MOT failure - no dipped or main beam

[DaveVR 0]

Hi all.

 

I have an issue that I wonder if anybody can help with. The corrado went for MOT today and failed due to the fact I have no dipped or main beam. The car was locked away in my garage over winter so I took the battery off. I have noticed that in the past the headlight wiring has been messed with and in front of the battery where the clamp is located there are a couple of relays that are flapping around loose and the wiring to them is most definitely aftermarket so I’m convinced the fault lies there. I found one of the terminals had been knocked off by me wrestling the battery past it but they still don’t work with it plugged in. My question is this - I’m fairly new to ownership but have heard that the wiring looms are a problem area on these cars, to that end where can I find a decent wiring diagram to try to sort it? Also I heard of people selling modified looms to sort any common issues, where can I get my hands on one of those or are they obsolete now?

 

Thanks in advance.

[Cressa 44]

Try and get some pictures posted of the relays and the wiring. Hopefully someone may recognise what you have fitted.

Cressa

 

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[dr_mat 0]

Sounds like you already have an aftermarket wiring loom fitted.. one that's obviously failed.

 

 

A Corrado is for life, not just for the MOT.

[Cressa 44]

And hopefully could me as easy as replacing the relays.

You will need to start by checking you have voltage to the relays

 

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[DaveVR 0]

Thanks for the replies. It had occurred to me that it may have been an aftermarket loom albeit a poorly fitted one as the relay plates/relays are just shoved down there. I don’t know what a standard setup should look like so was hard for me to say. There is a fused feed directly from the battery along with an earth directly to the battery earth terminal with the wires encased in a plastic corrugated sheathing apart from where they go into the fuse connection and the relays. I will get some pics tomorrow and hopefully shed some light on it (no pun intended).

[Dox 23]

There is a fused feed directly from the battery along with an earth directly to the battery earth terminal with the wires encased in a plastic corrugated sheathing apart from where they go into the fuse connection and the relays. I will get some pics tomorrow and hopefully shed some light on it (no pun intended).

 

Have you checked that fuse from the battery?

[swiftkid 1]

As above, sounds very much like a headlight relay. 1 relay works the dipped and the other the main. Firstly, check the fuses, secondly check the relay. Likelihood is its a bog standard relay, unplug it from the housing and test it by putting a wire from battery earth to pin 85 and another wire from battery positive to 86, it should click.

Fingers crossed its one of those fixes!

 

You can buy expensive fancy wiring looms etc which do the job great but if its already been done, you might as well just make a nice job of it yourself with a marine fuse holder and waterproof relay.

[DaveVR 0]

Thanks for the above Dox and swiftkid. I only visually checked the fuses at the testing station as I didn’t have my meter handy and they looked ok but obviously could still be faulty. I’ll check the fuses and relays properly tonight/tomorrow and hopefully get some pics as the setup doesn’t look like any I’ve seen for sale or on here.

[Dox 23]

You can fire the relays with a 9V PP3 battery without any wires, the pitch of the connectors is ideal.

[DaveVR 0]

Ok so a bit of an update. Finally got chance to get in the garage to have a look at it tonight and found a couple of issues with it. Firstly, the fuses were ok but one of the relays is goosed due to some serious water damage. Secondly, the loom that is on it appears to be a bit of a DIY job and the wires out of the relay to the headlamps are crimped together but one of the crimps had broken meaning only one side is being fed. It looks like the whole thing needs a bit of an overhaul. I was tempted to just buy a full loom but on inspection the loom looks to be spliced in to the original headlight wiring.

 

Does anybody know whether the original wiring from the switch to the lights has a block connector that you simply plug the aftermarket loom into? The reason I ask is that I hear they are plug and play aside from the live and earth but both of my headlights appear to be hard wired with no block connector along the line. This does mean that the sidelights work even if the headlights/main beam circuit goes down but also means an aftermarket loom would be pretty pointless.

 

My next question is...where is best to buy the gear I need to repair the loom from? I know you can buy the stuff from Maplins etc but I want decent quality and wonder peoples opinions. As far as i'm aware the list of items I need are;

 

1. 2x 12v 40A 4 pin relays (where can I get decent water proof versions?)

2. 2x relay plates (may come with the water proof gear)

3. 2x waterproof fuse holders with 20A fuses

4. length of 20A cable

5. Various relay pins and crimp connectors

 

Lastly, where is best to mount the relays as part of the problem with mine is that it was just loose under the bonnet!

 

Sorry for all the questions as theyve probably been asked a million times before but any help would be appreciated.

[DaveVR 0]

A few pics...

[Jim Bowen 1]

I'd ditch all the aftermarket stuff and try to reconnect/fix the original wiring.

Should just be a case of joining the cut wires to the headlight connectors and plugging them into the headlights.

 

I've never really like the aftermarket looms as the relays aren't protected from the damp and you have to leave the headlight connection unplugged with a wire poked into it.

[dr_mat 0]

There are people making decent aftermarket looms with genuine connectors on so they are plug and play, but I agree in general. It's unfortunate the standard loom leaves the lights so under powered.

 

I bought a wiring loom kit about ten years ago and never fitted it due to concerns about reliability in the end. Think I'd be happy to sell it to you as it will have all the bits you need. I'll try to dig it out..!

 

Re buying bits. There was never anything wrong with Maplin stock quality, but obviously they are closing down so best hurry. Otherwise there's CPC and the other Farnell brands.

 

 

A Corrado is for life, not just for the MOT.

Edited March 24, 2018 by dr_mat

[fla 9]

You can make a new one - it's not difficult in fact you could just follow the same setup you have. Just make sure you seal everything nicely. I made my own loom and parts were only about £10.

[Jim Bowen 1]

I bought one with genuine connectors but you still have to leave the originals unplugged and poke one wire into it. Think i paid about £85 for it years ago and its just sat in a box. I had planned to cut it up and extend the wiring so relays can be inside the car and run a new wire so don't have to plug into the original connectors

[Wullie 1]

Maybe these will be of some help

 

[ATTACH=CONFIG]92593[/ATTACH][ATTACH=CONFIG]92596[/ATTACH]

[DaveVR 0]

Thanks for all of the help guys. I’ve now sorted it by putting two new water proof fuse links in and 2 new relays. It does need further work to neaten it up and I also want to water proof the relay pins somewhat but for now they all work and it’ll get through the MOT.