Motorhome Won’t Start: No Power To Ignition Switch (Guide)
It can be a scary feeling. After packing up after a nice night boondocking and buckling in, you are ready to hit the road again. Yet, when you turn the key and nothing happens, all the good nature just drains out of you as you realize you are not going anywhere anytime soon.
When you experience this situation and feeling, your first thought should be to check your ignition solenoid. If it has malfunctioned then anything that relies on the ignition switch to function, won’t turn on. That includes your motor. If you do not hear the click when you turn your key, that is the part that has malfunctioned.
To learn more about what to do when your RV doesn't start, just continue to read our article. it has the information you need to solve these issues and get back on the road quickly again.
Troubleshooting a Motorhome That Won't Start
The advice we give for all repairs is to start with the easiest and simplest parts to see if they have malfunctioned in some way. By starting with the easiest, you have simpler fixes and you may be able to do them yourselves and get on the road quicker. Also, you should save money if those are the problems.
One place to look would be the chassis battery disconnect switch. If it springs back into the on position after switching it to off then that may be your problem. The switch may be faulty and would need to be repaired or replaced.
If that is not the problem, then you can check your ground situation. It is said that 95% of all electrical problems are due to a bad ground. A simple test with the right electrical meter will help you identify this problem and where it is located.
If it is the solenoid, like we first mentioned above, then you would probably have to have it replaced. another place to check is your fuse box. You may have one or two of these and the fuse working with your ignition switch may have blown.
If you carry extra fuses, you can replace the bad one with a new one. Then your troubles may be over. The final place to check would be your batteries. If they have lost power, you won’t start. You should check to see if anything was on that drained the battery of its power and turn it off before recharging.
Motorhome Engine Battery Dead
When it comes to RVs, battery designs are different from regular vehicles. There are usually two batteries and they have different purposes and different power designs. The first is your regular engine or start battery. This device is designed to handle large amounts of current for a short period. Like starting your engine.
The house battery is designed to handle your RV's appliances, lights, and other electrical outlets, etc. It works with a steady amount of power and for long periods. The two batteries are not interchangeable so if your start battery dies, you cannot replace it with your house battery.
There are different situations like will drain your battery of power leaving you without the ability to start your motor and get moving. The first is the slow drain and there are several sources for this:
- Headlights or parking lights left on by mistake
- Exterior lights left on
- Engine was left in aux mode
- Audio systems left on
- Forgetting to turn on your generator when you parked
The second source for a dead battery is the low charge that has gone on for too long. This has to do with the crystals inside your battery. They break down when the unit is charged and then they disappear. But if you have the battery on a low charge for a long period, then the crystals do not break down and ruin your battery.
The third source for this problem is too high of a charge. This is where you overcharge the battery burning off some of the water inside the device. Batteries are 64% water and a very high charge will eliminate some of that water and overheat the battery ruining its components.
Finally, your battery will lose power because it is old and weary. When they get old, they will lose their power quicker, even with proper maintenance. The solution to all of these dead battery situations is to find a nice person who will jump your start battery like you would jump a car battery.
Or call your Roadside service organization and have them come out and help you.
No Power to Ignition Switch
When it comes to older RVs, the manufacturers had kept the ground cable exposed. This means that it is and was vulnerable to the elements. This situation allowed for corrosion to build up and the ground cable needs to be cleaned.
A good wire brush should handle that chore. Just make sure to remove the ground cable before cleaning it. If it isn’t the ground cable then check the relay or solenoid valve. They may not be placed in the same spot or near each other.
One could be behind the batteries and the other may be near the chassis fuse box or placed in your dash. To help identify the problem, you will need a 12-volt test light. They are not expensive and they let you know where the power is and where it isn’t.
Sometimes, there may be something blocking the solenoid terminals. To identify and fix this issue, you need someone watching the ignition power with the key turned on. You can then tap the solenoid and see if the power returns.
Or check your AUX boost switch if you have one and see if it is working. The boost switch should be located in your dash and its job when activated, is to transfer power from the house battery to your start battery.
Don’t forget to check your solenoid fuse to see if it has burned out or not. There is usually only one fuse for two solenoids on some RV models.
RV Ignition Switch Problems
There is one simple issue that you should consider when you are diagnosing your ignition switch problem. RVs tend to vibrate a lot as they move down the road. When this continues for long periods, your wire connections can become loose.
This can be your problem so check those connections first. If it is the source, you should be back on the road in no time after tightening those connections. One thing that is not the problem will be your starter solenoid. That is attached to your starter and does not influence your ignition switch.
It may be the relay that is the source and that means you should bypass that part and see if it is the problem. If it is you would need to replace the relay. Of course, you shouldn’t ignore the different fuse boxes. You never know when one of those will blow and cause all sorts of problems for you.
If these sources are not the problem then you can check the alternator exciter wire. If that wire malfunctions, it can cause problems for your ignition system and switch. This may be a long shot as when this wire malfunctions, the engine usually does not turn off.
Before you get the repairman to help you solve the problem and to avoid one of those embarrassing moments, check the batteries first. On some models that batteries are placed up and out of the way in a difficult-to-access spot.
That location makes it hard to see the casing. Often when you have an ignition switch problem the source is a cracked or broken battery casing and all the acid and water drained out. Replace the batteries and your problem should be solved.
RV Ignition Solenoid
Three common issues arise when your ignition solenoid is acting up or malfunctioning:
- 1. It is overheating - the solenoid will heat up when there is power running through it. That is normal especially when you have a lot of batteries feeding your appliances and other electrical needs.
If the solenoid is too small it will abnormally heat up and cause your rig some problems. Make sure to check the wiring to see that none are loose as that situation will cause overheating as well.
Don’t remove the solenoid as you won’t be able to start some RVs. Instead, replace it with a bigger one that can handle the heat.
- 2. Dead battery cells - this happens when there is not enough water in the device. When your battery is low on water, it stops charging but the solenoid keeps sending the battery power. This means that one or the other will get damaged when the battery is not charging up.
Also, some battery banks have cells that die, and when they do you need to replace them. The dead cells allow the battery to draw lots of power and damaging parts connected to it, like the solenoid.
To avoid these two situations maintain your batteries regularly. Plus, clean the terminals, etc. to get rid of any power stopping corrosion.
- 3. Faulty solenoid - this is a common occurrence as parts break down, wear out or get old. Plus, they can get damaged which interrupts their normal functions. To test your solenoid, simply take it out and attach it to a terminal, Then use a voltmeter to see what kind of current or how much is coming through the solenoid.
If the current is fluctuating then the solenoid is malfunctioning and needs to be replaced. If you get a no current reading then the solenoid is dead and also needs to be replaced. All you have to do is make sure to get the right solenoid for your rig. That isn't that hard to do.
Motorhome Engine Turns Over But Won't Start
There are several sources for this problem. Some are related to the fuel you use in your RV. For example, if you have stored your RV for the winter, old fuel may not ignite as it has deteriorated. This is common with modern reformulated gasoline. A fuel stabilizer needs to be added to your tank to avoid this problem.
Another source for this problem is a lack of spark or what is called usable spark. Little to no spark will not create the power needed to turn over all the parts in your engine. Or it could be that your engine is not getting enough usable air to fuel mixture.
If you pumped your gas pedal too much, you may have flooded the engine. This is a very common situation when people are in a hurry and want to get going quickly. When you flood the engine you have to wait for a bit to let the fuel clear out before it will start again.
To clear up the no spark issue, you will have to test it, and if there is no spark you have problems in your ignition system that need to be fixed. Then for the fuel-air ratio, you need a fuel pressure gauge and if there is no pressure the problem will be your pump.
Sometimes knocking the pump will loosen it up and your RV should start again.
Some Final Words
The key to solving RV electrical problems is if you do not know anything about RV electrical systems, etc., then DO NOT TOUCH THEM. You never know when you make a simple problem worse by fiddling with parts you know little to nothing about.
It may cost you more but let the pros handle these issues so the fix is correct.
