Help guys no back lights

[frank20bcosmo]

Hi Cosmo Guys,,

I need your help, just had the interior swap done to turn my Type S in to a Type SX,, pictures and details to follow on another thread soon.

Heres my problem since the install I have no back lights working,, licence plate lights come on fronts are fine just the rears that have no current getting to them,, curent at fuse is fine,
Question 1 Has anybody got a wiring diagram for the Cosmo ?
Question 2 Is there a realy for the rear lights and if so can somebody tell where it is located and which one it is(thought)

I can still use car as brake lights fine but can't use it at night at the moment so need to get it sorted asap so your urgent help would be very much appreciated:'(

Thanks
Frank

 

[Galliano]

When you say you did an interior swap... do you just mean seats or do you mean seats, carpet, dash, doorcards and the likes?

When doing the swap, did you disturb any wires that run along the underside of the interior? You may have just popped out a splitting plug somewhere along the way.

Might sound like common sense, but sometimes we don't think of this.

 

[frank20bcosmo]

Hi Gilliano,

that thought crossed my mind ,,as yes apart from carpets and headliner the lot has been out,, but what threw me was that the Licence plate lights are working and I would of thought they would be on the same circuit.???

But maybe not !!,, thats what threw me to a relay for the rear lights,, just thought if I could see how the circuit is made up it would save ripping it out again.

that will be the last resort ,,,, i hope

 

[Berty]

Hi Gilliano,

that thought crossed my mind ,,as yes apart from carpets and headliner the lot has been out,, but what threw me was that the Licence plate lights are working and I would of thought they would be on the same circuit.???

But maybe not !!,, thats what threw me to a relay for the rear lights,, just thought if I could see how the circuit is made up it would save ripping it out again.

that will be the last resort ,,,, i hope

Try grounding the lights off to the rear of the chassis and bypass the main ground in the loom. At least this way you will know if current is getting to the lights.

 

[frank20bcosmo]

Thanks Berty,

I will give it a try and let you know

do you know if there is a relay for the rear lighjts ??

 

[frank20bcosmo]

(dance) RESULT !!!!!!!!!!!!!!!!!

Managed to sort out the lights so it can go in for it's yearly test and back on the road I was getting withdrawl symptons as been unable to use the car.

After much swearing and circuit checking it was a little device under the dash called a Stop and Tail Lamp Checker which tests the lighting circuit and if a bulb is out sends the signal to the dashboard warning you that you have a light out, after swapping units over from my 13B Cosmo hey presto lights working, my much stressed out mechanic is relieved as it would of been a dshboard out AGAIN if it wasn't this.

My next challenge is to find another unit to put back in the 13B so I live in hope that this is a unit that is universal to other Mazda cars like an rx7.

Anybody out there Know?
I will see what my local Mazda dealer says on Monday and finges crossed I can get one

Test day on Monday so fingers crossed Cosmo will be back on the road and I can get her booked in for the tune up

 

[Antoine]

Frank! I was just at my local Mazda Dealer picking up the Cosmo and I was able to score a couple diagrams of the wiring setup including the location for the rear brake lamp/light relay...I'll scan and post them here soon!

 

[Antoine]

Here are a couple scans of the relay schematics...

 

[frank20bcosmo]

Thanks Antoine

That is a handy bit of information, I am not sure if you read my other post but the culprit is a little black unit under the steering column that is called a
Stop and Tailight Checker
I swapped the unit from my other Cosmo and hey presto back lights working again.

I have an update on my Cosmo as I have had the boost controller fitted so I will post that soon

Regards

 

[frank20bcosmo]

Antoine, If I supply you with pictures of the little black box which is called stop and tail light checker would you be able to find out from your local Mazda Dealer friend what the part number is so I can order one from my local Mazda dealer over here in the UK?
Any help would be much appreciated as I am struggling to find one even second hand
Thanks

 

[Rotorzilla]

frank20bcosmo which box under the dash is it? Do you have picture of your box? When I converted my Cosmo 13B AT to 20B 5 speed. to get back up lights all I had to do was this

if you need the wiring manuals I have them here
http://rotorzilla.com/files/

 

[frank20bcosmo]

Hi Rotorzilla, the black box is under the dashboard, I think it checks the light circuit to see if any lamps (bulbs) are not working, however mine is faulty and it does not allow the lights at the rear to work and it is illuminated on the dashboard to show you there is a problem wih a light, I was baffled but I swapped it over from my other Cosmo an it worked fine with no issues, I will get some pictures of the offending unit and post them up n this thread.
Thanks for our help so far

 

[mazda speeder]

from what rotorzilla posted looks like you may be able to just hard wire (bodge) the plug connector?

 

[ADHD20B]

hey guys bit off topic need help with a compression test

hey guys, just need a bit of help and knowing why my compression tester is not reading anything... i mean nothing on all rotors, surely they cant all have no compression?
little help ?
cheers

 

[cosmojc]

Frank - There is a full ENGISH version of the wiring diagram in Aus. Dave has it and with some luck, may be open to sharing now that he is non-Cosmo!

Kramre

 

[frank20bcosmo]

Frank - There is a full ENGISH version of the wiring diagram in Aus. Dave has it and with some luck, may be open to sharing now that he is non-Cosmo!

Kramre

Hi Kramer,

I managed to find out what the problem is, it is a stop tail light checker, loks like a bigger than normal relay that checks the circuit and tells you if a bulb is out
in my case it wont light any,, I used another one from another cosmo I have and it works perfectly.
All I need now is another one, so starts the problem, I cant order one from Mazda as I do not have a part number and struggling to get a 2nd hand one, Rotorzilla is on the look out for one for me and Antoine is trying to get me a part number in case I have to buy a new one

Thanks

 

[cosmojc]

Post a picture of the part Frank - thats the sort of thing that gets thrown away all the time. There are probably some downunder. Last week I bought 3 sets of turbos a starter motor, two ignition barrels, a rats nest n some other bits n pieces that would have just gone to the dump!

KRAMER

 

[frank20bcosmo]

Post a picture of the part Frank - thats the sort of thing that gets thrown away all the time. There are probably some downunder. Last week I bought 3 sets of turbos a starter motor, two ignition barrels, a rats nest n some other bits n pieces that would have just gone to the dump!

KRAMER

I took your advice and have posted a thread with an image, see Cosmo Part Wanted
fingers crossed somebody will come up with it for me

Frank