Starting Problem, Neutral Safety Switch or Starter Relay

[JByers]

I have a 2001 Sundancer with inboards, low hours and I'm having a problem starting the port engine, it won't turn over. So far I've always been able to start it but it's getting worse. I've moved the shifter back and forth and it didn't seem to help it. Does anyone know where the neutral safety switch and the starter relay is located? What's the best guess as to what it would be. Thanks John

 

[kaz911]

Starter relay is on the top of the engine (3 relays in a row - slightly to the left of the round harness "exit")

and I think if you look a little further to the left - you have the cables for the gears/gas - I guess the neutral safety switch would be attached there somewhere. (Above is based on 5.0MPI but I think they are very similar in build)

 

[Bt Doctur]

Velvet drives have it mounted on the transmission

 

[Amberjack01]

Similar problem with my 2001 290 AJ - twin 5.0 EFI B3s: problem getting progressively worse with port engine. Starter switch will not crank engine - holding the starter switch down and moving the shifter lever up/down through the neutral range - you can hear the switch clicking at the helm, and you can hear the relay working at the engine but the starter will not engage. Keep at it and eventually (within 20-30 seconds) it will suddenly start to crank and start up just fine. I know its not the switch at the helm because I have swapped the wires port/starboard and the problem follows the port engine. Defective relay? Any thoughts would be appreciated. BTW: my next move will be to swap the relays between the engines - that in itself may provide my answer!

 

[kaz911]

All I can say is - the most important tool to have on the boat is a multimeter Any $10 multimeter will do. Measure battery voltage while starting - then you can see if starter is really engaging. When engaging the starter the battery should drop to about 9-10.5 volt while the starter is trying to turn. (+/- dependent on battery size)

Battery fully charged is 12.6 volt. Normal "volt" rage is between 12.4-12.6 without load. Anything less the batteries might not be in the best condition.

If battery voltage goes down while starter is engaged the relay is working - but starter is not to happy. Check starter connection and look for corrosion. Just a slight bit of corrosion can partially short the starter to ground. I had to clean my starter-motor contacts every 1-2 years on my 210SEL due to corrosion.

If you want to splash out on good tools - get a DC Clamp Amp meter - then you can measure how many Amps the starter is burning. Put the clamp around the big fat Positive/Red cable and see Amp usage. A Clamp meter can ONLY be used on 1 cable. If positive and negative are in a bundle - you can't use the clamp meter before you separate them. If you have shore power get a A/C D/C clamp meter. If you measure Amps while starting - the amps until start should start VERY high - then quickly as engine starts to spin - lower to "high" amps - and when start is disengaged - go to almost 0.

Voltage and Amp's are very useful to know - and will cut debug time....