Volvo 2002, alarm before the engine starts.

[Hachi]

Hi
I think I have a problem somewhere in the circuit of a Volvo Penta 2002. A week ago, when I switch on the starting panel the oil pressure alarm was triggered before the engine start.
Despite the noise, the engine started with no problem and the alarm instantly stopped at the same time
But when I stopped the engine, the alarm and the oil pressure light started again. This light (oil pressure) is the only one that works on the panel.
I also noticed that my rev counter is dead.
I tried to check the wires below the fuse box were I think is the problem, but my knowledge is very poor in electronic
Any help would be very appreciated
Thanks

 

[john_morris_uk]

I'm not sure you've got a problem with the alarm. My engine does exactly the same.

However when my tach stops reading it's usually an indication that the alternator isn't working. The other warning lights not working is also a concern. Bulbs? Sender units?

 

[PaulRainbow]

The oil light sounds to be working as it should to me, if the engine isn't running there is no oil pressure to put the light out. Same with the buzzer. The buzzer usually sounds before the engine starts, because of a lack of oil pressure and also a lack of charging.

The failure of the rev counter could be a wiring fault or as previously mentioned, the alternator. If the charging light isn't working, that might be a good place to start. Fixing that might help to tell you if your alternator is charging or not.

 

[RIBW]

Hi
I think I have a problem somewhere in the circuit of a Volvo Penta 2002. ..Any help would be very appreciated

It might help with diagnosis if you have a read of this:-
https://www.dropbox.com/s/s483ek6t42rqhmq/INSTRUMENT PANEL12V.doc?dl=0

and then list how your unit does not comply with the lamp on/off and sounder combinations.

Note that, with the engine stopped, the alarm should sound only if the sounder circuit has a path to 0V (usually the test switch being pressed)

Cheers
Bob

 

[{151760}]

You may well be right in looking below be the fuse box. I had random things happening with my panel last year. I called in a technician who diagnosed it as a bad earth. It was a corroded connection in a black wire protruding from the harness, just below the fuse block.

 

[Ferring]

I also have an intermittent rev counter on my 2002 but if you wiggle the ignition switch it clears. Obviously a problem with the ignition switch in the run position.

 

[Hachi]

Thanks for the help...

I do have a problem with the alternator (not charging or randomly charging) I still don't know if it is a wire, or something more important is broken.
Batteries are good, the voltmeter on the main panel shows 12.4V before the engine starts but it drops to 12.1 or less with the engine running (even in full throttle).

I think the box beneath the fuse has something to do with the issue, or is the problem itself. I tried to follow the wires after they leave the main cord but they are all green painted and is impossible to distinguish one from another.

I don't know how to isolate the problem

 

[RIBW]

I don't know how to isolate the problem

See #4 above
Bob

 

[Ferring]

That is very similar to my intermittent problem. Sometimes after starting the battery does not charge and the rev counter does not work if you leave it fr a short while the alarm sounds and all alarm lights flash. It can be fixed by moving the ignition key gently to the right (same direction to engage starter).
if you follow the correct 2002 cold start it does not happen very often.
Cold start : open +/- half throttle in neutral; turn on ignition; pull engine cut out up and release, then turn starter. Engine will fire up and run quite quickly, slow throttle down to idle.

 

[Hoolie]

Another possibility to look at that we encountered is a fractured -ve lead on the alternator. Charging and rev counter were very intermittent until they failed completely. Rather to my surprise the alternator was undamaged when I re-connected the lead.

 

[AntarcticPilot]

The lead from the alternator to the fuse box can easily come off - it's a spade tag on the fuse box. If that is off, you'll get exactly the symptoms you describe - it happened to me!

PS. Mine's a 2003, but I presume the electrics etc. are the same or very similar.