Start Guard wiring problem

[Larry Thiel]

I have a 2008 Steiger craft with twin Susuki DF250s. I was having trouble with my new chart plotters resetting when I
cranked the motors over. I checked all batteries and connections all are good. The electronics are very sensitive to
voltage. I had this same problem on another boat but it was a twin inboard diesel. I installed a Newmar start guard to
solve this problem. So here is my problem. I installed the start guard on the outboard Steiger last weekend. It
requires you to run wires from each ignition switch that are hot only when cranking the engines over. This triggers a
relay in the start guard to supply battery power from the internal battery in the start guard to the electronics during
cranking the engines. From the back of the ignition switches the only wire that is hot during cranking is a brown wire
so I cut and installed a 3 way connector on the brown wire and ran a wire to the start guard for each ignition switch.
All worked fine untill I put the engine in gear and I get a check engine lite and alarm on both gauges and engines will
not go over 3,000 rpms. disconnect the wires from the start guard and all is back to normal. The brown wires are for
the NSS. I assume it is sending an incorrect voltage signal to the ecm caueing the problem. I do not have a wiring
diagram for this boat. But when I look at the wire on the starter soloniod it is pink then turns to red then white. as it
goes from the engine to the console i don't see a white wire under the dash. I think I have to splice these two wires to
seance voltage after the NSS switches so i don't get this code again but don't know the wire color under the dash to
splice into going to the starter soloniod after the NSS switches. Thank you in advance for your help.

[Moonlighter]

It is not uncommon to hear about chartplotter etc doing what you have described, and it's due to voltage dropping below the level that those units require to operate - and when starting the engines this can cause the voltage drop.

Having said that, modern MFD's now usually have suffucient voltage operating ranges for this not to be a problem unless there is actually some kind of issue with the wiring or battery.

The thing is, you should really find the root cause of the voltage drop to the MFD's, and rectify it.

When you say that you checked the wiring, what did you actually do? Load tested batteries? Checked all wiring with a multi-meter?

The best option is to run all electronics off a separate house battery and thus isolate them from spikes and voltage drops caused by engine starting. This approach also has the major advantage of avoiding the possibility of the house electronics, stereo, lights etc running down the start batteries when the engines aren't running. The modern approach is to have the house battery connected to the engines charging system via a VSR.

You haven't mnetioned how many batteries you have?

[artdf175]

I think your problem started by splicing the brown wire
The brown wire that comes out the back of the ignition switch is the main power lead feeding the ECM
You have interrupted the power and the ECM doesn't like what you have done
The brown goes to two places 1 to the ECM the other to the neutral switch and from there a Y/G wire to the starter relay - that is the one I think you should have spliced
Art

[redlowrey]

That's right art, that brown wire going to the ecm tells the ecm that the ignition switch is in the crank position with battery voltage when cranking, and it will put a ground on the starter motor relay and a ground on the injectors if the neutral switch contacts are closed from the neutral switch on the engine. I think his problem is a back feed from the device he hooked up and when he puts the shift in gear and the neutral switch contacts open, the ecu is still seeing battery voltage at the ecu instead of 2.5 volts and brings on the alarm and check engine light. This is what happens on a df,90 115 and 140, when you turn the key to the start position battery voltage will flow through a brown wire through the neutral switch in the console down the loom then splice off to the ecu via pin five and continue to the neutral switch on the engine. If the contacts are closed battery voltage will flow to the starter relay, and there will be 0 volts on pin 5 at the ecu. When the shifter is placed in gear the contacts open and the ecu will see 2.5 volts on pin five, I think the ecu is still seeing battery voltage on pin five instead of 2.5 volts. Two diodes will fix that problem and stop any back feed.

[wilbur1]

What size wire powers your Chart plotters? If you run 12ga. direct from the start bat. your problems will be over.

[artdf175]

Running a new wire to power the dash is not going to fix the problem of splicing into the wrong wire that powers the ECM
Yes the electronics are sensitive to voltage, but my experience has been they usually don't shut down unless the power is interrupted.

Your dash switches are most likely wired in series
You should find the power source on the first connection in that series and it should be a heavy red wire
Power branches to the other switches from that connection
Fix the splice first and then let us know the results
Art

[Larry Thiel]

Thank You all for your help and replys with this issue. I will check the wiring out this weekend. I also ordered a Factory service manual and had the wiring diagram blown up so I can read it.

[Larry Thiel]

Thank you all for taking the time to help me with my StartGaurd wiring problem. artdf175 i think you are correct that I have to splice into the YG wire. I looked at this over the weekend and also recieved my service manual. There is no YG wire under my dash area so it looks like I will have to run 2 wires thru the wire loom from my dash area back to each engine and splice into the YG wire at the starter relay and that should do the trick.

[artdf175]

the y/g wire would not be under the dash.. it should be coming off the back side of the neutral switch in the remote..

if you can see that wire, it maybe the one to attack..

or maybe the y/g wire comes out the back side of one of the wire bundles coming from the remote heading to the engine..

[redlowrey]

Thank you all for taking the time to help me with my StartGaurd wiring problem. artdf175 i think you are correct that I have to splice into the YG wire. I looked at this over the weekend and also recieved my service manual. There is no YG wire under my dash area so it looks like I will have to run 2 wires thru the wire loom from my dash area back to each engine and splice into the YG wire at the starter relay and that should do the trick.

'''''''''And then send the back feed through the yellow and green starter relay coil to ground in the ecu, you want to hope the voltage is not to high or it will energize the relay.