Now it won't start!

E

El-Cojonico

Contributing Member
Joined
10 March 2019
Messages
105
Location
Miami, FL
My 94 Automatic won't start. I replaced the ignition switch, main relay and battery. Everything sounds like it should start. I can hear the fuel pump prime but the starter never engages. Is there any security "Kill switches" built in...the car is all stock. I'm so frustrated. Any fuses I should look into. I know with 133k miles my starter might be going, but it sounded great last time it started. Please help!!!! Aside from replacing the throttle body and removing the subwoofer, nothing has been changed.
 
Small update. In a prior post, it was mentioned to add power to the where the small black/white cable makes connection to the male connection coming out of the side of the starter to see if the solenoid engages. I added power and got nothing. My money is now on the starter. Can anyone confirm....or add other suggestions. Thanks.
 
So, to be clear, right now the problem appears to be just that the starter motor is not cranking when you switch the key to the start position? If so, then to your question about kill switch, there is a relay called the starter cut relay which prevents the starter motor from engaging. The cut relay is controlled by an interlock switch on the shift lever (prevents starting unless in Park or neutral) and the security system. Attached is the wiring diagram for the starter motor circuit.

You should first check the status of fuse #29 . If it is blown it will prevent the starter motor from operating. However, if it is blown it would also affect a bunch of other stuff so I would have expected that you would have noticed that. But, best to rule it out as a possibility. You might have blown the fuse during your ignition switch replacement if you didn't disconnect the battery.

Since you have presumably eliminated the ignition switch as the problem and if fuse #29 is OK, one way to find out where the problem exists is to remove the starter cut relay and using some 1/4" crimp style spade connectors, fashion a jumper to connect between the black/ white and the black blue wires in the socket (the relay is in the dash requiring removal of the glove box to get access - not exactly convenient) . This completely by passes the starter cut relay / shift position console switch / security control unit functions. If the starter motor now works, you know that the problem is with the starter cut relay or the shift position console switch or security control unit. If the starter motor does not start then the starter motor may be dead or you have a broken wire someplace. If the starter motor is dead, it is frequently just the contacts on the solenoid that have failed which can be repaired for a few dollars. There is a thread on Prime describing the repair of the solenoid contacts.

You will need to download a copy of the electrical section of the 1991 service manual t find the exact location of the starter cut relay (Honda moved stuff around during the production run). The service manual also provides a step by step procedure for diagnosing the source of the problem in the starter cut relay / shift position console switch / security control unit circuit.

If the problem is in the starter cut relay / shift position console switch / security control unit circuit, you can leave that jumper in place and drive the car until you fix the problem. However, the immobilizer function associated with the security system will not be operational (car is easier to steal) and you will be able to start the car with the transmission in gear which would be a safety issue potentially result in drivetrain damage. Informed is forewarned!
 
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El-Cojonico said:
Small update. In a prior post, it was mentioned to add power to the where the small black/white cable makes connection to the male connection coming out of the side of the starter to see if the solenoid engages. I added power and got nothing. My money is now on the starter. Can anyone confirm....or add other suggestions. Thanks.
Click to expand...

Yes, if you applied +12v to the solenoid terminal on the starter motor and nothing happened, then ignore my previous post and fast forward to starter motor removal! Replacement Denso starters from Rockauto are not super expensive; but, chances are that the motor itself might be OK and that it is just the solenoid contacts that have failed. There is a thread on Prime describing the repair if you search. That said, if you got absolutely no sound at all from the solenoid, the solenoid coil may have failed and repairing contacts is not going to help that. Either way, the starter motor has to come out for inspection. The service manual will take you through testing and diagnosis of the starter motor.
 
If you haven't started the removal process yet, you can try a gentle tap on the side of the starter / solenoid with a ball peen hammer - nothing hard enough to dent the case! I recognize that doing the tap thing is difficult on an NSX. Sometimes this will persuade a starter to resume operation; but, it is usually a temporary resumption. After 25 years of service, you shouldn't feel bad about having to do removal to repair the starter. New starters are about $850 at the discounters so you are probably going to want to check out the reman or repair options. Rock Auto has Denso remans for less than $100 after the core refund.
 
Seems like the 'hot ticket'.

Since you don't need to return the core, don't throw it out. As far as I can tell the starter is unique to the NSX. In 10 - 15 years even remans might be unavailable and your starter might be a life-line for somebody after it is rebuilt.
 
I hear you on the starter issues. The good thing about the starter is that it may be easy to diagnose. If you just get a hammer or wrench and bang on it while someone cranks the car, you can diagnose if it's going bad. I already had two go bad on me... I wonder if anyone around me can rebuild it. When I got my starters they were about $150 each (not OEM of course).​
 
Too late, however I will buy the kit and fix the old one incase they become rare or I need another one. For now, you cant beat Amazon (Denso) rebuilds.
 
How are the Amazon rebuilds rebuilt? :wink: see video plus a bit of cleaning
Click to expand...

For $102, unless this was an overstock or clear-out item you have to know that the amount of rebuilding was minimal. For a manufacturer with a financially sustainable reman business, they would typically pay a core charge of around $40 which leaves $62 for repair parts, throw away on starters that can't be rebuilt, labour and overhead costs plus profit. That is not going to allow much to be allocated for labour and parts. The armature and solenoid coil get tested for continuity and shorts. I expect that shorts or open circuits send the starter to the garbage can because there is no way you are fixing those for $60. At the $102 price, I expect that at best the contacts on the solenoid get replaced and perhaps the brushes if they are bad. A really bad bearing or bushing might get replaced just so the vendor can recover some costs by selling the starter. The commutator probably gets a polish with some SiC paper, lube the parts and that is it.

The Denso name brand remans sold be RockAuto are about $125 (including core charge). The core refund is about $33 which leaves about $90 for everything else (including Rockauto's mark up). More $ than the Amazon special; but, not a lot. Since the Denso claims to also have new bearings, I have to think that they must be using some real sweat shop labour to be able to pedal these things at the price they do.

I have an acquaintance who has a large collection of ancient to new vehicles. Basically a sucker for anything with four (or more) wheels and can move under its own power. A complete rebuild on a starter from one of his obscure vehicles by a restoration specialist typically has 4 numbers in the price tag before you hit the cents.
 
Old Guy said:
Seems like the 'hot ticket'.

Since you don't need to return the core, don't throw it out. As far as I can tell the starter is unique to the NSX. In 10 - 15 years even remans might be unavailable and your starter might be a life-line for somebody after it is rebuilt.
Click to expand...

Old Guy, quick question as you are the best to run this by :) Do you know if there is any certain voltage cut off? Not to hijack the thread but I been having sort of a newsense issue where when the car is at 12.4v it will not start but the minute it turns 12.6v it starts strong. When started it is 14v, so it's def charging from alternator. But what I notice the car would not even attempt to turn the starter if it's at 12.4v, like a certain relay or board would detect low voltage and not pass the signal. I use booster battery to jump it and its all good again. But this comes and goes.

Thanks,
David
 
Before spending $100 or $125 for a part of an unknown quality - even if it says Denso on it (there ARE fake parts out there) - I'd rather rebuild the existing one. The kit is $10 ($30 for me with shipping...). The coils and bearings don't go bad that often in a Denso of the 90ies (not sure about today's quality). But I'd surely NOT install any cheap Chinese crap in my NSX for 10x more than needed.

Yes, I doubt the rebuilt quality of the $100 versions. There are also rebuilt A/C compressors out there and sometimes you have to buy 3 of them because 2 failed after a short time. I'm just a parrot here, the arguement against rebuilt A/C compressors is from ETC and Scotty Kilmer. :)
 
nsxmugen said:
Old Guy, quick question as you are the best to run this by :) Do you know if there is any certain voltage cut off? Not to hijack the thread but I been having sort of a newsense issue where when the car is at 12.4v it will not start but the minute it turns 12.6v it starts strong. When started it is 14v, so it's def charging from alternator. But what I notice the car would not even attempt to turn the starter if it's at 12.4v, like a certain relay or board would detect low voltage and not pass the signal. I use booster battery to jump it and its all good again. But this comes and goes.

Thanks,
David
Click to expand...

From this statement

But what I notice the car would not even attempt to turn the starter if it's at 12.4v,
Click to expand...

I gather that the no start is the starter motor won't engage?

First, the easy part. There is no designed in low voltage cut off / interlock in the starter motor circuit. .

With absolutely no load on a 12 v lead acid battery (needs to be disconnected from the car because of the parasitic loads), a battery terminal voltage of 12.9 volts indicates 100% charged and a battery voltage of 11.4 volts indicates totally discharged and perhaps a candidate for the recycler. Close to the top, this web page has a nice graphic showing charge versus voltage.

https://batteryuniversity.com/learn/...tate_of_charge

Your 12.4 - 12.6 volts says that your battery is running at about 55% charge at best so not in great shape (I am assuming you have a lead acid battery). If your alternator is running at a nice 14 volts or a nudge higher I would expect that a good battery should be showing closer to 12.9 volts unloaded - assuming you are using a reasonable quality multimeter to measure voltage, not the dash gauge.

In order to get the starter motor to start, the battery has to have a voltage high enough to get the starter solenoid to engage which closes the main contacts on the starter motor causing it to operate. I would expect that 12.4 volts should easily be good enough to cause the solenoid to engage and that you should be getting starter action. Why there is a cut-off between 12.6 v and 12.4 v is a mystery.

That said, I suggest two tests. The first and easiest one is connect a voltmeter to the convenient jump start terminal in the engine fuse & relay box. Have someone try to crank the starter. If the starter does not start and the voltage at the jump start terminal goes in the toilet, then you likely have a bad connection at the battery post or the battery has an internal problem. I had a random starting problem after I got my NSXr and I discovered that the battery cable clamps had been stretched by somebody over tightening them and I could lift the clamp right off the post without loosening anything. If the voltage at the jump start terminal stays above 12v but the starter does not engage the battery and connections are probably OK and its time for part 2. Insert a little jumper in the connection to the starter solenoid that will allow you to measure the voltage at the solenoid terminal (this can be a bit of a hassle). Measure this voltage while you have somebody try to crank the starter. If the voltage stays above 12v and the starter does not engage then you have some kind of internal problem with the starter. If the voltage takes a nose dive when you attempt to start the car then you have an upstream problem in the solenoid circuit and the likely candidate would be the ignition switch which can be intermittent before they fail completely
 
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Old Guy said:
From this statement



I gather that the no start is the starter motor won't engage?

First, the easy part. There is no designed in low voltage cut off / interlock in the starter motor circuit. .

With absolutely no load on a 12 v lead acid battery (needs to be disconnected from the car because of the parasitic loads), a battery terminal voltage of 12.9 volts indicates 100% charged and a battery voltage of 11.4 volts indicates totally discharged and perhaps a candidate for the recycler. Close to the top, this web page has a nice graphic showing charge versus voltage.

https://batteryuniversity.com/learn/...tate_of_charge

Your 12.4 - 12.6 volts says that your battery is running at about 55% charge at best so not in great shape (I am assuming you have a lead acid battery). If your alternator is running at a nice 14 volts or a nudge higher I would expect that a good battery should be showing closer to 12.9 volts unloaded - assuming you are using a reasonable quality multimeter to measure voltage, not the dash gauge.

In order to get the starter motor to start, the battery has to have a voltage high enough to get the starter solenoid to engage which closes the main contacts on the starter motor causing it to operate. I would expect that 12.4 volts should easily be good enough to cause the solenoid to engage and that you should be getting starter action. Why there is a cut-off between 12.6 v and 12.4 v is a mystery.

That said, I suggest two tests. The first and easiest one is connect a voltmeter to the convenient jump start terminal in the engine fuse & relay box. Have someone try to crank the starter. If the starter does not start and the voltage at the jump start terminal goes in the toilet, then you likely have a bad connection at the battery post or the battery has an internal problem. I had a random starting problem after I got my NSXr and I discovered that the battery cable clamps had been stretched by somebody over tightening them and I could lift the clamp right off the post without loosening anything. If the voltage at the jump start terminal stays above 12v but the starter does not engage the battery and connections are probably OK and its time for part 2. Insert a little jumper in the connection to the starter solenoid that will allow you to measure the voltage at the solenoid terminal (this can be a bit of a hassle). Measure this voltage while you have somebody try to crank the starter. If the voltage stays above 12v and the starter does not engage then you have some kind of internal problem with the starter. If the voltage takes a nose dive when you attempt to start the car then you have an upstream problem in the solenoid circuit and the likely candidate would be the ignition switch which can be intermittent before they fail completely
Click to expand...

Awesome, thanks !! will give that a try next time it happens. Of course now that I have something to try/test it won't happen :)
 
nsxmugen said:
Awesome, thanks !! will give that a try next time it happens. Of course now that I have something to try/test it won't happen :)
Click to expand...

That is the precise definition of intermittent failure!
 
Old Guy said:
That is the precise definition of intermittent failure!
Click to expand...

Ok, it just happen today. I think you nail it, it got to be the cable between battery and engine relay box in my case at list. The cable does look very tired and I see some individual strings got green coating on.

For others benefit I log the volt meter readout and here how it looks, volt just dip but engine does not crank. It was 12.5v but once I turn ignition it went to 12.19v then down to 11.87v when I turn the key.

Do you know what gauge cable can it be replaced with or a good place to get it from?

b461185a3813737d0e1d156cff86b060.jpg


Thanks!!


Sent from my iPhone using Tapatalk Pro
 
I would assume, unless somebody finds the part number, that its probably like a common battery cable but with to smaller eye openings. Let me know what length it is. Mine was kinda green too. It seems like an easy maintenance replacement.
 
Are you talking the main cable from the battery to the main fuse box in the engine compartment? That is no 'common' battery cable. First off, it is really big. I think its 1/0 which helps to make it expensive. It is also a major effort to replace. In 9 years of cruising Prime, I don't recall a thread discussing 'actual replacement' of that cable. There are a bunch of threads covering replacement of the OEM battery lug on the cable which is the common failure point.

http://www.nsxprime.com/forum/showt...eplacement?highlight=battery+cable+clamp+size

Even replacing that lug is a non trivial exercise just because it is such a pain getting down there to work on things and you definitely are not using a hand crimper to attach a 1/0 lug. I had to replace the battery clamps on my car and I had to go to an electrical specialist who did 'big truck' work to find clamps with the correct wire sizes.

User Redbird (Daisy Automotive) was fabricating & selling a nice replacement for the negative battery cable which grounds to the body. Aside from suffering the same lug failure problem as the + cable it can also suffer from corrosion at the body connection. If you want to pre-emptively replace something, replace the negative cable with Redbird's cable and plan for replacement of the battery lug on the + cable.

If you feel compelled to replace the + cable, welding cable provides a nice solution. Very fine strand (990 strands on 1/0) which makes it very flexible and lots of insulation (typically rated 600 V). Because of the EPDM jacket, it is probably bulkier than the OEM cable. Price is nicer. You should be able to source it for about $5 /ft. The fine stranding can make crimping a bit more hassle; but, doable. Same major headache doing replacement!
 
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As designed by Honda, the cable from the main fuse box to the starter motor is part of the long cable from the main fuse box to the battery. Its part # is 32410 SL0 A02. As I recall, the long 'battery' cable and the shorter 'starter' cable are both crimped to a plate and the plate is bolted to the jump start terminal in the main fuse box. You should do a visual check; but, that is my recollection when I investigated my battery clamp replacement exercise long ago.

You might be able to hacksaw that joining plate in half and just fabricate a new cable to the starter with appropriate lugs for connection at the fuse box and the starter motor. Take the old cable to a good auto electric specialist and they should be able to fabricate it for you. After hacksawing the joiner plate in half, you would need to make sure that the connection at the jump start terminal makes a satisfactory connection between the battery cable and the starter cable - you need to figure that bit out!

With respect to the green stuff on the cable, its likely a copper oxide (actually a carbonate I think). Unlike rust on iron / steel, copper oxides usually just stay on the surface and the base copper stays OK so the cable may be just fine. You could clean the terminal by dipping in vinegar which should remove the tarnish and allow you to check the copper for damage. For the copper to form an oxide like that, it has to be exposed to sustained moisture or really high humidity (I suppose Miami could do that). If you are obsessive about washing the engine compartment - don't. If you clean up the terminals, apply a section of double wall heat shrink on the gap between the cable jacket and the crimped lug to protect the copper from further oxidation. Covering the lugs with a light coat of grease will prevent oxidation of the those terminals. You can use a compound like No Ox on the exposed lugs /terminals to prevent corrosion of those terminals.
 

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