Perkins 4 108: “Emergency” Starting Without Ignition/Panel

[HardTAC]

We’re stuck in a (somewhat) remote location and it’s clear my ignition circuit is shot. Or maybe it’s wiring leading to it. Anyway, no response to turning the key. And, I can’t find any voltage getting to the back wires of the ignition. Engine instrument panel unresponsive. And yet, my batteries are fine, and all other DC systems are working fine.

I’m 3-4 days away (sailing) to get back home. There, I can work with my mechanic to fix/upgrade things. In the meantime, I just need to be able to start my Perkins to enter/exit harbors (and transit the Cape Cod Canal) along the way.

Does anyone know how (with detailed instructions) I could apply 12v to the starter motor to fire the old girl up? I’m handy, but don’t have much experience around around engines.

Thanks for any immediate ideas!

My wife thanks you too!!

Todd

[masonc]

Originally Posted by HardTAC

We’re stuck in a (somewhat) remote location and it’s clear my ignition circuit is shot. Or maybe it’s wiring leading to it. Anyway, no response to turning the key. And, I can’t find any voltage getting to the back wires of the ignition. Engine instrument panel unresponsive. And yet, my batteries are fine, and all other DC systems are working fine.

I’m 3-4 days away (sailing) to get back home. There, I can work with my mechanic to fix/upgrade things. In the meantime, I just need to be able to start my Perkins to enter/exit harbors (and transit the Cape Cod Canal) along the way.

Does anyone know how (with detailed instructions) I could apply 12v to the starter motor to fire the old girl up? I’m handy, but don’t have much experience around around engines.

Thanks for any immediate ideas!

My wife thanks you too!!

Todd

Jump 12v to the starter solenoid from the positive battery connection on the starter, that will turn over the engine. It will probably need 12v to the fuel solenoid, or jam it open mechanically. If it is getting fuel and turns over, it'll start and run.

[NSboatman]

I presume you have the Lucas starter, but regardless if starter type, there will be a starter solenoid near the starter (small cylindrical thing about 2" in Diana that has both the light gauge wires from your ignition circuit, and the heavy gauge wire from the positive terminal of the battery on one side, and a short, heavy gauge, jumper to the starter on the other).

All you need to do is energize this solenoid with +12v (usually it gets the -12v from the bolted case connection on the engine). You can run any old piece if temporary wire from the battery + terminal and jab it in the small positive terminal on the switch side if the starter solenoid; and you'll bypass the entire ignition circuit and engage the starter.

I used to have a small mini-jumper cable with small alligator clips (commonly called test leads) made up and permanently coiled and taped next to the starter on my old boat for exactly this reason. Handy to have a set of car jumper leads on board too for this sort of thing.

If it's a fault in the ignition circuit (likely) then you may also have luck with a simple screwdriver across the lift gauge terminals on the solenoid as well. This also bypasses that circuit.

Good luck and let us know how it goes!

Bg

[NakedCity]

Seems like you must have a smart phone or other internet access.
Go to Youtube and search "How to jump a starter with a screwdriver" and you will learn more than you ever wanted to about starters

[travellerw]

Ok.. Lets see if I can give you some detailed instructions.

1. Get a temporary piece of wire (16 guage min). Long enough to go from your starting battery to the port side of the motor.
2. Locate the starter solenoid. It should look like this:

NOTE some new starter motors actually had the solenoid on the starter itself. If so your starter will look like this:


3. Take your temporary piece of wire and connect it to the positive side of the battery. Then momentarily touch the other end of the wire to the small stud on the solenoid (its the stud that will have the small wires going to it). The starter will engage and spin the motor over. Stop touching the wire to the small stud once the motor fires.

[masonc]

Originally Posted by HardTAC

We’re stuck in a (somewhat) remote location and it’s clear my ignition circuit is shot. Or maybe it’s wiring leading to it. Anyway, no response to turning the key. And, I can’t find any voltage getting to the back wires of the ignition.

I think a safer and simpler way would be to diagnose your switch issues. Take a meter, attach the negative solidly to battery negative, and test the positive. It should give you battery voltage, probably 12.5V or so.

Now test the back of the switch. You should have a battery positive feed to the switch. If you don't, find out why. On the drawing I found, there's a #10 red coming from the ammeter, check it there. Follow it back to the starter motor which is typically the distribution post for the engine.

If you find the source fo the problem, it will give you full functionality, and you will understand your wiring better for the next time you have problem.

[Cheechako]

BTW, The plastic multi pin wire connector, usually at the back of the 4-108, can get corroded inside and cause that problem. No power to the engine or panel at all. Been there done that.... The connection has maybe 8-12 pins inside...

[gjordan]

It has been mentioned that you might need to energize the fuel shut off solenoid. I believe that unless Perkins has changed, you only need power to the solenoid to stop the engine, so if you get it running, you need to make sure you have located the stop solenoid and how to mechanically pull it to stop the engine. It is easy to do but a lot easier if you have figured it out when the engine is cool and you are not in a hurry. Good Luck and a safe trip home. _____Grant.

[masonc]

Originally Posted by Cheechako

BTW, The plastic multi pin wire connector, usually at the back of the 4-108, can get corroded inside and cause that problem. No power to the engine or panel at all. Been there done that.... The connection has maybe 8-12 pins inside...

I'd take a bet that's your probem. Open the connector, check for 12V on the red wire of the connector half connected to the engine. Clean and reconnect. Problem solved.

[Cheechako]

Originally Posted by masonc

I'd take a bet that's your probem. Open the connector, check for 12V on the red wire of the connector half connected to the engine. Clean and reconnect. Problem solved.

Yeah and mine did that in a clean dry boat. Go figure.
OP: you should learn how to jump that starter with a big screwdriver anyway though.

[keithw88]

I think it worth mentioning that "jump" is what you will do when you bridge the heavy-guage positive wire to the negative wirh a screwdriver. You are putting a lot of current through the screwdriver, resulting in at least some sparks. A couple of times I have had to pull the screwdriver away very quickly as those sparks have started to weld everything together. I have had to tug the screwdriver away quite firmly and you could see areas of melted metal where the sparks flew.
If you aren't quick enough and the weld is too solid to break, your problems would multiply; at least the death of the battery, at worst a serious electrical fire.

[parkstone bay]

If you are playing with jump leads, shorting terminals with screwdrivers etc., for Heaven's sake, please keep hands, clothing (especially neckties) , jewelry (including watch strap), well clear of rotating bits like the starter motor and the flywheel.

[Cheechako]

Originally Posted by keithw88

I think it worth mentioning that "jump" is what you will do when you bridge the heavy-guage positive wire to the negative wirh a screwdriver. You are putting a lot of current through the screwdriver, resulting in at least some sparks. A couple of times I have had to pull the screwdriver away very quickly as those sparks have started to weld everything together. I have had to tug the screwdriver away quite firmly and you could see areas of melted metal where the sparks flew.
If you aren't quick enough and the weld is too solid to break, your problems would multiply; at least the death of the battery, at worst a serious electrical fire.

[michaelratinter]

I use a quarter (US 25 cent coin) to jump the large post on the starter solenoid to the smaller post on the starter solenoid. The sparks scare the crap out of me but it works.

+1 on finding the stop solenoid before starting the engine.

[donradcliffe]

The starter solenoid has the small terminal for energizing the solenoid, plus the big terminal with the red wire from the battery. Those are the terminals you need to jump across, not the two big ones.

On all my engines, I install a permanent jumper wire with a push button switch in the middle, which is mounted on the outside of the engine compartment. If the ignition circuit fails, pushing the button is a lot faster and safer than finding a screwdriver or wire and opening up the engine compartment.