Cost to replace wiring harnesses on 1998 F1 355

Front? wiring harnesses?

If you know the part numbers, just Google them for retailers. The factory does seem to be still making them. Some are relatively cheap, some not so.

https://www.eurospares.co.uk/Ferrari/355/355_(5.2_Motronic)/PartDiagrams/140/Electrical_System

There is the main engine wiring harness (that goes from the Engine ECU in the cabin to most engine components). Engine out job. Part number depends on vehicle assembly number/country/etc. https://www.eurospares.co.uk/Ferrari/355/355_(5.2_Motronic)/PartDiagrams/007/Injection_Device_-_Ignition

There are two wiring harnesses which run down the sides of the engine compartment, but join up into one and go down the centre of the car to the relay panel, etc. An engine out would certainly make changing this easier. Depending on the country, they could cost (new) from $500 to several thousand dollars. USA Spider P/N 169101

There are shorter harnesses in the engine bay. e.g. one feeds the starter solenoid, alternator, ac compressor and various engine sensors.
There is the F1 harness.

It could be any one of these causing starter issues. More information required

 

I'm still not sure what they mean by two front wiring harnesses. Front to me = luggage compartment. Cabin = Cabin. Rear = engine bay.

(EDIT: original message edited for extra detail)

 

Here's a non-Spider cabin to engine bay harness just to show you how it splits into two

https://www.ebay.com/itm/253886586359?epid=6024018092&hash=item3b1cd1ddf7:g:ky8AAOSwOURbpMcY

Used Spider equivalents are available, but with used, there are too many unknowns.

 

Something is getting lost in translation. Can you convey your mechanic's assessment with more detail?

 

I don't like diagnosis via parts changing. The reason for changing out an entire harness (which is a big job) is because of substantial damage to the harness, such as because of fire or burned wires from a short or an aftermarket alarm installer who really hacked it up. An intermittent no-start condition is not a good reason to swap out harnesses. Your mechanic should be able to diagnose what's wrong and fix it. Again, unless something is being lost in translation and he has indeed found terminal damage in the harnesses you mention.

 

If it cranks but won't start it's either fuel or spark. Pretty easy to check each. I don't have experience with 5.2 cars but perhaps an immobilizer issue? As Targatime said, if they want to replace the harness have they found substantial damage?

I hand a related issue on my 2.7 car. Intermittently it would only run on one bank. Took a little time to find. Continuity checks, a little tugging on connectors. Turned out that a wire broke inside the insulation at the crimped on connector pin as pictured here, and the broken wire would make intermittent contact. Once found a simple fix. No need to replace a harness. But dealers today don't bother. No money in proper diagnosis.


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Taking him literally, there is no red wire going from the ECU to a relay. Perhaps he said relay panel? A red wire goes to fuse 30 on the relay panel in the passenger footwell. Unfortunately, he is the only person who has the hands on the car (we can only guess what he's seeing). If there are multiple mismatches in wiring, I can't say I blame him for wanting to restore the car to originality. As far as I know, the red wire must be working as the car wouldn't crank without it. The red wire supplies live battery power to the ECU. Without that, I don't think the ECU would tell the F1 TCU that the immobiliser had been disabled. The F1 TCU controls the starter relay and the starter wouldn't crank.

There have been a few of us in the same position. My car didn't even have the correct engine harness when I bought it and lots of wires had been "rearranged" to make the car function. Also, the CEL had been wired so that it would illuminate on startup, but wouldn't show there was a fault. In your case, the CEL bulb has probably been removed. Welcome to the shonky world of second hand cars.

There are lots of message threads on the forum relating to "cranks but doesn't start". Might be worth your time to take a look at those. Whilst a car really shouldn't have the parts cannon thrown at it, with intermittent problems, sometimes that's all you can do. In a big workshop, parts can be interchanged between cars, but it's still time con$uming.... Changing an entire harness, though, and not knowing if it will fix the problem, is on another level of desperation and cost.

Beautiful car, by the way. Definitely worth fixing