claggy001 Posted October 23, 2007 Report Share Posted October 23, 2007 (edited) Evening All! I'm sure I've seen this topic elsewhere but since the search engine won't cope with the word 'hot' I'll have to ask it again. After a short run today, just about 15-20 mins, i noticed the ignition switch was too hot to touch when I turned the engine off. Any suggestions as to why this should be? Also, over the last couple of days, when I've gone to start the car, sometimes when I turn the ignition switch to the start position, everything (fuel pump, starter motor, oil & ignition warning lights) cut out and the ammeter swings across to maximum discharge. Are the two problems related? I'm thinking dodgy contacts in the switch. I'm sure I'll be proved wrong! Thanks Edited October 23, 2007 by claggy001 Quote Link to post Share on other sites
Bob Stubbs Posted October 23, 2007 Report Share Posted October 23, 2007 Yes, the problems are probably connected. I had the same problem when I first got my 6 about 5 years ago. It hadn't been run significantly for years and parts of the electrics had just deteriorated. I changed the switch assembly pronto (and not that long after the alternator) and all has been well since. The last thing you want is a melted wiring loom or worse still an under dash fire on your hands. Quote Link to post Share on other sites
Guest Wyn Posted October 24, 2007 Report Share Posted October 24, 2007 Although not directly related to your query, I had the unpleasant experience of driving along smelling burning from under the dash, it is not nice I assure you. I have now fitted a battery cut out switch next to the steering column, it's the only place I found where it was not in the way and also easily accessible from where you sit. I did have one under the bonnet but by the time you unstrap, open the bonnet etc, god only knows what state things would be in. Regards, Wyn Quote Link to post Share on other sites
ianc Posted October 24, 2007 Report Share Posted October 24, 2007 If you have an alternator (rather than a dynamo) fitted, as will be the case on a TR5/6, and possibly on a TR4A, remember to stop the engine BEFORE isolating the battery, else you will likely cook the alternator. Why? Because the alternator needs the battery to be there to provide a reference voltage - if it is no longer in the circuit, the alternator just winds its voltage up and up and ... bang! The symptoms described definitely point to high resistance in the contacts inside the ignition switch. You may find that a good dosing with electrical contact cleaner (immersion is even better) whilst operating the switch back and forth, may resolve the problem. If not, new switch (or a good second-hand one. Ian Cornish Quote Link to post Share on other sites
badshead Posted October 24, 2007 Report Share Posted October 24, 2007 Mark Ignition switch diagnosis may well be your problem, but you could also try wiring the electric fuel pump (especially if it's a Bosch) direct to the battery and see if things cool down. I had a similar problem a few years back which was solved by taking the pump out of the ignition circuit. You can then power it via a ignition controlled relay. Quote Link to post Share on other sites
millsie Posted October 26, 2007 Report Share Posted October 26, 2007 (edited) Hi - I agree with Badshead, change the ignition switch and fit a relay to run your pump, the Bosch unit draws significantly more than the Lucas pump and either way a relay makes much more sense than running just through the switch itself. Last time I fitted the ignition switch (Rimmer) had to order 3 before I got a good one, may just be bad luck but worth being aware of. Cheers, Dave Edited October 26, 2007 by millsie Quote Link to post Share on other sites
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