Getting electrical cable from the engine bay into the cabin of the car

[ozfrog]

Peugeot 307SW 2007

I need to get some electrical cable between the car/ cabin and into the engine bay. I’m trying to wire a light bar, and whilst it isn’t necessary now, I prefer to have a switch separately so that I can turn on the main beam lights without the light bar being turned. And for that, I need to install a switch for the lights

There has to be some way of getting the cable between the two areas, but what is it, and where is it, please?

[xantia_v6]

You should find some cut-off wire ends in the engine ECU/fuse box, and the other ends should be near the BSI inside the car. The exact purpose is unclear, but PSA seemed to fit these to everything.

[ozfrog]

You should find some cut-off wire ends in the engine ECU/fuse box, and the other ends should be near the BSI inside the car.

I must be blind. I can’t find any cut off wire ends, either under the bonnet, or presumably, under the dashboard near the glovebox.

But I did see a rubber grommet-looking-thing almost at the top of the firewall. I’ll need to go back under the dashboard, this time with some good lighting, and see if what I think was a grommet, is in fact a grommet.

I’m going to write down my thinking to get this done. If you have any better ideas for me, please tell me!

Then, if it is a grommet, I will try and make a pull through device using a wire coat hanger.

Firstly, make sure that I cover the ends of the coat hanger because I don’t want (or need!) to damage any existing wiring that might already be going through the same grommet.

Then I’ll aim to (gently) push one end of the hanger through the grommet, far enough to see it appear into the engine bay. But at the same time, needing to be sure that it doesn’t disappear from under the dashboard.

I think I can detach the switch from the wiring harness. So I’ll then attach the end of the harness to the coat hanger, and pull through the wiring for the switch. (I haven’t yet figured out how to attach the wire to the coat hanger to make sure that it stays attached when I am pulling it through the grommet. My first thought is to wrap the wiring and the hanger together with duct tape. I don’t know if it’s strong enough, but there’s only one way to find out, I suppose. My other concern is whether it’s going to make everything too thick. Again, only one way to find out.

The switch that’s included with the wiring harness is an attractive looking switch, but it isn’t a Peugeot style switch. Ideally, I’d like to place a Peugeot switch in one of the blank switch spaces on the dashboard, above the air vents in the centre of the dashboard. But I think that would mean taking apart the whole dashboard. And to place a switch in there? I don’t think that’s going to happen. Most likely, the switch will be somewhere around the manual headlight adjuster. A Dremmel-type of tool should make that happen easily.

The rest of the wiring is covered in the fitting instructions, which, for a one A5 page, are surprisingly good, I think.

As I said above, if you have any better ideas, please tell me, preferably before I get started, which will be Friday morning, Sydney time.

[mickthemaverick]

Sounds like a plan but if your object isn't a grommet you can drill your own hole through the bulkhead once you establish it is clear on both sides. One tip I can give you is attaching your wire to the draw rod, I always use the method shown in the picture. Be sure to have enough wraps, I usually go 75cm or so and ensure the tape sticks to the rod in between the wire loops, ie don't wind the wire tight and then try to fix it. This method gives good adherence and minimal thickness.

Connecting the wire to your draw rod

[ozfrog]

you can drill your own hole through the bulkhead once you establish it is clear on both sides.

I’m not sure how comfortable I am drilling through the bulkhead! And that’s without even considering the risk of not having clearance on both sides.

One tip I can give you is attaching your wire to the draw rod, I always use the method shown in the picture. Be sure to have enough wraps, I usually go 75cm or so and ensure the tape sticks to the rod in between the wire loops, ie don't wind the wire tight and then try to fix it. This method gives good adherence and minimal thickness.

I think I understand that. I hope it will make more sense when I’m in the situation and doing it rather than just reading it and trying to visualise it.

(Did I get your phone number when I was going to be picked up at Heathrow? (Until I made the mistake of arriving on the wrong day. Oops. If I did, I’ll just ring you with my questions when I’m stuck. You won’t mind if it’s 3 A.M., will you?)

[Trickiedickie]

So if yours is a right hand drive model I would suggest you search for where the steering column would go through the bulkhead on a left hand drive model. If you are lucky you might just find a rubber grommet on each side. Try lifting the carpets/mats etc on the passenger side.

[ozfrog]

That’s a good point! Yes, my car is a right hand drive one. That’s what Australia does. Former British colony.

But I’m also surprised at how well the carpets in this particular car are still secured. It looks like they have not been disturbed since the car was built in 2006/07. The worst condition of the carpet is the embossing on the 307 numbers on the two front floor mats and they both sit under thick rubber protector mats. The rubber seems to have rubbed off the embossing. The carpet mats and the rubber mats are all genuine Peugeot mats. I’d be very reluctant to damage them, or the carpet underneath them.

I’m also dealing with a significant loss of coolant that has ended up in the carpet of the front passenger footwell. I think it’s been there for about six years, judging on past events. Long story. But I only discovered the coolant last week when I was looking for a place to thread the electrical cable into the engine bay. A wet and dry vacuum cleaner or a few trees worth of paper towels are the best options for getting rid of the coolant that has soaked into the carpet. If I want to remove the carpet from the car for cleaning, it looks like the whole front carpet has to come out. And to do that, at least the bottom part of the dashboard - maybe the HVAC section? - first has to be removed. I might be wrong, but that’s what it looks like to me. I have considered it already.

I suppose that i could just cut the carpet and remove the passenger footwell section, but ugh! Or I could give the whole car to a professional car detailer and let them take care of it. But I wouldn’t know how thorough the job would be, let alone how much it would cost in advance.

Back to the electrical cable job, I’m about to go diving into the footwell of the car. If I’m never seen again, it’s probably because I was able to get down there and in, but getting back out of there was mission impossible!

[MattBLancs]

It depends on location (and I'm not that familiar with 307) but coolant in the footwells could be leaking heater matrix - which replacement of could be the full dashboard out (at which point getting at the bulkhead, routing to a switch blank becomes easier! Hoping that's not what's heading your way as it's a big job!


Just a thought: alternative switch location idea: get a pedal switch and give light bar operation to your left foot, like the old "dip switches" of old.

A switch in this position actually became quite popular for a different task on the 406 Coupes: pedal was wired to the V6 Automatic to supplement the "sport" button. Such is the effect on the car's behaviour with/without the gearbox in Sport, it was worth having it more readily to hand (or rather to foot!) that the teeny tiny button hiding down on the centre console. Credit to Tatsfield of the Coupe forum for his "Tatswitch" mod

[moizeau]

I fiited a light bar to a mate's Mule a while ago. Same thing, wanted it to opereate from the high beam but not all the time. Wired it old school splicing into the high beam feed to the lights, sent through a relay which fed a inline fused 12v feed to the bar. I just put a toggle switch pre relay in the engine bay

[ozfrog]

It depends on location (and I'm not that familiar with 307) but coolant in the footwells could be leaking heater matrix - which replacement of could be the full dashboard out (at which point getting at the bulkhead, routing to a switch blank becomes easier! Hoping that's not what's heading your way as it's a big job!

I’m not even thinking about that!

I started this thread, so I presume that I’m allowed to take it way off topic.
Here goes …

I’ve alluded to the problem with my first 306 cabriolet. Now might be the time to get it out.

I think it was my wife who saw it advertised on Facebook Marketplace, but whoever it was, knew that she would not drive a manual. She grew up and got her driver licence in the U.S., and manual cars there are an unknown phenomenon! Anyway, the cabriolet was a Phase 2, dark blue, leather interior, one rear window didn’t work, and it was really rough around the edges generally. But the price was right - $500 with almost one year of registration.

The seller was a university student and he worked part time in a car accessories shop, so he had bought a few things and planned to make the car look good. I would have preferred it if he had spent the money on buying a new battery for the car, but that wasn’t his priority. He was honest enough to tell me that the automatic transmission was faulty but it still worked. Just don’t be in a hurry. And he told me that he had bypassed the heater because it leaked into the cabin when it was turned to hot. I thanked him for being honest and I bought the car. It was a great little car!

The AL4 transmission was faulty, but it had nothing to do with being in a hurry. If you drove immediately after starting the car, the transmission would change between first and second gears at random times and speeds. But if you let the transmission warm up before you drove, then it worked perfectly. Even in winter, the transmission didn’t take long to get warm.

The heater was a bit of a problem, but we learned to dress warmly before we went anywhere in the cabriolet. Except for the trip that we were making in warm weather and it was going to be a 5 or so hour drive. It was the first time that we were taking the car out of town. I drove first and I noticed that the temperature gauge was getting a bit high. I said to my wife that we were not in too much of a hurry, so I was going to slow down and see if the temperature would go down a bit. Sure enough, it dropped significantly, and we continued driving. Then we swapped drivers. I reminded her to keep the speed down and to keep her eyes on the temperature gauge.

I don’t think she managed 10 kilometres before the engine ground to a stop. It didn’t want to restart. I called for roadside assistance and they sent a flat bed to take the car. Presumably, if the truck driver had been able to get the car going, he would have taken the flat bed home again, but he couldn’t get the car going, so he put it on the back of his truck and took it and us to a town nowhere near where we were going. And nowhere near anywhere that we could get back home.

Two days later, he was on the phone with the bad news. The engine was seized. And he knew exactly why it had seized. Please enlighten me!

The bright spark previous owner had indeed bypassed the heater. And yes, he had been honest and told me about the problem. What he didn’t tell me was that he had used garden hose to bypass the heater! And, not that it would have made any difference, but he didn’t even use any clamps on the hoses. He just pushed them on.

Unfortunately, we scrapped the car and bought a more recent model. It’s not nearly as good a car. And I’m certain that we have spent more time and money on getting this car right than if we had kept the old one, fixed the engine (and the heater!j and probably the transmission. But hindsight is a wonderful thing.