Help - Electrical Issues!

For all electrical questions; Alternators including fitment; Light connections/wiring; Instruments; Gauges; MFA; Heater blower (not coolant related) issues etc etc.

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Mophead
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Help - Electrical Issues!

Post by Mophead » Wed Oct 27, 2021 8:15 pm

I'm restoring a 1991 Scirocco Scala barn find. Initially the electrics seemed fine but everything underneath was totally seized. Eventually everything that was seized was unseized or replaced and I was able to drive it for a bit. At the end of August the feeder (intank) pump packed up so I got a replacement but before I could fit it the electrics died. Ignition turns on the lights/ indications (if they're on) and the main fuel pump but the starter will not engage. I get a battery error or the dashboard. I've checked the battery, the starter motor, the distributor and the wiring/ connections which as far as I can tell is properly connected and shows no sign of faults. I've replaced the ignition control unit, the fuse box, all the fuses, all the relays and it seemed to be the ignition switch which I replaced today but to no avail! And I can't take it to a garage as I've run out of money! Can anyone offer any help?



mark1gls
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Re: Help - Electrical Issues!

Post by mark1gls » Thu Oct 28, 2021 1:40 pm

So is the starter motor cranking over the engine at all or is it just clicking?


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Mophead
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Re: Help - Electrical Issues!

Post by Mophead » Thu Oct 28, 2021 10:36 pm

On tuning the ignition all of the electrics come on including the main fuel pump but the starter will not turn. I've put direct power to the starter and it cranks and also the +/- leads at the ignition switch connector and it also cranks. But no action from the ignition on it's own.



GT_II
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Re: Help - Electrical Issues!

Post by GT_II » Sat Oct 30, 2021 12:41 am

Mophead wrote:
Thu Oct 28, 2021 10:36 pm
I've put direct power to ... the +/- leads at the ignition switch connector and it also cranks. But no action from the ignition on it's own.
If I read this correctly (and I'm not certain that I do), this would at least confirm the earthing path is sound. So either a fault with the ignition switch or the +ve feed to the ignition switch. Do you have multimeter and wiring diagram to help trace the fault?


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Mophead
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Re: Help - Electrical Issues!

Post by Mophead » Sun Oct 31, 2021 2:09 pm

I have traced the fault using the manual and a multimeter. Last week it pointed to a faulty ignition switch. I removed and replaced this to find the new switch doesn't work. On putting the old switch back in without the steering lock the starter motor cranks but other things, which previously did work, like the fuel pump have now stopped working - meaning I'm no closer to starting the engine! My conclusion is that the movement of the key at the end of the steering lock is not properly interacting with the ignition switch and the ignition system wiring is bad and needs to be replaced which is sadly beyond my abilities so it will have to go to a garage. I suppose this was to be expected for a car stored in a damp shed for 10 years!



Village Idiots
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Re: Help - Electrical Issues!

Post by Village Idiots » Mon Nov 01, 2021 9:56 am

When you have the actual ignition switch dangling on its wires have you tried turning it with a screwdriver?
Odd functions coming and going suggest poor connections, have you tried using spray on electrical connection cleaner?



Mophead
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Re: Help - Electrical Issues!

Post by Mophead » Thu Nov 11, 2021 8:38 pm

So since last post I've cleaned all the electrical contacts and double checked all the connections which has made things a bit better. The ignition problem seems to be that the end of the ignition lock is not properly interacting with the ignition switch (the switch works). When I got the car I had to change all the locks but the new ignition lock worked fine for about 4 months then suddenly stopped. To complicate matter since I have got the ignition switch on it's own working the fuel pump relay has seemingly failed - meaning the car still won't start - but as new ones of these are pretty expensive I need to know why it's failed. Finally before all this happened the feeder (intank) fuel pump ceased functioning. I have bought a replacement but I also need to replace the wiring and I'm unsure of what sort of wire to use - being intank I don't want to get it wrong!