Rev counter not working then flat battery

[ukcerb]

During a short run last night (headlights on) I noticed rev counter not working and when I tried to re start car battery was flat. I changed the big fuse a couple of days ago to avoid any problems when away in the car soon. Everything was ok on test after fitting although rev counter did not respond immediately but started working when I accelerated. so I checked with a circuit tester across the fuse terminals and it was ok.
Does this sound like the big fuse is still the problem. I didnt test voltage coming out other side of the big fuse so could it just be a bad earth? I am sure the battery is ok and it is on charge today to try later.
Any ideas? Regards Tim

[Phil_Edge]

Big fuse...

I had this recently.

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Even I managed to fix it

You'll be fine, and surprised at the results post-fix.

Edited by Phil_Edge on Friday 3rd April 08:26

[Phil_Edge]

p.s. Still have the pics if required, as they have timed out of the free hosting sites by the looks of the original thread. Don'tknow if you'd need them - they were only useful to numpties like me

[itiejim]

Yep, big fuse. I have also been through this trial recently. I had continuity showing across the fuse holder but it was obviously breaking down under load and wasn't enough to allow the fuel pump to prime.

The terminals and the fuse have to be really clean and tightened up properly.

[Phil_Edge]

Swap for the 125A or remove completely... seems to be the best advice around

[ukcerb]

Ok Thanks Phil and James. I will try giving everything a good clean and putting back together. I only changed from the original 100 amp to stop any problems when away. `if its not broken don`t fix it` comes to mind !

[Phil_Edge]

I'm not so sure on this... if you're going to the trouble of getting in there (assuming it's behind the block still) then I'd swap it for a shiny new 125A and new nuts. Fuses are £2. I bought a new holder and used the nuts of that as they were better (and clean of course) quality than the ones on her at the time...

[ukcerb]

Thanks Phil, Still got problems though. I took the fuse out and cleaned everything again then thought I`d check alternator output while fuse out. Seems the alternator has given up. Any ideas on replacement or can you change diode in situ. Seems awkward to get out to remove, even though I`ve already removed the fuel rail. Help! Regards Tim

[Phil_Edge]

Dammit - thats a worsst case scenario I guess...

Nothing much I can offer on that though, willing amateur, but thats it, sorry.

[ukcerb]

Ok thanks Phil. Found an alternator on e bay alot cheaper than `other` tvr prices and the postage was included! If all goes to plan i`ll be at the ace for ph meet on Easter monday.

[The_Edge]

Good luck with the 'transplant'

Mine's just gone to Austec for an MoT and then the final part of this round of tuning - the last remap now... so wont have here for the meet, then away for a couple of weekends, so following that, will be looking to get involved

p.s. Note the name change. Long story.

[ukcerb]

Good luck with all that then. Just got back from hols and my alternator hasn`t turned up so looks like I`ll be cerbless for a few more days. Is there someone else with your name? Regards Tim

[The_Edge]

No... changed on account of improved stealth for things like the "who fancies lunch" threads

[Barkychoc]

Never run an alternator with no load - it will be toast.

[ukcerb]

Ok thanks for that Chris. I will remember that when I fit the new one. Does that mean if the fuse was blown then no load would have killed the alternator anyway? How do I test the new one other than connecting everything and trying it? Regards Tim