Lets talk about this annoying hot start problem...

[msvx95]

Well just an update from me and Happy New Years....I just installed my rebuilt starter and the car starts right up everytime, no probs and now I'm happy.

[Dessertrunner]

Grest news Matt.
Tony

[Trevor]

Originally Posted by oab_au

I have written this before, but it is still the same. The US car seems to have a few series switches in the solenoid circuit, that the Australian model does not have. These switches have sliding contacts that have to carry a high current to pull the solenoid armiture and starter gear in, to operate the starter motor itself. Toms hammer methoid, shakes the solenoid armiture loose, so that it will slide up to the motor contacts.

The starter solenoid circuit, has two sets of windings in it. The first action is to apply power to a low current, hold-in circuit, and a high current pull-in circuit. The pull-in circuit also flows down through the starter motor itself, to start the motor gear rotating, so that it will mesh with the ring gear teeth. When the solenoid armiture does pull the gear into mesh and reaches the end of the solenoid it switches the main current to the starter motor on, it also switches the pull-in circuit off, so that only the hold-in circuit is left in operation.

Harvey.

It would appear very strange that Subaru would fit a different starter motor to the US model. If the complicated arrangement described is in fact used, there will be evidence within the US manuals.

It would be much appreciated if someone, other than the author, can advise if this arrangement does in fact exist.

[Beav]

That's a pretty common arrangement/method for automotive starters since the 1950s. Others would include physically mashing a pedal on the floor to push the starter drive forward and closing the main contacts or the Ford method of using the backside of the field coils to magnetically pull a lever yoked to the drive. The Ford starters used a fender-mounted starter relay vs. the dual-duty solenoid typically found on all other makes.

I'll guess that most here are going to find that this issue stems from either the ignition or inhibitor switches. Certainly, weak solenoids are a common issue for Japanese starters but I've found that rare for SVX/Subarus. I suppose it's due to the mounting position, away from the heat of exhaust.

[Trevor]

Originally Posted by Beav

That's a pretty common arrangement/method for automotive starters since the 1950s. Others would include physically mashing a pedal on the floor to push the starter drive forward and closing the main contacts or the Ford method of using the backside of the field coils to magnetically pull a lever yoked to the drive. The Ford starters used a fender-mounted starter relay vs. the dual-duty solenoid typically found on all other makes.

I'll guess that most here are going to find that this issue stems from either the ignition or inhibitor switches. Certainly, weak solenoids are a common issue for Japanese starters but I've found that rare for SVX/Subarus. I suppose it's due to the mounting position, away from the heat of exhaust.

Thanks for the input Beav.

I am aquatinted with the types of starters you describe. I well remember a 1937/8 Oldsmobile I once had the use of, which had a foot pedal engaged and energised starter. Also English systems with a simple inertia only engagement of the pinion. What about Henry and his very sensible integral system on the model T.

I am also conversant with modern soft start systems, whereby there is a split winding on the solenoid arranged to provide a sequence of operation. The starter motor is in series with a winding which forms a series resistance when the start signal is first delivered, so as to turn the motor a little. A primary winding with a direct ground connection, is energised at the same time, resulting in the solenoid armature moving inwards to first engage the pinion and subsequently close the main contacts, so as to supply full voltage to the motor. The delay times are dependant on component bulk and inertia.

The point is that this modern soft start arrangement does not require extra sliding contacts as has been stated by Harvey. The JDM and Australian models have the usual soft start arrangement. Why would the US model have something weird, inferior and different?

[b3lha]

Originally Posted by oab_au

The US car seems to have a few series switches in the solenoid circuit, that the Australian model does not have. These switches have sliding contacts that have to carry a high current to pull the solenoid armiture and starter gear in, to operate the starter motor itself.

Originally Posted by Trevor

It would appear very strange that Subaru would fit a different starter motor to the US model. If the complicated arrangement described is in fact used, there will be evidence within the US manuals.

It would be much appreciated if someone, other than the author, can advise if this arrangement does in fact exist.

It is certainly a possibility. It may be part of the USDM security system.

My haynes manual for the 5MT USA Legacy shows "clutch" and "neutral" switches to prevent the car from being started when it is in gear . These switches are not fitted to the UK model.

[Trevor]

Originally Posted by b3lha

It is certainly a possibility. It may be part of the USDM security system.

My haynes manual for the 5MT USA Legacy shows "clutch" and "neutral" switches to prevent the car from being started when it is in gear . These switches are not fitted to the UK model.

I include extracts from the original text which are involved:-

Note -- "Toms hammer methoid, shakes the solenoid armiture loose, so that it will slide up to the motor contacts." This indicates the contacts mentioned are integral with the starter.

N.B. -- "it also switches the pull-in circuit off". This action would require the opening of contacts."

On further consideration, it would appear that a description of how a soft start system operates, with emphasis on the US model, has been studied, but has not been properly understood. The pull in circuit is not in fact turned off and importantly remains in circuit, otherwise the solenoid would not open, when the start signal circuit is de-energised.

As a result, it would appear that a wrong conclusion has been reached that the US system is different from the Australian and JDM arrangements, as illustrated within the manuals on hand. These do not show the details of the solenoid assembly, which in fact includes a double wound coil and the circuitry involved.

[oab_au]

First, the starter motors are the same on both US and others. As Phil says the US model
has a few more series switches, that our model does not. The whole trouble stems from
the level of current that the starter solenoid draws. It is this current that burns the contacts
on the ignition switch, and the inhibitor switch.

I’ll explain what goes on in this circuit of the starter solenoid. Here we have the circuit,
that shows two windings on the solenoid. The ‘Pull in’ and the ‘Hold in windings.

When you turn the key, the current flows through the hold in windings to earth. It also
flows through the pull in windings, to the starter terminal, to start the motor turning the
gear, as it is pulled into mesh with the ring gear.

A resistance measurement from the spade terminal for both these parallel circuits reads
about 0.4 ohms. At 12 V this is 30 amps, at 10 V is 25 amps.

When the armature reaches its full travel, pulling the gear into mesh, it turns on the main
contacts to the starter motor. This turns the pull in coil off by connecting 12 V to both
ends of the winding, leaving just the hold in coil engaged, while the starter turns the
engine over.

When the engine starts, and you let the key back, the 12V positive is removed from the
spade terminal, to leave the two windings connected in series to the 12V from the main
starter terminal. This causes the current to flow backwards through the pull in windings,
and forwards through the hold in windings. The two magnetic fields are cancelled, and
the spring pulls the armature away from the main contacts to turn the starter motor off.

So if you have this problem, certainly do the trouble shooting, to find and replace the burnt part.
Then fit a 30 amp Bosch relay to the solenoid to remove this high current flow from these
components, so they won’t fail again.

Harvey.

[Trevor]

It is now confirmed that the original wording, “ switches the pull-in circuit off, ” was incorrect as I pointed out. As I was aware, the circuit is bypassed, not switched or opened. The original description should have been worded, “ bypasses the pull-in circuit." The coil in fact remains in circuit as an essential factor. If the circuit was switched off, the solenoid would remain locked in after release of the ignition switch.

It is now noted that the wording has been amended to read, “ turns the pull in coil off,“ which is still not correct and should read, bypasses the pull in coil. Qualified engineers are careful to use correct and exact language for obvious reasons.

[SomethingElse]

bump for another no start thread

[Manarius]

Yeah, I've got this clicking business going on too, with the Bosch 30amp relay attached. I just think my starter is shot. Anybody have some tips on removal and replacement?

[Trevor]

Originally Posted by Manarius

Yeah, I've got this clicking business going on too, with the Bosch 30amp relay attached. I just think my starter is shot. Anybody have some tips on removal and replacement?

Is the Bosch relay in fact closing? If not, the original fault, which will no doubt still exist, may have increased in resistance, such that the relay does not now operate properly. Worth checking before stripping things apart.

[Manarius]

Originally Posted by Trevor

Is the Bosch relay in fact closing? If not, the original fault, which will no doubt still exist, may have increased in resistance, such that the relay does not now operate properly. Worth checking before stripping things apart.

I don't know what you mean by closing (math major not engineering). When I first put in the relay, it immediately cured all my starting issues, but they've started to creep back in for some reason.

This is a hot and cold problem (although, it's probably worse when it's hot).

[Trevor]

Originally Posted by Manarius

I don't know what you mean by closing (math major not engineering). When I first put in the relay, it immediately cured all my starting issues, but they've started to creep back in for some reason.

This is a hot and cold problem (although, it's probably worse when it's hot).

Closing indicates that the armature, the moving part of the relay, has been magnetically moved towards the fixed pole piece, thus closing the gap between. Importantly, this action also closes the electrical contacts. Moving contacts are fitted to the armature to close against fixed contacts. In effect a switch has been electrically closed. There can be several sets of contacts, both normally open and or normally closed, as well as all sorts of variations, both mechanical and electrical.

Heat often stirs up all sorts of problems. through contraction or expansion taking place.

[SomethingElse]

Originally Posted by Trevor

Closing indicates that the armature, the moving part of the relay, has been magnetically moved towards the fixed pole piece, thus closing the gap between. Importantly, this action also closes the electrical contacts. Moving contacts are fitted to the armature to close against fixed contacts. In effect a switch has been electrically closed. There can be several sets of contacts, both normally open and or normally closed, as well as all sorts of variations, both mechanical and electrical.

Heat often stirs up all sorts of problems. through contraction or expansion taking place.

you were on the right track the whole time.