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Slow Cranking with Skytech LS

petehowell

Well Known Member
This has all been covered before, but wanted to add my experience. 1865 hour RV-9A with O-320 started cranking slowly on our trip to chase the Great Eclipse. PC680 was 6 years old, so we replaced that, no real change.

Original firewall master and starter solenoids - OK they owe me nothing at this point - 'bout time to replace those and clean up all the wiring contacts.......no real change in starting, cranks slow, but always starts. Wife comments that I had better fix that.....

Trip up to Lake Superior for lunch, starter spins, but does not engage engine, but fires up on second try. Dim bulb goes off in dim guy's head that there is another solenoid on the starter that not only engages the flywheel, but also connects the motor to the BA current. It was all here for me to read, but now I got it.

The solenoid on the Skytec starter is off a 2005 Ford Crown Vic(thanks to VAF for that gem!) Picked one up ($20 on sale no less!) and did a 20 min install. She now engages and spins like a champ again.

My 1987 Suzuki Samurai Alternator and 2005 Crown Vic Solenoid are now best buddies on the front of my engine and have lifetime warranties!

tldr - Don't be like Pete, be smart. There are 3 solenoids, know about them all.....
 
Solenoid part number?

Pete do you know if the solenoid is common to any other cars? I may need to do the same thing but we don't have the Ford Crown in Australia. Hoping the solenoid is generic.
 
Pete do you know if the solenoid is common to any other cars? I may need to do the same thing but we don't have the Ford Crown in Australia. Hoping the solenoid is generic.

I am not Pete but I have stayed in a Holiday Inn Express.

This post has the part number needed.

Copy / Paste from above link.
"The part number: BWD S5613 stands for Borg Warner, part number S5613."


I would assume that your location "down under" would have the same part number. I find it hard to believe that Ford Motor Company would only use the same basic engine in only one vehicle.
 
The equivalent NAPA solenoid ECH ST421 lists these vehicles as applicable:

Ford Crown Victoria 2001 - 2005
Ford Marauder 2003 - 2004
Ford Mustang 2001 - 2001
Ford Truck E150 1/2 Ton Econoline - Van 2001 - 2001
Ford Truck E250 3/4 Ton Econoline - Van 2001 - 2001
Ford Truck Excursion 2000 - 2001
Ford Truck F150 1/2 Ton - Pickup 1995 - 1996
Ford Truck F150 1/2 Ton - Pickup 1999 - 2001
Ford Truck F250 3/4 Ton - Pickup 1995 - 1995
Ford Truck F250 3/4 Ton - Pickup 1999 - 1999
Ford Truck F250 Super Duty 3/4 Ton - Pickup 1999 - 2001
Ford Truck F350 Super Duty 1 Ton - Pickup 1999 - 2001
Ford Truck F53 1995 - 1996
Lincoln Town Car 1998 - 2001
Mercury Marauder 2003 - 2004
 
Thanks for the responses but it appears I can't get the solenoid in Aus, may need to have one shipped in, but will do a little more research before commiting to that option.

Just BTW, for decades Ford Australia manufactured it's own unique cars and engines in this country and none of the cars Mike listed were sold here.
 
Thanks for the responses but it appears I can't get the solenoid in Aus, may need to have one shipped in, but will do a little more research before commiting to that option.

Just BTW, for decades Ford Australia manufactured it's own unique cars and engines in this country and none of the cars Mike listed were sold here.

A quick search on Rockauto shows the 2005 Crown Vic starter solenoid is about $36US delivered to me across the Tasman, must be similar to Sydney.
 
A quick search on Rockauto shows the 2005 Crown Vic starter solenoid is about $36US delivered to me across the Tasman, must be similar to Sydney.

Thank you Craig! Rockauto didn't appear in my google searches so I appreciate the suggestion. Same quote to have it delivered to Sydney which is a good deal so I have placed an order.
 
I've been struggling to understand the operation of these starters. Not having much luck finding any info on the actual design of the skytec starters.

To clarify my understanding can anyone confirm the following:

The skytecs do not have a spring-type Bendix drive that moves the pinon forward into the ring gear. They use an electromagnet and a fork to accomplish the same thing.

They also do NOT have a contactor as part of the same plunger on the pinon actuator that prevents the starter from spinning until the pinon is completely engaged with the ring gear.

If the pinon actuator was to fail you would still hear the starter spinning during starter engagement.
 
...
They also do NOT have a contactor as part of the same plunger on the pinon actuator that prevents the starter from spinning until the pinon is completely engaged with the ring gear.

If the pinon actuator was to fail you would still hear the starter spinning during starter engagement.

They DO have a contact under the two large terminals at the back/top/end of the solenoid.

In the case of the XLT, PM/LS, HT versions, if the solenoid plunger (white or black nylon thing) were to fail and become disconnected from the see/saw/fork arrangement, you would hear the starter spin because the solenoid would close the contact and allow current to flow to the starter motor.

However, we've seen a different failure mode with these solenoids -- the plunger becomes stuck partway or binds during movement and the contacts remain open; all you hear is the "clunk" of the Starter Relay (not Starter Solenoid) when you turn the key/push the button...
 
Thanks very much Brian.

If the firewall mounted solenoid we replaced doesn't resolve the issue we know where to look.

I drilled out the rivets on the old relay and there was some pitting on the contacts but not what I would consider "excessive".
 
Follow up.......

This past weekend on a tailgating trip to Ames, the LS starter spun slowly again. So I pulled the solenoid, got a free replacement and put it all back together. Really an easy repair. Easier than on a 2005 Crown Vic! ;)

Initial solenoid went 1865 hours, this BWD S5613 went about 635 hours. I'll not complain. It was a good chance to clean contacts as well.

Maybe it is worth changing every 10 oil changes or so........
 
This past weekend on a tailgating trip to Ames, the LS starter spun slowly again. So I pulled the solenoid, got a free replacement and put it all back together. Really an easy repair. Easier than on a 2005 Crown Vic! ;)

Initial solenoid went 1865 hours, this BWD S5613 went about 635 hours. I'll not complain. It was a good chance to clean contacts as well.

Maybe it is worth changing every 10 oil changes or so........

Thanks for the update Pete! I had a cracked solder joint that plagued my starts with clicks from Hobbs 12 to 180 hrs.

For others reference, there is also a "Standard Brand" number SS754 for this solenoid. Rockauto has the best price (~$20) but O-Reillys (~$40) was purchased for time sensitive flight. Genuine Ford Part Number F6VZ11390A . . . maybe useful for non USA locations

I am beginning to ponder a personal parts department for inventory management. :(
 
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Thanks for the update Pete! I had a cracked solder joint that plagued my starts with clicks from Hobbs 12 to 180 hrs.

Has anyone attempted to re-flow the solder pool?

I'm thinking the Weller pencil type with the wide tip (3/16" or 1/4") would work ... or break out Dad's Weller "Space Gun" (8250A), that would definitely work :)
 
For those with cracked solder joints, it would be a good idea to flow a piece of shielding braid from a multi-conductor cable into the solder pool to help reinforce it. This is the same idea as fiberglass+resin composite.
 
To jump or not to run a jumper

A tech friend advised me that I should not jump the B+ and S terminal on my Sky Tec 149NL and use this in the starter enable/disable switch to turn off the circuit manually so there was not a possibility of the starter engaging when the engine is running. I've researched this and can not find any information. I do use a switch to disable the starter. Also using VPX. Is there a concern of solenoid closing at the wrong time? The VPX does have a start circuit that turns off positive 12 volts over 600 RPM. Is this a concern?
 
This past weekend on a tailgating trip to Ames, the LS starter spun slowly again. So I pulled the solenoid, got a free replacement and put it all back together. Really an easy repair. Easier than on a 2005 Crown Vic! ;)

Initial solenoid went 1865 hours, this BWD S5613 went about 635 hours. I'll not complain. It was a good chance to clean contacts as well.

Maybe it is worth changing every 10 oil changes or so........

Having the same issue and assumed the PC680 needs to be replaced (6 years old), why does the solenoid cause slow cranking?
Figs
 
A tech friend advised me that I should not jump the B+ and S terminal on my Sky Tec 149NL and use this in the starter enable/disable switch to turn off the circuit manually so there was not a possibility of the starter engaging when the engine is running. I've researched this and can not find any information. I do use a switch to disable the starter. Also using VPX. Is there a concern of solenoid closing at the wrong time? The VPX does have a start circuit that turns off positive 12 volts over 600 RPM. Is this a concern?

The double solenoid for starting was an issue found back in the RVAviator days and Vans posted it in a newsletter. If it applied then, it applies now. A historian can quote date.

The explanation IIRC was that the starting motor solenoid would get energized (back fed) by the PM motor as the RPM accelerated rapidly during starting. Then it would not release. The firewall solenoid will release.

Having the same issue and assumed the PC680 needs to be replaced (6 years old), why does the solenoid cause slow cranking?
Figs

High resistance.

Has anyone attempted to re-flow the solder pool?

I'm thinking the Weller pencil type with the wide tip (3/16" or 1/4") would work ... or break out Dad's Weller "Space Gun" (8250A), that would definitely work :)

No way a tiny soldering iron would do this job. Besides, there is a rivet that is supposed to hold that terminal firmly, if it comes loose (mine did) there is a bending moment on the solder joint. I can not honestly say, 100%, that it was not builder induced. :eek:

Being stranded at a desolate airport was not worth the $20-40 savings. Although worth having a free spare until . . . . nah. Not going to happen.

Hmmm - - 10 oil changes sounds like a good plan. :D
 
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For those with cracked solder joints, it would be a good idea to flow a piece of shielding braid from a multi-conductor cable into the solder pool to help reinforce it. This is the same idea as fiberglass+resin composite.

I had the same thing happen at about 300 hours. I was on the ground in Arkansas all loaded up for departure and hit the switch - nothing. I suspected a loose wire on the solenoid coil circuit, and knowing where it was mounted, I held the starter key in the crank position while tapping my right foot on the firewall close to the heater duct, and BINGO, she cranked up. I replaced the solenoid when I got home. On inspection it was obvious the rivet holding it together was loose.
 
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