Assuming you mean a Volvo Td5 engine (same as Ford,Landrover) then this probably means some kind of either a) wiring fault b) ECU (Engine Control Unit) failure or c) a malfunction of a motor or electrical component of some kind. Alternatively, this could genuinely mean you have a engine problem, such as a faulty Mass Airflow Sensor or Lambda Probe in the exhaust. Neither of the above is serious, but I would recommend visiting your dealer because really this is something that can only be fixed by them (such as resetting your ECU).
check the dash board ground connection...it may be loose
this tells you is a simple wiring problem.most likely a loose wire from the third light to the other lights.(third lights provides the power to the other lights)
I would guess the headlight dimmer switch on the floor board is bad or has a loose wire. Possibly the head light switch is bad. The headlight switch has a separate circuit breaker for just the head lights.
If there is power lost, lights that dim and a battery light that comes on there is most likely a connection that is loose somewhere. It would be best to check the alternator or battery cables.
There has been a power failure to these lights. Check for loose wiring at the battery, a bad fuseable link, or blown fuse to start the troubleshooting process.
Blown fuse? Damaged buss board?
Take a light tester and check the pins at the truck side trailer plug. With the truck set for running lights check for power at the pins. If there is power then there is a loose or bad wire on the trailer side. If there is no power then there is a power problem on the truck side.
I would check for a loose alternator belt.
i would say loose power
Should be separate circuits for the dash lights and the radio. Look for loose/corroded connections on both power and ground wires. I would also check the dash light dimmer control switch. Verify you have power and ground at the radio. When the dash lights go out, verify power at the dash light fuse. It is going to take some detective work to locate the source of the problem.
Answer 1 - Instrument Lights Operate IntermittentlyWithout doing a "hands on troubleshooting" of your vehicle, no one here can be certain of the specific location and cause of your problem. However, based on your question, I suspect that the cause is a loose connection in the circuit providing power to the instrument lights, or on the instrument panel circuit board itself.It is possible also, that the instrument panel dimmer switch is wearing out.Answer 2 -The dash dimmer switch or the headlight switch is the most likely problem.
Someone knocked a wire loose.