Citroen C5 Mk1 (2004) Towbar Electrics

[myglaren]

You can in theory add them as attachments but there is a limit and many posters have discovered that the limit is reached rather quickly.
I find it simpler and more convenient to use an independent hosting site.

[frenchcarnut]

You can in theory add them as attachments but there is a limit and many posters have discovered that the limit is reached rather quickly.
I find it simpler and more convenient to use an independent hosting site.

Thanks, will do

[frenchcarnut]

Okay, so this is what I did:

[TrojanL200]

I have just got a towbar for my 2003 C5 Saloon. All the fitting instructions I have read say M10 40 bolts to fasten flanges to chassis.
OK down to screwfix M10 40 bolts and washers purchased. OMG come to fit them. No chance no bite and the bolts seem to have bigger thread dimension than the pre fitted holes in chassis. Am I missing something obvious here. M8's just go in and out M10's no bite and won't go in. Stressed now. Any help on this matter would be much appreciated
Kind regards
Chris

PS if I am posting in wrong place please except my apologies

[frenchcarnut]

I think mine were difficult from memory. Any rust in the way that needs cleaning nut/chassis side?

[TrojanL200]

I think mine were difficult from memory. Any rust in the way that needs cleaning nut/chassis side?

Cleaned the rust away but still no bite with M10 40's wondering if they should have tapered ends to allow initial burrow but that still shouldn't stop standard M10 40's. Will try WD 40 blast and fine wire brush before I try M10 40's again.

Thanks for reply mate

[lexi]

You may have to get a threaded tap and run it through the capture nuts. Make sure you have the pitch right for the capture nuts and the bolts or set screws you are fitting. Ie M10x1.5 or whatever it is. Support the car with blocks or similar at the sill jacking points before putting head under there. You probably know this but it must be repeated.

[TrojanL200]

I know this may be out of context because this post is about an older Citroen C5 2003. I have fitted a towbar but need to find right way to wire the single Electrics. I am used to splicing into wiring on other cars, but reading into some of the posts am I right thinking that there is an issue doing it the easy way I.e. relay needed.any help on this matter would be very much appreciated. And if I do need a dedicated loom wiring kit anyone know of one I don't have to buy from Citroen 1 mortgage in my life is enough lol
Thanks in advance all

[frenchcarnut]

I should have the original images of what I did somewhere. I'll email them over if I have. Give me about an hour and I'll have a look. I presume the bolts went in okay in the end?

[TrojanL200]

I should have the original images of what I did somewhere. I'll email them over if I have. Give me about an hour and I'll have a look. I presume the bolts went in okay in the end?

After some persuasion I.e. 1mm in 1mm out 2mm in 2mm out squirt of WD40 and carry on lol. Plus discovered flange side had been twisted when scrapyard men removed it but again a little brute force and pursuation sorted it
Will await images french
Cheers

[BX]

On the mk1 C5 you can just splice in the wiring in the old fashioned way. There is no bulb failure warning system to upset and the switching is done by fairly robust relays that in my opinion anyway are well up to carrying the extra load.
However I would always recommend you use a bypass relay box. Many of these have terms such as can bus, multiplex, smart etc used in their description but by and large are just dumb relays. These are available in varying levels of sophistication but as your car uses normal filament incandescent bulbs the most basic one available will do. I see two advantages in using one of these.
1. A fault in the trailer wiring will not affect the lighting of the car. For example a short in the indicator circuit of the trailer may blow the fuse in the car leaving you without indicators. Using one of these boxes will result in the fuse feeding the box blowing leaving the circuit on the car working.
2. Most give an audible signal when the trailer indicator is flashing.
I also recommend avoiding the vehicle emanufacturers kit like the plague. Many of these plug into the vehicle loom connecting to +ve, -ve and the can bus. I have previous bad experience with these on a non French marque. Over time dampness caused these units to fail. They sent rubbish into the can bus thus preventing the body computer from going to sleep. Almost every morning the battery was flat. Sometimes the lights wouldn't switch off and sometimes the engine wouldn't stop when the ignition was turned off. The solution was to remove the towbar wiring and replace it with a simple bypass box wired to the various circuits. This fault affected a substantial number of vehicles.
One last thing. Do not use scotchlock connectors.

[TrojanL200]

On the mk1 C5 you can just splice in the wiring in the old fashioned way. There is no bulb failure warning system to upset and the switching is done by fairly robust relays that in my opinion anyway are well up to carrying the extra load.
However I would always recommend you use a bypass relay box. Many of these have terms such as can bus, multiplex, smart etc used in their description but by and large are just dumb relays. These are available in varying levels of sophistication but as your car uses normal filament incandescent bulbs the most basic one available will do. I see two advantages in using one of these.
1. A fault in the trailer wiring will not affect the lighting of the car. For example a short in the indicator circuit of the trailer may blow the fuse in the car leaving you without indicators. Using one of these boxes will result in the fuse feeding the box blowing leaving the circuit on the car working.
2. Most give an audible signal when the trailer indicator is flashing.
I also recommend avoiding the vehicle emanufacturers kit like the plague. Many of these plug into the vehicle loom connecting to +ve, -ve and the can bus. I have previous bad experience with these on a non French marque. Over time dampness caused these units to fail. They sent rubbish into the can bus thus preventing the body computer from going to sleep. Almost every morning the battery was flat. Sometimes the lights wouldn't switch off and sometimes the engine wouldn't stop when the ignition was turned off. The solution was to remove the towbar wiring and replace it with a simple bypass box wired to the various circuits. This fault affected a substantial number of vehicles.
One last thing. Do not use scotchlock connectors.

Cheers BX;
I agree totally on the scotch lock comment. I prefer to solder due to proper connection.
Thanks for your input.....

[frenchcarnut]

I should have the original images of what I did somewhere. I'll email them over if I have. Give me about an hour and I'll have a look. I presume the bolts went in okay in the end?

After some persuasion I.e. 1mm in 1mm out 2mm in 2mm out squirt of WD40 and carry on lol. Plus discovered flange side had been twisted when scrapyard men removed it but again a little brute force and pursuation sorted it
Will await images french
Cheers

Hi TrojanL200,

Finally found original and annotated images with text comments on some. If you DM/PM a suitable email address, I'll send them over to you ASAP. I can't upload them here AFAIK and I have limited personal server space elsewhere. So I'll leave the decision up to you

Agree with BX regarding the methodology. That was more or less was my approach

[TrojanL200]

I should have the original images of what I did somewhere. I'll email them over if I have. Give me about an hour and I'll have a look. I presume the bolts went in okay in the end?

After some persuasion I.e. 1mm in 1mm out 2mm in 2mm out squirt of WD40 and carry on lol. Plus discovered flange side had been twisted when scrapyard men removed it but again a little brute force and pursuation sorted it
Will await images french
Cheers

Hi TrojanL200,

Finally found original and annotated images with text comments on some. If you DM/PM a suitable email address, I'll send them over to you ASAP. I can't upload them here AFAIK and I have limited personal server space elsewhere. So I'll leave the decision up to you

Agree with BX regarding the methodology. That was more or less was my approach

Got the images mate going to print them out to follow
The idea of the blocks to enable ease of disassembly good thinking
Cheers again mate. Hopefully when you get back next week I can give the thumbs up on mine

[TrojanL200]

Well just thought I would give an update. Towbar and Electrics now fully functional.
Thanks go to Frenchcarnut and BX for their valuable advise. And of course to the forum as a whole for being here.
2 more niggles to sort
A, the airbag fault warning on dash digital readout (all airbags fully functional)
B, EML antipollution warning ( I am beginning to beleive the previous owner was a very careful low milage Driver, and this has caused carbon build up to create the problem.)
I have bought some fuel additive from powerenhancer and the light only appears every now and then. I am thinking of stripping down the turbo and giving it a good clean out. Anyone's words of wisdom on these two matters will be most helpful.
Kind Regards to all.
Chris