Battery boost solenoid location 2003 Adventurer 33V

[steffanfay]

I had the same issue experienced in this old thread: Step Alarm Fuse

It's a failure in the "Run Only Power Source" circuit.

These were my symptoms:
. Step alarm 5A fuse immediately blows on ignition key turn, step operation good.
. 18 ohms to ground on the load side of the step alarm fuse with ignition off - not good.
. Jacks beeper and alarm light dead, jack control panel and operation good.
. Rearview camera dead (inline fuse good, temporarily rewired to house power, then good.)
. Coach heater blower motor dead.
. Alternator does not charge house bank - no bueno when I have 1,300 miles to drive starting the next day. Temporarily rigged an aux battery/inverter to keep house bank charged while traveling.
. Battery boost operation good.

I started going through the remaining circuits mentioned upthread:
. Coach heater switch removed, does not resolve short.
. Battery boost switch removed, bingo, short resolved.

Before I go hunting for it, can anyone tell me what that solenoid looks like, and/or where it is located? I plan on replacing the switch with something generic and the solenoid with the NAPA equivalent mentioned in the old thread.

Cheers,
Steffan
2003 Adventurer 33V

[creativepart]

Here's a link to the online wiring diagram for the 2003 Adventurer 33V:

https://www.winnebago.com/Files/File...33v_wiring.htm

On the older shorter coaches it could be under the "hood" near the engine OR sometimes it's directly behind the 12v resettable breakers in the compartment next to the battery bank.

Here's a wiring diagram from the link above showing the solenoids but not where they are located:

[creativepart]

Look for a sticker that reads as this one shown and the solenoids will be behind a removable panel:

[tderonne]

Under the steps. As shown in the diagrams linked above,

[Morich]

I would suggest disconnect wire LR from the small center post on the solenoid and retest before changing it!
Of all the items mentioned in your testing the solenoid is one which is very simple and the resistance test to ground may simply confuse you as the coil of the solenoid is connected to ground! The resistance you are seeing may only be the coil???

A second item to make me question is that you say the boost function works? The thing that makes the boost function work is the solenoid, so that would be saying it is working fine but bad???
Seems to be a conflict in there somewhere?

[steffanfay]

Originally Posted by Morich

I would suggest disconnect wire LR from the small center post on the solenoid and retest before changing it!
Of all the items mentioned in your testing the solenoid is one which is very simple and the resistance test to ground may simply confuse you as the coil of the solenoid is connected to ground! The resistance you are seeing may only be the coil???

A second item to make me question is that you say the boost function works? The thing that makes the boost function work is the solenoid, so that would be saying it is working fine but bad???
Seems to be a conflict in there somewhere?

Yes, the last thing I expected was for the boost function to work, but I actually used it on a cold Saturday morning before I went through the troubleshooting steps today. I have a Victron BMS and saw the voltage on the starter battery go above 13v when I pushed the switch. The starter span quicker as it always does on boost. I'm loathe to try that again until I really figure out what's going on though. I'll try as you suggest with the LR wire first.

[steffanfay]

Originally Posted by creativepart

Look for a sticker that reads as this one shown and the solenoids will be behind a removable panel:

Ha, yes. I've seen that panel before. I forgot it was there! Thank you so much.

[Morich]

I'm familiar with trying to get the breaker panel out and get to the solenoid, so I might suggest a different idea before doing the hard part?

Understanding how simple this solenoid really is may help to point to saving some work?
It is only a coil of wire making an electromagnet which has a center shaft of metal with the large contacts like large washer at the end of the shaft. Nothing fancy but just a coil to move the shaft?
When it moves the "large washer" clucks up to touch the big lugs on each side. The normal failure is that these contacts gets a pretty big arc each time we start the engine and the tend to get burned and corroded fairly often! then they don't make contact and the coach batteries don't charge as we drive.
Sometimes the coil probably burns out and it doesn't move? So the main failures are the contacts don't move when 12volt is put on the small wire or the contacts are corroded and don't make.

Before digging to get access, I would want to pick a quiet day or have a helper push the switch while I listen if it moves as it is a big heavy set and we can often hear it clunk!
If it moves when we push the boost switch, that is about all the coil does!

But I might also point out that your test of watching the coach and seeing it match up with chassis battery voltage is also telling you the solenoid is doing it's job!
for testing the solenoid, I try not to go to it but if the batteries are close together, I look at the chassis and coach voltages and normally there is some difference. Then when I start the engine or push and hold the momentary switch, if they match, I see them connected and call the solenoid good!

Just looking for ways to avoid work?? But it may point me to something harder to figure out!

[steffanfay]

Originally Posted by Morich

I'm familiar with trying to get the breaker panel out and get to the solenoid, so I might suggest a different idea before doing the hard part?

Understanding how simple this solenoid really is may help to point to saving some work?
It is only a coil of wire making an electromagnet which has a center shaft of metal with the large contacts like large washer at the end of the shaft. Nothing fancy but just a coil to move the shaft?
When it moves the "large washer" clucks up to touch the big lugs on each side. The normal failure is that these contacts gets a pretty big arc each time we start the engine and the tend to get burned and corroded fairly often! then they don't make contact and the coach batteries don't charge as we drive.
Sometimes the coil probably burns out and it doesn't move? So the main failures are the contacts don't move when 12volt is put on the small wire or the contacts are corroded and don't make.

Before digging to get access, I would want to pick a quiet day or have a helper push the switch while I listen if it moves as it is a big heavy set and we can often hear it clunk!
If it moves when we push the boost switch, that is about all the coil does!

But I might also point out that your test of watching the coach and seeing it match up with chassis battery voltage is also telling you the solenoid is doing it's job!
for testing the solenoid, I try not to go to it but if the batteries are close together, I look at the chassis and coach voltages and normally there is some difference. Then when I start the engine or push and hold the momentary switch, if they match, I see them connected and call the solenoid good!

Just looking for ways to avoid work?? But it may point me to something harder to figure out!

Thanks for the suggestions! I appreciate the sentiment. I have the boost switch removed and I know that if I reinstall it I'll blow that 5A fuse again, so I can't/don't really want to do that. I did cut the shore power, start the engine and confirm that the house bank is not charging (see screenshot). So I figure I'm in for a new solenoid anyway.

I'm not scared of the job. I've already had to uninstall & reinstall the water heater to replace the outflow check valve, replace the turn signal stalk to fix the cruise control, and uninstall & reinstall the windshield washer fluid reservoir to get semi-solid mat of gunk that was clogging the pump inlet. And that's far from a complete list

I guess I'm a glutton for punishment. Why else did I buy a 20 year old coach?

[Morich]

Yes, I see the reasoning on thinking the solenoid is not working. And it does look like time to get to it to test a bit. One point to keep in mind is where the monitor may be picking as a test point? I've never sorted down that far on one with monitor but I never like to trust things I don't know about!
It could be right or it could be fooled if the connection it uses is a bit dirty? Or it could be that the solenoid is closing and making contact but the cable from the solenoid to the batteries is a bit dirty.
We just have to be aware and not take the first answer we get at times and battery problems are some of the most confusing if we are sleeping a little too much!

Are you aware of the way Winnebago marks battery cables as a help to sorting which goes to what? The tape has a bad habit of falling off or not there if the cable has been changed but the code may help?


Good luck on the chase!
The only thing that works full time on an RV is the owner!

[steffanfay]

Originally Posted by Morich

Yes, I see the reasoning on thinking the solenoid is not working. And it does look like time to get to it to test a bit. One point to keep in mind is where the monitor may be picking as a test point? I've never sorted down that far on one with monitor but I never like to trust things I don't know about!
It could be right or it could be fooled if the connection it uses is a bit dirty?

I just installed the monitor last week, after using the same system on my boat for a few years. The shunt goes in the house negative inches from the post. I crimped new terminals on when I installed it and the cable looked fine. The fused positives go straight to the posts, so they are good too. It's about the one thing I for sure trust in the electrical system.

Originally Posted by Morich

Or it could be that the solenoid is closing and making contact but the cable from the solenoid to the batteries is a bit dirty.
We just have to be aware and not take the first answer we get at times and battery problems are some of the most confusing if we are sleeping a little too much!

That's possible, I'll check and clean the cables while I'm in there. Thanks!

Originally Posted by Morich

Are you aware of the way Winnebago marks battery cables as a help to sorting which goes to what? The tape has a bad habit of falling off or not there if the cable has been changed but the code may help?

Thank you!

Originally Posted by Morich

Good luck on the chase!
The only thing that works full time on an RV is the owner!

At least this is more accessible than the back of the water heater. No yoga required. Thanks again.