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post #4 of (permalink) Old 17th February 2007 Thread Starter
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Originally Posted by Horatio View Post
I don't know about other models, but some Lagunas certainly do have some multiplex wiring. Versions with memory mirrors and seats have these functions controlled via multiplex, though on other models they're conventionally wired.

The question on the towbar thread was whether or not the road lights are multiplexed. The indications I've seen so far would suggest that they're not. Specifically:
1) Renault's towbar wiring loom does not use bypass relays (though the lights might still be multiplexed, and maybe Renault believe the multiplex controllers can handle the extra load and potential faults.)
2) The point of multiplex wiring is to reduce the complexity of looms by sending just a power and a 'data' line to various computer modules around the car rather than powering each component individually. If this were the case on the Laguna, then I wouldn't expect to hear the relay for the rear fog lights activate behind the dash when I switch them on or off.
3) The various bits of wiring that I've seen suggest that looms with numerous wires are still present throughout the car. Though they could still be controlled by multiplex controllers, that would kind of defeat the whole object. I wouldn't expect to see much in the way of wiring on a multiplex system - just power lines and a common 'data' line to the various controllers, and then short runs of wiring from them to the controlled components.

I honestly don't think we're ever going to get a definitive answer on this one. I've asked the question in the past, and none of the resident Renault techs were ever prepared to bite. Somebody somewhere must know for sure, but they're keeping the information to themselves

Of course the real question on the towbar thread was whether or not bypass relays are necessary. Renault themselves clearly think they're not. If that's their view, then who am I to argue?
Thanks for that as i said before mines is fitted already with the relay so as you said its just a extra piece of mind .My friend fitted mines on both cars in the last two years and has been auto electrician for many many years when he fitted my other car the Merc C180 Classic it was the strait forward wiring. When i ordered the towbar for the Renault from A1 towbars they said it was required and if they were fitting the towbar they would not fit it without this box. So when i ordered the towbar i got the relay box as well and just as well because my friend would also not fit without the relay.Iam lead to believe that some insurance company's also will not pay out if there is fire damage when not fitted to 2000+cars and i believe it is also a legal requirement in some European country's.

So its done now and iam going to leave it at that but thanks again.
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2005 Mercedes Benz C200 Classic SE Kompresser & 1998 Fiat Cinquecento Fire Sporting,some may say i could do far better?,i say i could do far worse.

Last edited by Donald; 17th February 2007 at 06:28 PM.
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