Radio cuts out when start engine

Disco 1 200TDI 1993
Recently got the above which did not have a radio in it. Have fitted a Sony head unit via the wiring loom/connectors and the radio works when the ignition is on. As soon as I turn the engine on the radio cuts out. can anyone help with this
thanks

A lot of headunits cut out when cranking that's norm, if that's what you mean.
If not then you will have to look at the units connections and/or the the ignition switch to find a 'live' while the engine is running, it's a strange one.

thanks discool, it cuts out and stays off, so I do not think it is the head unit. another thing I noticed even before connecting the head unit is a loud cracking/clicking noise from the speakers when turning the ignition on/starting the engine. Would that be anything to do with the sub woofers in the rear speakers

glen40 said:

thanks discool, it cuts out and stays off, so I do not think it is the head unit. another thing I noticed even before connecting the head unit is a loud cracking/clicking noise from the speakers when turning the ignition on/starting the engine. Would that be anything to do with the sub woofers in the rear speakers

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Don't know but it shares the same 12v supply if any electrical problems with the amp it would blow the radio fuse in the dash fusebox.

Time to put a meter on the connections at the back of the ign. switch the wire to look for is red that's the switched supply and it changes to red/black at the head unit and purple/white is the permanant supply at the unit.

ignition switch faulty possibly or bad earth

Have messed about with the wires, all look ok, will have to get a meter to test them, any advice on what to go for?
On taking the Radio fuse out from B9 the loud clicking noise disappears, could this mean a bad / faulty connection somewhere?

Fusible links in main battery +ve cable.

nicedayforit said:

Fusible links in main battery +ve cable.

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Sorry dont understand!

LR in there wisdom decided not to use conventional fuses in the engine compartment of 200tdi's unlike later in the 300tdi's.
Instead they used fusible links which are in fact bits of fuse wire incorporated into the main +ve battery cable.
These things

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Unfortunately these fusible links tend to corrode badly causing dubious electrical problems on vehicles such as bad or non-existant connections, shorts etc.
If your's haven't been sorted in the past they will be due.

Start at the battery +ve terminal and work back along the battery cable towards the cab and you will find a lump in the cable. Unwind the wrapping and you will find the fusible links or what is left of them. Simply a case of sorting out what you find by either installing in-line fuses to replace the links or replacing the cabling and installing a separate fuse board like those in a 300tdi from a scrapyard.

Can't guarantee this is the cause of your problem but I reckon at least one of your fusible links is in very poor condition and is causing a high resistance in the cable feed to your radio such that when you start the car the voltage to the radio drops to such an extent as to cause it to cut off.

many thanks will take alook at these, seems drastic to get radio working but will check out to find cause

fanatic said:

ignition switch faulty possibly or bad earth

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Messed about a couple times with this but still no luck. How do I check for a bad earth, does that mean no earth or poor connection or intermitent earth. Do I need a meter to test and if so what kind of meter would people advise

Bad earth = poor connection

Just get a generic cheapo multimeter from maplins, all you want it for is finding a 12v feed and a good earth to wire your radio into.

Not sure if the 200tdi has a earth point on the inner wing just behind the battery but i had the same problems on mine so took the earth lead off the battery and re-soldered the joint just behind and it cured them.