Short, spark,sh*t and snakerred!

[Kurrawong_Kid]

Replacing exhaust manifold gaskets and elbow on a Volvo MD17 D I stupidly illuminated the scene with a 12v lamp from the boats battery supply. When attempting to remove a bolt above the starter I shorted out the starter solenoid and there was a bit of a display of sparks! Since the cabin lights, fridge etc. continued to work I was not too dismayed and just carried on with the job. Upon completion no engine electrics! I discovered a fuse was blown on the circuit from the starter switch to the starter solenoid and replaced that but still no engine electrics! I then tried a continuity test across 30 to 50 on the starter solenoid which showed no circuit. Am I right to assume this is the likely cause of the problem I.e. I’ve knackered the solenoid? Anywhere else I should obviously test apart from methodically going through all the wiring? Thanks in advance.

 

[sailorman]

U have an email

 

[VicS]

Replacing exhaust manifold gaskets and elbow on a Volvo MD17 D I stupidly illuminated the scene with a 12v lamp from the boats battery supply. When attempting to remove a bolt above the starter I shorted out the starter solenoid and there was a bit of a display of sparks! Since the cabin lights, fridge etc. continued to work I was not too dismayed and just carried on with the job. Upon completion no engine electrics! I discovered a fuse was blown on the circuit from the starter switch to the starter solenoid and replaced that but still no engine electrics! I then tried a continuity test across 30 to 50 on the starter solenoid which showed no circuit. Am I right to assume this is the likely cause of the problem I.e. I’ve knackered the solenoid? Anywhere else I should obviously test apart from methodically going through all the wiring? Thanks in advance.

Terminal 30 is the main battery positive connection. Terminal 50 is the connection to the solenoid. coil. There will not normally be continuity between these two. (Shorting them together should energise the solenoid and crank the engine)

Check the solenoid coil continuity between 50 and earth ( battery negative).

ITYWF that there is a multi-fuse holder in the feed from the main battery connection to the engine panel. ( A 6mm² red wire) I guess the fuse in use in this has blown, hence no power to the engine panel. You should be able to use one of the spare fuses in this fuse holder( unless they all been blown in previous mishaps) ( maybe this is the fuse you've already replaced ????)

 

[VicS]

Terminal 30 is the main battery positive connection. Terminal 50 is the connection to the solenoid. coil. There will not normally be continuity between these two. (Shorting them together should energise the solenoid and crank the engine)

Check the solenoid coil continuity between 50 and earth ( battery negative).

ITYWF that there is a multi-fuse holder in the feed from the main battery connection to the engine panel. ( A 6mm² red wire) I guess the fuse in use in this has blown, hence no power to the engine panel. You should be able to use one of the spare fuses in this fuse holder( unless they all been blown in previous mishaps) ( maybe this is the fuse you've already replaced ????)

Has a main "Mega fuse" been added in the feed from the isolator to the engine?
Do you have power at terminal 30 on the solenoid? .......... Check with your 12volt lamp rather than with a multimeter. If not look for a "Mega fuse"

 

[Kurrawong_Kid]

Has a main "Mega fuse" been added in the feed from the isolator to the engine?
Do you have power at terminal 30 on the solenoid? .......... Check with your 12volt lamp rather than with a multimeter. If not look for a "Mega fuse"

Thanks for the explanations. Will the check it all out next weekend. An additional fuse seems to be the most likely if the starter motor proves OK. Hope so!

 

[VicS]

Thanks for the explanations. Will the check it all out next weekend. An additional fuse seems to be the most likely if the starter motor proves OK. Hope so!

There is an apology of a wiring diagram in your owners manual but AFAICS it is the same as the wiring for the MD11C and MD17C

For a better wiring diagram down load the manual for these engines from VP's website. It may help if you have to do any extensive trouble shooting

 

[Kurrawong_Kid]

There is an apology of a wiring diagram in your owners manual but AFAICS it is the same as the wiring for the MD11C and MD17C

For a better wiring diagram down load the manual for these engines from VP's website. It may help if you have to do any extensive trouble shooting

Mystery thankfully solved and engine run! The Volvo fuse box you mentioned and to which I had swapped the wire was contaminated by rubber deposits from the “fan” belt dust. The tarnish was not easily visible without the aid of bright daylight. It was obviously an excellent insulator. Once the spade terminal was cleaned up the engine circuit was restored.
Thanks for pointing me in the right direction.