free website stats program Engine Does Not Start | Harley Davidson Forums

Engine Does Not Start

Not open for further replies.


BOT Machine
Sometimes when you press the start button, you get a surprise and nothing happens.

When that happens here's a few things to check out to find the cause using common sense and a few hand tools.

First here is to look for any obvious problems like broken/disconnected or burnt wires. You can also get a grounded wire on the engine that melted from the heat of the engine that will blow a fuse or melt the connection to the system in question.

1. First and most common thing here is the battery condition if it is charged or not and holding at least 12 volts. Electrical ECM's ( the brain of the bike) need at least 9+ volts to fire the bike up.)

2. Most no start conditions are usually a result of a poor connection to the battery. Remove, wire brush and reconnect the positive and negative cables on the battery to be sure you have a good connection. Don't take it for granted that if it looks OK that it is. It only takes a little corrosion or a cable clamp bolt that isn't tight enough to cause a no start condition.
Generally in a no start condition caused by a loose or corroded terminal end, if you hold the start button depressed for a few seconds, the bad terminal will get hot to touch, but to be sure, clean them both anyway.

3. To check if it is the starter or the solenoid, use a piece of 14 gauge wire connected to the positive of the battery and remove the small green wire from the solenoid. After it is off, the direct wire from the battery should activate the solenoid and crank the engine if all here is OK. Doing this when you touch it to the terminal that the green wire came off. The bike should crank.
You'll get a small spark here so don't jump This checks if you are loosing the power from the starter relay to the solenoid.

4. You just checked the condition of the starter and the solenoid itself. If it cranked and the solenoid activated with what you have done, the problem is likely in the wiring or the starter relay itself. The contacts in the relay can become burnt after numerous starts and cause an intermittent condition also. You can shortcut here and substitute a starter relay of good quality to check it over. They usually don't go bad too often and are inexpensive to replace. A relay at the auto parts store will work as well as a genuine HD part.

If you wish to check out the relay while it is still on the bike and connected, you can use a wire to bridge the terminals on it that correspond to terminals 30/51 which is the input of the solenoid power (12V) and terminal 87 which is the power to the solenoid. This eliminates the solenoid from the system by bypassing it and should crank the engine when you do this.

After this, you have to get into the wiring on the bike and a service manual is needed here to trace point to point and check voltages.
Remember however if you check a voltage and get what you were looking for that sometimes amperage isn't sufficient to activate a circuit. It only takes one strand of a wire to give you a voltage reading but the complete wire in good condition to deliver the amperage needed to properly run a circuit. Possible causes for this would be a broken wire inside the insulation from movement.

No start conditions are easily traced to a defective part with little or no experience in most cases with a little help if you are not sure.

If in doubt of the battery condition, you can have a load test done at most auto parts stores for free.

This covers some of the basics for the electrical system problem areas that arise and should help in the basic trouble shooting of a no start condition.
Last edited by a moderator:
Not open for further replies.