Starter fails to engage

[gselliott]

Intermittently, the starter fails to engage in my Sightseer 33C, Ford Triton V10 chasis. My chasis battery is fully charged (12.7V) and the terminals and connections have been cleaned and tightend. When I turn the key to ignition, everthing is normal. However, sometimes when I advance the key to start, the starter will fail to engage. If I persist holding the key in the start position, the starter will eventually engage and the engine starts normally. Sometimes when I advance the key to start, the starter will engage and the engine starts normally.
HERE IS MY QUESTION/CONCERN: I have a Victron battery monitor for both the coach (lithium ion) and chasis batteries (lead acid). I have noticed that when I turn the key to ignition, there is a 15 to 20 amp load on the COACH batteries and this continues when I advance the key to start. This happens even though I have not engaged the battery boost and the chasis battery is fully charged. I am thinking that there should not be a draw from the coach batteries unless I engage the batter boost. And, I am suspicious that one of the solenoids that control energy flow is possibly preventing energy from going to the starter.
Any ideas or suggestions will be appreciated as I am not sure whether I have a chasis (Ford service center) or coach problem (RV repair).
Thanks

[Morich]

I would not be too concerned with the amp draw as it may be normal.One point about the coah and start connection without pushing the boost switch ? The solenoid that does that connection also has a connection to what is often called ignition run or something of that sort. A point which is hot when ignition is on? Turning the switch on sends power down the same control wire as when we push the boost switch.

One situation is when we want to "boost" the start battery when it is weak and the other lets power from the RV engine alternator do some charge of the coach batteries as we drive. So it is a two function item.

But for cranking, I don't feel that system is involved.

But there are lots of auto type things that may be about to fail totally. One is the ignition and key as there are lots of switches and other things that have to be right.
Older cars had a pretty simple setup. When we turned the key a signal was sent down to the starter solenoid,it closed and we heard the starter crank the engine.
On those, the on again/ off again cranking was often jsut aworn out set of contacts on the starter solenoid or sometimes the key was worn out.

Newer have all kinds of other things involved before we can crank. Gear position? park brake? Seat belt warning, etc are a start as well as things to keepfolks from hot wiring the car! So I'm thinking it is almost certain to be in the automotive end of things, not the RV.

Maybe do a bit of testing to see what it may do? If it is bad contacts in the solenoid, if you hit it and it does nothing, try turning the key and repeat it several times as the solenoid contacts may hit in a better spot on the later tries.

[gselliott]

Richard,
Thanks for your quick feedback. You suggested repeated turning of the key to start. I have done that and it sometimes works after 5 - 10 tries. Anyway, it sounds like you are favoring a chasis problem related to starter or starter solenoid. The solenoid is integral to the starter, so I cannot just replace the solenoid as a test. I am about ready to take it to a Ford/truck service center.

[creativepart]

We'd love to know what year your Sightseer is - it's not in your post, nor in your profile.

If it's a 2020 that's one thing if it's a 2002 that's another.

So please fill us in and try to remember to always do that. OR better yet put it in your signature in your Profile so we'll see it on every post you make.

[Morich]

Originally Posted by gselliott

Richard,
Thanks for your quick feedback. You suggested repeated turning of the key to start. I have done that and it sometimes works after 5 - 10 tries. Anyway, it sounds like you are favoring a chasis problem related to starter or starter solenoid. The solenoid is integral to the starter, so I cannot just replace the solenoid as a test. I am about ready to take it to a Ford/truck service center.

I can appreciate where you are and the doubts you have on what is going on. We went through a major amount of trauma trying to get a 2014 Ford focus figured out. It was one of the few times when I have ever bought extended warrenty but this car had " hit a mail box" and had what was described as minor damage. But it was one that we could tow and was really a car I liked for my use, so went with the idea of the warrenty giving me protection.
It would start fine most of the time but then other times it might take 10-15 turns of the key to get it to crank. Once it cranked it would start right away but always gave the bad feeling we would get stranded!

Three different Ford shops and numerous times, with lots of effort and nobody could actually pin down the problem. After four hours of setting, your odds were good but after setting overnight, the odds went down to 50-50 but the battery was always good. All kinds of things like TCM, PCM, ignition switch and key and even down to changing the transmission after they broke a part off the TCM that went down inside, were getting nowhere, so we bit the bullet and sold it.

Life was getting too short to keep fighting it, even on their time!