SaabCentral Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter · #1 ·
Just finished installing a "new" V-6 and I've got a no-crank condition. Before I pull the starter to get it bench checked, I thought I run the symptoms past this forum and see if anyone has any advice for me.

New battery - got 12 volts at the positive cable on the starter solenoid with the key off. When I turn the key to crank, I get 12 volts at the post on the solenoid where the wire from the starter attaches. I also get 9 volts on a smaller gage yellow wire that runs from the solenoid back into the wiring harness. All the lights go out and I hear absolutely nothing from the starter - no clicks, no nothing. I've got the clutch pushed in while I crank in case there's a clutch interlock switch.

Thanks for any help.
 

·
Registered
Joined
·
21,583 Posts
Either the battery is run down or the the test equipment is inaccurate.

A fully charged serviceable battery should be at a minimum of 12.6 v.
Also, the yellow lead to the solenoid should have 12, not 9 v..
The ignition switch must be tested, as well as the cables and the alternator.

Another thing we used to do was place the car in 3rd or 4th and try to push it.
This, the 60s, was an era of seized or locked engines...

Thank goodness that we do not have a clutch interlock - one more un-necessary thing to malfunction.

I'd charge the battery and retest.....
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #3 ·
Battery is 12.6-12.7V key off. Drops to 12.2-12.4V with the key on. I bought it Sunday when the battery in the car at that point wouldn't hold a charge above 8V after being on a trickle charge overnight. Still seeing 9V on that yellow wire - does that go back to ignition? Good idea on rolling it down the driveway and popping it in gear. This car's been off the road so long, it will probably freak out when it starts to go.
 

·
Registered
Joined
·
4,293 Posts
The yellow wire goes to a relay contact at the starter relay in the instrument panel relay tray. You should be able to hear the solenoid click, at least.

When you turn the key to ON, you get power to some accessories, like radio, ACC, etc. That is why the voltage dips slightly.

When you turn the key to start, the starter relay should close, and apply power to the starter solenoid. The solenoid "pulls in", and applies power to the starter. Engine cranks.

You are really dealing with three separate circuits. The starter motor (simple). The solenoid circuit (fairly simple). The ignition switch (not so simple). The diagram is in the Haynes manual.

The solenoid circuit looks like this: Power from the battery positive terminal to the maxi fuse box next to the battery. 60A maxi fuse #2. Orange wire from the fuse to the starter relay. Yellow wire from the starter relay to the solenoid at the starter. The solenoid grounds to the chassis through the starter casing (I think).

I would check to see what happens to the battery voltage at the terminals when you turn the key to start. The 9V may just be because the battery is being loaded by the starter motor while attempting to crank. The solenoid voltage may be 9V, only because the battery which supplies the voltage dips due to momentary load.
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #5 ·
Voltage at the battery drops from 12.6 to 11.6 volts when the key is turned to crank. Not only do I not hear anything from the start, I also noticed I'm not hearing any kind of sound from the fuel pump. Checked at the schrader valve on the fuel rail, an sure enough, no fuel!

Is there some sort of auto shut-down relay that could take both elements out? Or maybe this points to the ignition switch if fuel pump voltage is sourced through the switch somehow. I've checked the fuel pump and starter fuses, as well as all the 60A fuses by the battery. Everything looks good so far.
 

·
Registered
Joined
·
4,293 Posts
On the 4-cyl engines, the ECU only turns on the fuel pump AFTER the engine starts to crank. I would be surprised if it was different on the V6.

It works is like this: The ECU monitors a signal from the Crankshaft Position Sensor (sometimes called CPS, sometimes CKP). The sensor produces a signal like a sine wave when the crankshaft turns. When the ECU sees a valid signal, it turns on the fuel pump via the fuel pump relay.

Since your engine is not turning over, there is no signal from the sensor, and the fuel pump stays off.

The odd thing here, is that if the battery is new, and if power is getting to the starter, which it appears to be, you should hear the starter solenoid click! Even if the starter is bad, or rusted from sitting too long, the solenoid click is hard to miss...
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #7 ·
I've become deaf in a frequency that matches my wife's voice - maybe that's the problem :D. I guess I need to remove that starter and get it tested. That top bolt ain't going to be fun. Just wanted to be sure there wasn't something else unique to a Saab that could be tripping me up.

Interesting that the pump is not energized until you see engine rotation - not at all what I'm used to.
 

·
Registered
Joined
·
4,293 Posts
Drabix said:
...I guess I need to remove that starter and get it tested...
I keep thinking you should hear the solenoid clicking when you turn the key to "Start", even if the starter is bad... maybe someone else has a clue, I am out of ideas.
 

·
Registered
Joined
·
21,583 Posts
To isolate all components in the starter circuit, run jumper cables from a known good battery to the unit..Or you can just run some current thru the yellow lead(bypassing the ignition switch and the relay). this is easy...

If she operates then, back track, check the cable.
Check the yellow lead from the relay to the starter solenoid, should have 12 volts.

I have seen 9 volts posted for the starter solenoid(yellow wire) - it should be 12...

Also, I have noticed a 1 volt drop when the starter position is in use - this is correct, if the starter is working. If it is not, then , I do not know..
 

·
Registered
Joined
·
1,388 Posts
PMI said:
On the 4-cyl engines, the ECU only turns on the fuel pump AFTER the engine starts to crank. I would be surprised if it was different on the V6.
Surprise! The V6 is different in that when you turn the key from off to on, the fuel pump WILL prime the system, on mine you can hear the fuel pump prime for a brief moment before you turn the key to crank the starter.

Umm I know you've been checking for +12V but have you been checking your grounds as well? As I recall there is only a single Ground wire coming off the battery to the front of the transmission. Either add another ground wire or use jumper cables and jump the negative battery post to the starter directly.

Also did you make sure that the little braded wire that connects the solenoid to the starter motor is not damaged?
 

·
Registered
Joined
·
4,293 Posts
Diosnoche said:
Also did you make sure that the little braded wire that connects the solenoid to the starter motor is not damaged?
I was trying to remember if there was something like that! Good catch.
 
1 - 11 of 11 Posts
Top