Low starter solenoid voltage
Thread Starter
Intermediate
Joined: Dec 2003
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From: Kingston ontario
Low starter solenoid voltage
Hey all,
I'm having a weird starting problem with my 90.
When the car is hot, and you turn it over, you can hear the starter gear disengage very quickly sometimes, then re-engage.
I got under the car and measured the voltage to the "big" cable going to the starter. It measured 12 volts. I jumpered it over to the smaller connector on the starter, and it turns over perfectly.
I then disconnected the small cable and hooked it up only to my voltmeter. When the key is turned to the start position, there's only 8 volts coming from that small cable. That's the cable that engages the starter gear, if i understand correctly.
I guess that explains why the gear isn't staying engaged all the way.
My question is, where the heck does that little cable come from? Does it go straight back to the ignitions switch in the steering column?
Should i try to measure the voltage right at the ignition switch? Or should i try to trace that cable back to somewhere near the firewall and test the voltage there?
Thanks for any suggestions you might have!
Scott
I'm having a weird starting problem with my 90.
When the car is hot, and you turn it over, you can hear the starter gear disengage very quickly sometimes, then re-engage.
I got under the car and measured the voltage to the "big" cable going to the starter. It measured 12 volts. I jumpered it over to the smaller connector on the starter, and it turns over perfectly.
I then disconnected the small cable and hooked it up only to my voltmeter. When the key is turned to the start position, there's only 8 volts coming from that small cable. That's the cable that engages the starter gear, if i understand correctly.
I guess that explains why the gear isn't staying engaged all the way.
My question is, where the heck does that little cable come from? Does it go straight back to the ignitions switch in the steering column?
Should i try to measure the voltage right at the ignition switch? Or should i try to trace that cable back to somewhere near the firewall and test the voltage there?
Thanks for any suggestions you might have!
Scott
Melting Slicks
Joined: Dec 2004
Posts: 2,137
Likes: 5
From: Howard PA
Does a '90 have VATS? If not the voltage comes probably comes from directly from the ignition switch under the steering column.
If the car has VATS the ignition switch provides 12 volts to the solenoid through an interposing VATS relay that acts as nothing more than an on/off switch.
Somebody with a '90 starting schematic could easily confirm this.
If the car has VATS the ignition switch provides 12 volts to the solenoid through an interposing VATS relay that acts as nothing more than an on/off switch.
Somebody with a '90 starting schematic could easily confirm this.
Thread Starter
Intermediate
Joined: Dec 2003
Posts: 28
Likes: 0
From: Kingston ontario
Thanks for your reply.
Yes it does have VATS.
If it was a VATS problem, i don't think it would turn over at all, would it?
Mine does turn over, but because of the low voltage to the small wire, you can hear the gear disengage and re-engage.
Another weird thing. I just checked (what i think is) the ignition switch.
It's down sort of mounted on the side/top of the steering column.
The weird thing is that the rod wasn't even seated inside the little hole in the ignition switch. I managed to get it in there, and i watched it as i started the car. That rod didn't even more at all! What the heck?
Do i have to loosen that nut and slide the whole switch?
And the craziest part is that i unhooked the connector to that thing and the car still turned over! lol. maybe i'm looking at the wrong thing.
Yes, i 90 schematic would be greatly appreciated.
Yes it does have VATS.
If it was a VATS problem, i don't think it would turn over at all, would it?
Mine does turn over, but because of the low voltage to the small wire, you can hear the gear disengage and re-engage.
Another weird thing. I just checked (what i think is) the ignition switch.
It's down sort of mounted on the side/top of the steering column.
The weird thing is that the rod wasn't even seated inside the little hole in the ignition switch. I managed to get it in there, and i watched it as i started the car. That rod didn't even more at all! What the heck?
Do i have to loosen that nut and slide the whole switch?
And the craziest part is that i unhooked the connector to that thing and the car still turned over! lol. maybe i'm looking at the wrong thing.
Yes, i 90 schematic would be greatly appreciated.
Thread Starter
Intermediate
Joined: Dec 2003
Posts: 28
Likes: 0
From: Kingston ontario
I'm starting to think it's my neutral safety switch.
I've just had a look at it, and it kinda looks burnt-ish and smokey a bit.
Does anyone know how i can bypass it just to test it out?
There are like 6 wires on that connector. I figure i'd have to put a paper clip from one pin to another one to close the switch.
It might be more complicated than that, considering there are 6 wires, however.
Scott
I've just had a look at it, and it kinda looks burnt-ish and smokey a bit.
Does anyone know how i can bypass it just to test it out?
There are like 6 wires on that connector. I figure i'd have to put a paper clip from one pin to another one to close the switch.
It might be more complicated than that, considering there are 6 wires, however.
Scott
Large Impressive Member
Joined: Jul 2003
Posts: 65,811
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
I've seen this problem many times on older cars just from degraded wires that caused the excessive voltage drop. But I suppose it's quite possible that a failing neutral switch could also cause the excessive resistance, especially from your description of it.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
You can safely jump the clutch safety switch, but it should be with a wire larger than a paper clip because the starter solenoid initially draws large current. I recommend a short piece of #14 wire. The small wire on the starter which is the start solenoid wire goes to a pin on the firewall connector on the firewall. The firewall connector on the inside of the car has a wire that goes to the clutch safety switch socket. The other wire on the clutch sw goes to the start enable relay. The second wire on the start enable relay goes to the ignition switch. A burned clutch sw can cause a resistance in the starter solenoid circuit which will limit current and low voltage at the starter solenoid which you have already found.
Melting Slicks
Joined: Dec 2004
Posts: 2,137
Likes: 5
From: Howard PA
Well the way it works on my 96 with VATS; the netral safety switch or clutch switch just interrupts the coil for the VATS relay. Thereby disabling the starter.
You need a schematic like this for your 90 but this 96 might be the same setup, you'd have to verify...
It's very possible the VATS relay has some dirty contacts or the firewall bulkhead connector is getting "iffy"
You need a schematic like this for your 90 but this 96 might be the same setup, you'd have to verify...
It's very possible the VATS relay has some dirty contacts or the firewall bulkhead connector is getting "iffy"
Last edited by ALLT4; Aug 14, 2006 at 10:15 PM.
Large Impressive Member
Joined: Jul 2003
Posts: 65,811
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
I have a button mounted under my hood to activate the starter. Comes in handy when adjusting the valves. You could do the same thing inside the car for a reliable ghetto-fix. 
Simple two wire circuit.
Simple two wire circuit.
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Thread Starter
Intermediate
Joined: Dec 2003
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From: Kingston ontario
That was it! It was the Neutral Safety Switch!
When i looked at the connector for the NSS, it was obvious which 2 i had to jump. The 2 big ones on the connector.
So yes, for now i just have a paper clip in there.
Do you think i can get away with it until i buy a new NSS? Or at least put a heavier gauge jumper on there?
You have no idea how relieved i am. It was embarassing when people were around and i had to start my car and it made that ****ty noise. lol.
I could tell that they loved it, in a way, to see mr. hot **** in a vette, having problems. hehe
Thanks everyone, for the help!
When i looked at the connector for the NSS, it was obvious which 2 i had to jump. The 2 big ones on the connector.
So yes, for now i just have a paper clip in there.
Do you think i can get away with it until i buy a new NSS? Or at least put a heavier gauge jumper on there?
You have no idea how relieved i am. It was embarassing when people were around and i had to start my car and it made that ****ty noise. lol.
I could tell that they loved it, in a way, to see mr. hot **** in a vette, having problems. hehe
Thanks everyone, for the help!
Large Impressive Member
Joined: Jul 2003
Posts: 65,811
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Yes, if you're going to use it that way for a while, most definitely put an appropriately sized jumper wire in place.
Thread Starter
Intermediate
Joined: Dec 2003
Posts: 28
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From: Kingston ontario
I'll put a better jumper in it tomorrow.
I might as well price out a new switch as well. I'm guessing it's not the cheapest part in the world.
I also had to put a jumper in for the rear hatch button to work. Now i can pop the hatch while i'm driving down the road at 150MPH if i want to. LOL
I might as well price out a new switch as well. I'm guessing it's not the cheapest part in the world.
I also had to put a jumper in for the rear hatch button to work. Now i can pop the hatch while i'm driving down the road at 150MPH if i want to. LOL
Thread Starter
Intermediate
Joined: Dec 2003
Posts: 28
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From: Kingston ontario
Yeah, thanks for putting up that schematic.
I looked at it and it didn't seem like it would be the same as mine.
In yours, it looks like the neutral safety switch can just open that switch that's in theft deterent relay, but doesn't actually carry much current itself. I dunno, though, maybe i'm just reading it wrong.
But yeah, thank god it's working now!
I looked at it and it didn't seem like it would be the same as mine.
In yours, it looks like the neutral safety switch can just open that switch that's in theft deterent relay, but doesn't actually carry much current itself. I dunno, though, maybe i'm just reading it wrong.
But yeah, thank god it's working now!
