MX-5 Alarm and Starting Issues?

[puffernutter]

I have a 1995 Mazda MX5 with a Thatcham alarm fitted. About 6 months ago it refused to start. Using "start you bastard" proved that it was a fuelling issue.

I've put fresh fuel in and have a diagnostics doofah on the diagnostic port and I don't think that teh fuel pump is being powered.

So, I have the dash in pieces and I reckon it's one of two things - the alarm is not working and disabling the pump relay or the pump relay is knackered.

The alarm LED does a selection of things, rapid flash, steady flash, no LED etc., But I don't know what is should be doing.

So after that ramble - does anybody have a 1995 MX5 with a Thatcham alarm and what does the LED do, before inserting the ignition key and after inserting the ignition key?

Cheers

Peter

 

[Robotstar5]

I've not heard of an alarm/immobiliser actually made by Thatcham, they are normally other makes such as Scorpion, Cobra etc. which are "Thatcham approved".
Have look for a makers name on the "black box", it may give a model etc. to research.

 

[MoreWellie]

oem fitted "thatcham" alarm
@puffernutter you were lucky (unlucky?) the cat 2 alarm was only fitted on the mx5 May 94 – Sep 95

 

[gaz_moose]

if its an aftermarket alarm then the ignition wires under the dash cowling will be hacked about. just undo what has obviously been done to remove the alarm.

 

[MoreWellie]

does any of this help http://www.mx5nutz.com/forum/index.php?showtopic=134715

 

[puffernutter]

I've not heard of an alarm/immobiliser actually made by Thatcham, they are normally other makes such as Scorpion, Cobra etc. which are "Thatcham approved".
Have look for a makers name on the "black box", it may give a model etc. to research.

Sorry, type in haste, repent in leisure. Thatcham approved alarm! It is a "Toad".

There are lots of wires under the dash. What I'd like to do is prove/disprove the alarm being the issue. if I can keep it (as this is a rag top) then I'd like to, so ripping it out is a last resort. As it seems to do "stuff" when the ignition is turned on and the fob is close my guess is that it probably works, but I suspect there is a relay inside that cust teh power, so if that isn't working....

does any of this help http://www.mx5nutz.com/forum/index.php?showtopic=134715

I've actually bought an "aftermarket" diagnostic code reader that plus in the port and translates all the flashes into an LCD display and English! Much easier! That allows me to run the pump for 2s, but when triggered, the pump doesn't run.

I think I need to get into the relays (under the passenger seat I think!)

Cheers

Peter

 

[MoreWellie]

try running a 12v fused link from the battery to the fuel pump. The alarm will cut the feed to the fuel pump (and possibly other bits) so this will help you decide if it is the alarm or the fuel pump

connections to be found here http://hrc-performance.co.uk/mx5-fuel-pump-fitting-guide/

 

[p0689109]

try running a 12v fused link from the battery to the fuel pump. The alarm will cut the feed to the fuel pump (and possibly other bits) so this will help you decide if it is the alarm or the fuel pump

connections to be found here http://hrc-performance.co.uk/mx5-fuel-pump-fitting-guide/

Damn he beat me to it.!!

 

[MoreWellie]

Damn he beat me to it.!!

only by 3.5 hours so it was quite close really

 

[Ruffian]

Just find the fuel pump relay and pop the top off it and give it a little squeeze to make the contacts. No need for other wiring as will be fused through the harness

If the pump kicks in then you know its good.
And if you have crank and spark already then should start.

 

[MoreWellie]

pop the top off it and give it a little squeeze

probably not as the toad alarm system will be cut in to either the feed to the relay or the feed from the relay to the fuel pump

 

[Ruffian]

The imobizer would probably cut the signal wire as can control 5amps easier than a 20/30amp current.

 

[puffernutter]

It was the bl@@dy fuel pump! Having taken everything else to bits, that's all that was left.

A replacement and she started straight away!

Cheers

Peter

 

[MoreWellie]

guessing now isn't a good time to say didn't you read my post #7

 

[dobbslc]

I had similar thing once. The missus Peugeot headlights stopped working so I tore into the wiring, indicator stalk, relays etc and found nothing wrong. Turned out both bulbs had blown and she only noticed when the second one went!