Rollbar broke demister

Audio, Electronics and Lighting questions and answers

Moderators: timk, Stu, zombie, Andrew, -alex, miata

OurCognitiveSurplus
Racing Driver
Posts: 692
Joined: Sat May 09, 2009 2:40 pm
Vehicle: NB8A
Location: Canberra

Rollbar broke demister

Postby OurCognitiveSurplus » Mon Nov 14, 2011 9:01 am

Hi all

On the weekend I installed a MX5+ twin hoop roll bar into my NB8A. Wasn’t the easiest job in the world, but mission accomplished.

Before tightening all the bolts and re-installing the trim/carpet I did an electronics check and everything worked. After tightening all the bolts and re-installing the carpet, no more joy on the demister (doesn’t ‘click’ on, light doesn’t turn on).

I had the wire for the demister running under the leg of the roll bar, there seemed to be a fairly reasonable gap back there during the test fits.

I’m wondering if anyone has any tips on the first place to start trouble-shooting, or the easiest way to do a fix. I figure I’ve either crushed the wire under the rear leg of the roll bar (either shorting it or cutting the wire) or I’ve manage to pull something loose when putting the carpet back in. I had a quick snoop around but nothing seemed out of place.

Perhaps I should just cut out all the wiring from a point where it wasn’t interfered with by the bar (and should still work), up to the window, and solder in a new length of wire? Perhaps that will be easier than mucking around with a multi-meter for ages trying to find a break.
Any thoughts or tips or experiances appreciated - I'm a first timer at this sort of stuff!

Cheers
Greg
Image
NB8A - Twilight Blue

User avatar
Old Dude
Racing Driver
Posts: 1166
Joined: Tue Apr 07, 2009 8:06 pm
Vehicle: NB8B
Location: Gold Coast

Re: Rollbar broke demister

Postby Old Dude » Mon Nov 14, 2011 9:43 am

Put your multi meter on ohms, stick one side on the plug and Poke the other end into the plastic of the cable and see if you get a reading, if you don't the wires broken, and just replace the broken section or a better idea might be to use bullet connectors then it will be easier if you ever have to undo it for any reason. :)

Cheers
Dale 8)
"Everybody dies......, but not everybody lives" ;-)

MX 5 2001 Grace Green
NB8B

User avatar
taminga16
Speed Racer
Posts: 3617
Joined: Thu Aug 06, 2009 12:22 am
Vehicle: NC
Location: Central Victoria

Re: Rollbar broke demister

Postby taminga16 » Mon Nov 14, 2011 9:44 am

Check the cut out switch under the passenger side soft top stop, it is possible that it is stuck in the off position, and then check the cable for continuity under the mounting plates. An auto electrician could do this in about two minutes if you do not have a multi meter or test lamp.
Good luck.
Greg.
Sorry, I have re read your post and feel that you have cut the cable under the mounting plate which has caused a short that has in turn blown the fuse. G.
When you turn your car on, does it return the favour?

OurCognitiveSurplus
Racing Driver
Posts: 692
Joined: Sat May 09, 2009 2:40 pm
Vehicle: NB8A
Location: Canberra

Re: Rollbar broke demister

Postby OurCognitiveSurplus » Mon Nov 14, 2011 9:57 am

Ah - this is very helpful information. Thank you.

I knew that there was some system by which the system knew if the roof was up or down. Switch under the passanger side of the soft top - I'll have a look for that. I also hadn't thought of the fuse. I guess if I can find a blown fuse, I'll know the wires a cut.
Image
NB8A - Twilight Blue

User avatar
taminga16
Speed Racer
Posts: 3617
Joined: Thu Aug 06, 2009 12:22 am
Vehicle: NC
Location: Central Victoria

Re: Rollbar broke demister

Postby taminga16 » Thu Nov 17, 2011 9:55 am

Hi Greg,
Have you managed to sort the problem?
Greg.
When you turn your car on, does it return the favour?

OurCognitiveSurplus
Racing Driver
Posts: 692
Joined: Sat May 09, 2009 2:40 pm
Vehicle: NB8A
Location: Canberra

Re: Rollbar broke demister

Postby OurCognitiveSurplus » Fri Nov 18, 2011 10:50 am

taminga16 wrote:Hi Greg,
Have you managed to sort the problem?
Greg.


Hi Greg

I had a spare 5 minutes yesterday and had a look around. Turns out I'd left a pair of pliars sitting near the passenger side switch. Moved them - didn't seem to fix the problem. Had a jiggle with the wire - the wire looks like it's been subject to a number of very average quality repairs. It's ratty and has a lot of joints in (which is annoying because I paid an auto electrician good money to fix the demister after I got the car).

Now it works again - I think the jiggle was the ticket.

The good news is that that confirms that the problem is just that the wire is a bit crap - nothing more serious. If it gives me grief again I can just replace that section - it's easy to get to in any case.

Thanks for your advice - good to know where to look!

Cheers
Greg
Image
NB8A - Twilight Blue


Return to “MX5 Audio, Electronics & Lighting”

Who is online

Users browsing this forum: No registered users and 59 guests