Intermittent complete ignition failure

[murf]

My series 1 Thema  turbo continues to baffle me with it's bizarre electrical behaviour so I would appreciate some feed back if anyone out there has come across a similar problem. I am currently on holiday abroad but the day that I left the UK the car on two occasions completely failed to respond to the ignition key [no lights or gauges came on and the starter would not turn the engine,not even a click]. There seemed to be no problem with the battery as the interior light and radio continued to work. I fiddled about with the ignition switch, turning the key round the other way etc in case the steering lock tumblers were sticking but this did'nt seem to make any difference and was on the point of giving up and calling out the RAC on both occasions when at my next attempt bingo!! We suddenly had normal working check lights ,ignition and a running engine. I headed for home and switched to my wife's car to get us to Gatwick so that we could make our flight but am going to need to get the old girl going next week as I'm back to work to pay for this weeks frivolity. Any suggestions would be most welcome.

Regards, Sunburned Murf.

[fay66]

Sounds like it might well be worth checking the engine earthing.

Brian
8227

[Scarpia]

It' s maybe unlikely but I presume you don't have a alarm/circuit breaker fitted wired off the ignition circuit.? If there are remnants of one fitted by a previous owner these can give all sorts of irritating problems.

I had exactly these symproms on a vehicle and after replacing the starter solenoid, then the starter motor, and being advised to chain the flywheel due to worn teeth, they finally tracked the fault (in the 3rd garage !) to the wiring for the alarm which fed off the ignition circuit. 

[murf]

Thank you gentlemen for the suggestions. I'm now back in the UK and have tomorrow before I return to work so I will check the earthing to the engine and also contact the original and only former owner of the car to find out if he ever fitted an alarm/removed one! Thanks again, regards murf.

[fay66]

It' s maybe unlikely but I presume you don't have a alarm/circuit breaker fitted wired off the ignition circuit.? If there are remnants of one fitted by a previous owner these can give all sorts of irritating problems.

I had exactly these symproms on a vehicle and after replacing the starter solenoid, then the starter motor, and being advised to chain the flywheel due to worn teeth, they finally tracked the fault (in the 3rd garage !) to the wiring for the alarm which fed off the ignition circuit. 

I would agree with William,
Lancai's do not like any added non -approved electrics, & alarms are a favourite source of problems, see Jack Romano's problems with his Dedra due to half an alarm system not being removed; in fact the handbook on Dedra makes a point of warning against altering the wiring, & if I remember correctly so does the Thema handbook.

Brian
8227

[murf]

I've dismantled the steering column binnacle and removed the rotating plastic switch which slots into the back of the steering lock casting but it's a sealed unit so although it seems to go round and click into different positions I have no way of testing it. The parts store man at my local Fiat dealership was friendly but unable to help saying he remembered this was an item that gave trouble way back in eighties. He also did a print-out for me which gives a part no 5888983. Does this ring any bells or could the switch be common to any other models in the Fiat range? Has anyone had a fault with this item and managed to get a replacement?

Regards, Murf.

[fay66]

TDC should be able to help out with one I would have thought, any particular reason to suspect the ignition switch is the culprit?
I've only had series 3 Thema's but I can't recall that it was a particular problem with Themas.

Brian
8227

[fay66]

I've dismantled the steering column binnacle and removed the rotating plastic switch which slots into the back of the steering lock casting but it's a sealed unit so although it seems to go round and click into different positions I have no way of testing it. The parts store man at my local Fiat dealership was friendly but unable to help saying he remembered this was an item that gave trouble way back in eighties. He also did a print-out for me which gives a part no 5888983. Does this ring any bells or could the switch be common to any other models in the Fiat range? Has anyone had a fault with this item and managed to get a replacement?

Regards, Murf.

Hi Pete,
Here are the other models it fits.
Brian
8227

[murf]

Many thanks Brian for that info. I have asked Desira my local Fiat dealership to order one in for comparison with the switch I removed from the steering lock so I,m hoping that this is the root of the problem. Kind regards, Pete.

[chugga boom]

i had a similar thing happen on my integrale, turned out to be the main earth lead from the battery had corroded inside the terminal that attatches to the engine/gearbox, i only found out when it burnt out the wiring to the ecu  if no joy with ignition switch i would definatly check main earths out, when i had a thema there was a main earth block behind the front grill that had corroded terribly, cant remember what fault i had  (it was about 8 yrs ago!) but i remember that being the culprit, good luck and hope you sort your car easily

[murf]

The saga continues. I eagerly fitted the new steering column switch on Saturday but to no avail so it looks as though the dodgy earthing is the most likely culprit.Thanks for telling me the locations of the earth leads, its horribly crowded and inaccessible under there but I will just have to bite the bullet and do a thorough inspection of all the suspects. Rgds, Murf