IG1 and ST circuit so you need to focus there first. Do the following:
1) If you have a voltmeter, check for voltage at the ignition switch plug by back probing the wht/blk/ wire (fuse #12) and the wht/red wire (fuse #29) on the connector. If you have voltage on both those circuits then the first two causes are eliminated.
2) The next step is to remove the switch and confirm that the ignition switch is OK which means checking the continuity of the switch in all 4 positions using the service manual test diagram I included in post #9.
3) Make sure that the switch is re installed in the 0 position.
If the 12v supply to the switch is OK and the switch is OK then that suggests that you have a wiring problem down stream of the switch which could be a major nightmare. I would check the IG1 circuit because it also kills the security module which likely kills the starter cut relay. Visually check the body side harness of the ignition switch plug because the aftermarket security system could be tied in there and you may have disturbed it during the switch changeout.
Make sure you completely carry out steps 1,2 and 3 because you absolutely do not want to be doing the deep dive into the body harness unless you are 100% sure the problem is not in the ignition switch circuit. Aside from the fact that Honda wiring harnesses are incredibly reliable and I really don't think that is where the problem is it will be a nightmare taking the harness apart to trace what may be a non existent fault. It might be better to start from the aftermarket security system connections and trace those to where they interface with the OEM wiring.
The starter motor circuit is all by itself on the blk/wht wire coming out of the ignition switch. Since the starter motor worked before the switch was replaced I will assume that it is still working. That leaves a limited number of things that can stop the starter motor circuit from operating
- a blown #29 fuse
- a broken wire between the battery to #29 fuse to the ignition switch
- a problem with the ignition switch
- a broken wire from the ignition switch to the starter cut relay
- the OEM security control unit is not providing a ground enable to the starter cut relay.
The voltmeter in the dash gauge is powered up off of the IG1 wire (BLK/YEL) coming out of the ignition switch.
From the wiring diagram you can see that IG1 (BLK/YEL) splits off via fuse #4 to a YEL/BLK wire (2nd diagram) and that wire supplies the instrument cluster (3rd diagram).
In addition to a non operating voltmeter there should be a whole other pile of other stuff that is not operating including the CEL, low oil pressure light ..... There is just a pile of critical stuff on that IG1 circuit including switched power to the OEM security system. The service manual is not explicit about this; but, I suspect that if the security unit does not get a power up signal it will not provide the switched ground to the starter cut relay which will prevent the starter circuit from operating.
There are a limited number of things which can stop the IG1 circuit from operating
- a blown #29 fuse
- a broken wire between the battery to #29 fuse to the ignition switch
- a problem with the ignition switch
- a broken wire from the ignition switch to one or more of the places where IG1 goes which is all over the place.
The first three problems are common to the IG1 and ST circuit so you need to focus there first. Do the following:
1) If you have a voltmeter, check for voltage at the ignition switch plug by back probing the wht/blk/ wire (fuse #12) and the wht/red wire (fuse #29) on the connector. If you have voltage on both those circuits then the first two causes are eliminated.
2) The next step is to remove the switch and confirm that the ignition switch is OK which means checking the continuity of the switch in all 4 positions using the service manual test diagram I included in post #9.
3) Make sure that the switch is re installed in the 0 position.
If the 12v supply to the switch is OK and the switch is OK then that suggests that you have a wiring problem down stream of the switch which could be a major nightmare. I would check the IG1 circuit because it also kills the security module which likely kills the starter cut relay. Visually check the body side harness of the ignition switch plug because the aftermarket security system could be tied in there and you may have disturbed it during the switch changeout.
Make sure you completely carry out steps 1,2 and 3 because you absolutely do not want to be doing the deep dive into the body harness unless you are 100% sure the problem is not in the ignition switch circuit. Aside from the fact that Honda wiring harnesses are incredibly reliable and I really don't think that is where the problem is it will be a nightmare taking the harness apart to trace what may be a non existent fault. It might be better to start from the aftermarket security system connections and trace those to where they interface with the OEM wiring.
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Bro! This is good info, at this point I am unable to diagnose as I am bad with electrical. I appreciate you looking into this and the detailed information. My next plan is to rip out this useless old aftermarket security system and take it to my local guy who specializes in auto electrical. This information would definitely point my guy in the right direction. I will keep everyone updated for sure. I think what I messed up was wiring the security system with the new ignition switch. I probably should look at the fuse #29, do you have a pictured diagram where I can find this? The label stickers for all my fuses was taken off or flew off the dessert somewhere 
My familial ties seem to be expanding!
Main relay box in the front compartmentBro! This is good info, at this point I am unable to diagnose as I am bad with electrical. I appreciate you looking into this and the detailed information. My next plan is to rip out this useless old aftermarket security system and take it to my local guy who specializes in auto electrical. This information would definitely point my guy in the right direction. I will keep everyone updated for sure. I think what I messed up was wiring the security system with the new ignition switch. I probably should look at the fuse #29, do you have a pictured diagram where I can find this? The label stickers for all my fuses was taken off or flew off the dessert somewhere
This is for the 1991 model year. Some of the stuff got moved around in later production runs. If you click on NSX Prime Library in the top red banner you can follow links that will take you to .pdf versions of the 1991 service manual and a mostly correct document covering the 1997 - 2005 models. Download one of them because if your 'guy' does not have the service manual with wiring diagrams life is going to be difficult.
At work we would use the honorific "Gee" as short for OG which in turn is short hand for Original Gangster.
Usage: "Hey Gee, I got a question about [subject]."
However, Old Guy is a good backronym for OG on this forum.
One does become like their customers and associates. And OG is the de facto knowledge base provider here, which is much appreciated!
Usage: "Hey Gee, I got a question about [subject]."
However, Old Guy is a good backronym for OG on this forum.
One does become like their customers and associates. And OG is the de facto knowledge base provider here, which is much appreciated!
So, I can extend my title to P. Eng (ret), Bro, OG ?
Thank you for the diagram and will be checking this out today. I have a 94 so it should be the same as the 91. Will keep everyone updated bro
