electrical problems post new dashboard

[timshap]

I have just taken out the old dashboards and had the standard metal boards bead blasted, flatted, brushed and clear gloss powder coated..the result I think is beeter than ally. Upgraded the yellow clock lamps for LEDs from aceparts. The result looks great and have built all up again to find that the (on mine) lower middle red led alt charge does not come on when the ignition is on. I have tested the wiring and have 11.4 volts when ignition is off and as soon as you switch on goes to zero.....I will get the led tested at maplins and try and get a replacement. Also checked the alternator output on full load...everything on and it giving out 11.4 volts. Does this seem too low I had hoped for more than 12 volts to keep battery topped.


Also when engine is running the fans do not come on when at 90 but come on when engine off. I also have a fan override switch which does nothing when engine running but when off switches the ignition on and fans come on....strange!!
I think the otter switch on the swirl pot is stuck as soon as i disconnect the fans stop etc..

So I reckon hopefully the led light need replacing and new otter..

Your comments would be welcome..thanks

[paulathome]

If you have fitted an LED lamp to the alternator charge indicator on the dash, then I would put a normal bulb back in. An LED only conducts in one direction so will probably upset the alternator
field windings, of which the alternator charge lamp supplies.
Easy fix.
Good luck and post us all a picture of the finished job.
As for the fans behaving strangely, Have a look for a dodgy earth wire as that seems to me would cause this type of fault.
Paul.

Edited by paulathome on Sunday 31st October 15:39

[timshap]

Will post the pics...

When i mean led its the little red lamp (there are 3 vertical between tacho and speedo in a 94 chim) which I thought was an LED. Its the same lamp which is not coming on.
I have only changed the lamps on the clocks for LED type which all seem fine

[spend]

You may have wired it the wrong way round, swap the wires around.

[Nosh]

timshap said:

Will post the pics...

Would love to see some pics....

....one of my jobs to do this winter....also got a 93 and looking at a 'different' way to go than SSteel or veneer....

Nosh

[ralphy12345]

timshap said:

Upgraded the yellow clock lamps for LEDs from aceparts.

Hi there,
could you tell me the correct ones to order from aceparts, please? (I'm a numpty when it comes to bulb selection!)

R

[timshap]

All but the clock are bax 7's...The clock has one smaller and think its a 5..Need to check the order when back in the office..

[fog66]

Just finished mine.

[timshap]

spoke to a helpful man at racing green today and have ordered new fan relay, ignition relay which he reckons is sticky due the fact that the ignition is on even when the key is out!!
New otter, temp sender and thermo on its way so hopefully back on the road for 1st Dec

Also reckons that because I have no light on the battery lamp the diodes in the alternator have gone..The alternator only giving 11.4 volts under load etc. Refurb of alt to do.

Will post photo when all back together

Cheers

[spend]

Did you rev the car well before testing the alternator output?

If the LED isn't lighting the alt may need to self excite which needs @2500rpm before the field coils are active.

Pull the ignition relay and check the ignition switch isn't supplying +12v when off across the smaller contacts at the fusebox. I'd always advise keeping a spare ignition relay anyway - it is a bit of a show stopper being unique and absolutely essential to run with.

[timshap]

Spend

This is a strange one and believe the ign relay is stuck etc..I will check the reve range for ther alternator and in the past the red light would come on and stay on with the engine on until I blipped the throttle at which point it would go out and I assume that at that point the battery was on charge etc..

I will check the alt output under load having revved up a bit. should i get at least 13 volts at that point though ?

I should be able to check the led / light is working by connecting to a 12 volt supply.

[spend]

Sounds like you have never had the field coils energized through the LED from what you say. Whether that was a fault in the alt light circuit or alt itself I don't know? Typically TVR install a LED with a resistor in parallel, ensuring the field coils get 12v to excite them if the LED fails (or loading?) so you should see charge almost immediately and it should be @14 volts if the alt is hunky dory. Alternatively if the sensitivity of the LED is too great it will look like its on if the battery at 14.4V compared to the rectified sense circuit at 12V provides enough forward voltage to illuminate the given LED.

Some of these TADTS's can get slowly translated into "can't be @rsed to fix it's" IMHO. Just because something seems to work when you've 'fixed it' might just be because you've not be checked it out properly I always like to wait at least a month before I'm sure a mod I've done works to my satisfaction, counting chickens always seems to bite you in the rear

[timshap]

Hoping to get car back with new roof soon and will post pics of dashboard which i am very pleased about.
As suggested earlier the alternator was at fault so replaced with a new one and the charge led light all working fine now.
I have really enjoyed doing this job and post new roof and wheels car should be returned to previous form

Tim