# 6601s trick starting



## carfarm (Feb 19, 2016)

*New Holland 6610s trick starting*

I have a NH 6610s 2000 model that has a trick to starting. I have to jumper a positive lead to the fuel shutoff solenoid terminal and she fires right up. Once its started, I can remove the jumper. I haven't spent much time troubleshooting, thought maybe it could be the transmission safety switch. It turns over with or without the jumper wire in place. I have checked the fuses, they seem to be all good. Any ideas.


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## HarveyW (Sep 15, 2014)

Hello carfarm,

Welcome to the tractor forum. 

Try jumpering the safety switch wires to determine if this is your problem. 

I have a small Kubota with a fuel cutoff solenoid, actuated by a small "black box" computer. Hopefully this is not your case, as that computer is expensive!


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## Fedup (Feb 25, 2014)

Safety switches are not involved. The problem in this case is this. When the key switch is turned to the run position, the gauges, warning lights, and some other accessory circuits are powered on. One of those circuits is the signal to turn on the fuel injection pump. In most cases, these circuits are turned off when the starter is engaged. If this happens, the engine can't start unless a "jumper" circuit is added in. The 10 and 30 series tractors Ford built, including the S series, have a more complex electrical system than earlier models. The 6600 for example, has no electric fuel shut off, and far fewer relays, fuses and circuits. 
I have seen your problem before. It can be time consuming to track down. A few tricks I have used in the past - 1. add in a push button to supply 12v to the pump solenoid in place of your jumper. When you close the push button switch and crank the engine, it does basically what you're doing now. 2. Replace the key switch with one designed for gas tractors, which have an ignition circuit that remains "hot" in the start position. Problem with this, it usually has no provision for the thermostart, so you need to add in the same push button to operate that. 3. Add in another relay to supply temporary battery voltage to the pump. Utilize the start signal to activate the relay. When the starter is disengaged, the ignition circuit in the key switch takes over and supplies the pump coil. I have used all three methods over the years, depending on conditions, what's available, and what the end user is happy with.


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## carfarm (Feb 19, 2016)

*trick starting*

Thanks for the responses. It used to start fine without the jumper. I wonder if it could be in the key switch? I'm not opposed to adding a push button though. That would be an easy fix. I notice that when the jumper is installed, the electric fuel pump kicks on. Is it designed to run only momentarily until the engine starts or continuously?


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## Fedup (Feb 25, 2014)

Electric pumps should run continuously, and should be running whenever the key is in the on position. I wonder how it's being supplied after the engine starts and your jumper wire is removed? As I previously stated, Ford's engineers started getting wild with electrical circuits with the 10 series. You may need a wiring diagram that's specific to your tractor by model year and transmission option in order to track this down. You might be better served by simply adding in the necessary circuits needed and calling it good. Your tractor, your choice.


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