Volvo 2003 panel problems

[Tintin]

I was hoping the removal of junk cable and fixing the multi connector would solve the problem but it hasn't, so some ideas of what to do would be appreciated pls.

The problem.....

Engine is a volvo 2003 of 1988 vintage with the standard panel.

With engine battery on and key turned pre-starting I only get the oil light lit, but no others.

Not sure if this is relevant but the backlight on the tacho works and the buzzer test doesn't.

On starting, the oil light goes out and the tacho stays dead and there appears to be no alternator output.

If I give it some revs the tacho comes alive and charging starts.

If I then back off the revs sometimes all stays good, sometimes tacho dies again.

I have squirted contact cleaner into the key switch and onto the multi connector at both ends.

Any ideas?

 

[AntarcticPilot]

I was hoping the removal of junk cable and fixing the multi connector would solve the problem but it hasn't, so some ideas of what to do would be appreciated pls.

The problem.....

Engine is a volvo 2003 of 1988 vintage with the standard panel.

With engine battery on and key turned pre-starting I only get the oil light lit, but no others.

Not sure if this is relevant but the backlight on the tacho works and the buzzer test doesn't.

On starting, the oil light goes out and the tacho stays dead and there appears to be no alternator output.

If I give it some revs the tacho comes alive and charging starts.

If I then back off the revs sometimes all stays good, sometimes tacho dies again.

I have squirted contact cleaner into the key switch and onto the multi connector at both ends.

Any ideas?

I don't think there is a "standard panel" as what you describe is different from mine, which is only a year younger. Mine is certainly what was fitted from new. The wiring diagrams in the manual show two options, neither of which have a key switch as standard; it would be simple enough to replace the "push for on" button with a key switch, but I don't think it's standard.

It sounds to me as if the alternator sensor wire has come off the board on the engine. I get similar symptoms if my alternator is not working (for some reason, the mounting bolt has sheared a couple of times; perhaps because a plain steel bolt was replaced with a stainless one), and on one occasion, the sensor wire came off the board on the engine, giving pretty much exactly the symptoms you describe.

My understanding is that there are two places where things can go wrong - the circuit board mounted next to the alternator on the engine, where the sensors etc. plug in, and the electronics on the panel itself. I've had a little trouble with the former - when working on the engine, it is very easy for connections to that board to come undone (they are only push-on spade tags). I've had to fix loose connections there several times - which is a bit of a game, as it isn't always clear which tag goes where, and of course it is in an awkward place to get to!

 

[ditchcrawler]

I have the same engine and my panel has key start.I had the same problem and it was the "exciter" wire to the alternator coming adrift from the panel.The alternator needs current to get it started so my electrician friend told me.

 

[Happydaze]

When the tacho falls back on my 1988 VP2003 it's nearly always a bad connection on the 4 way fuse box on top of the engine.

 

[RIBW]

I had the same problem and it was the "exciter" wire to the alternator coming adrift from the panel.The alternator needs current to get it started so my electrician friend told me.

I'd follow this path of investigation based on your symptoms. The alternator can be excited either through the 'alternator' (ALT) lamp or the temperature (TEMP) lamp on the instrument panel (I don't think it matters if it is key switched or has the push button for 'PANEL ON'). The fact you have an oil lamp indicates that the 12V supply is available in the panel. With neither TEMP or ALT, there could either be a dodgy path from the panel to 0V (via the stopped alternator) or both your lamps have blown.

Step 1 would be to test the lamps.

[The lack of buzzer is confusing]

Cheers
Bob