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What would cause neither part of cruise control switch to light, I mean the green symbol doesn't light nor does the orange on indicator, I have changed switch, cruise control works fine and I have tested bulbs and there OK but it just doesn't light

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Dirty contacts on the bulbs or the plated strip that they run against. With the switch pulled out you should be able to twist the bulbs with a small screwdriver, work them back and forth and you should clean the contacts up. If the other switches light up with the sidelights on,then that one should too. If the ground was missing the cruise wouldn't work.

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Yeah I thought same bud but neighter switch lights up but I check bulbs and they are good also the contacts they sit against look ok

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Rave shows pin 2 of the connector is used for the lamps (backlight) on the diesel version, this is the RW cable (Red and white at a guess?).
Pin 6 is shown for the status lamp

Theres a full circuit diagram in the ETM section of the P38 Rave which might help you see what should be connected, and does describe how the system works as well, screenshot of the relevent page is below

enter image description here

It wouldn't be a bad idea to check for 12v on those two pins, as shown it shares a ground for all 3 functions of the switch, so unless theres something wrong with the loom on those two pins, there isn't much else that can cause it. Unless both switches are faulty, which is unlikely??

Pin layout below

enter image description here

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Also if the ground looks like it might be an issue, then the connector for it is in the footwell, E252 is behind the kick panel near the drivers door. As said, unlikely its that as the cruise wouldn't work if it was missing.

It might help to add your vehicle details (year, fuel type) to your signature as well.

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18996 2.5 diesel auto bud, also the green suspension inhibitor doesn't light either bud orange on light does

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How are you testing the bulbs? I had to replace at least half of mine as they were blown. A squirt of contact cleaner on the contacts and in the hole the bulb fits into cleans them out nicely and makes them light up much brighter.

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Continuity on multimeter

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The ETM shows the same RW wire on pin 2 of that connector for the backlight. I'd guess you don't have 12v on either of them with the lights on?

There is a diagram of the whole circuit for both switches in the ETM, Unless someone else comes back with a common failure point your probabbly looking at tracing that back to see where the 12v feed is being lost. It shows you the various connectors and such in there. Gillbertd has posted a link to the download for Rave previously on here.

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Thanks bud I'll maybe get dash front out for a look

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i was just thinking someone has fitted aftermarket kenwood stereo in car i wonder if they damaged cable to switches or tapped into it for +12v supply, i just wouldnt be hard to rule it out

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As far as i know the P38 uses standard connectors for the stereo so they shouldn't need to alter the plugs. That wouldn't rule out them having trapped a wire somehow or having done something odd and would be a good place to look as its been altered. There is usually an illumination feed to the stereo power plug even if it isn't actively used by the head unit fitted.

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i was told to look at becm but when i checked online the only couple plugs i seen mentioning illumination and switches also powered interior light, gear lever light, cig lighter lights etc and there all working fine so i think it can kindoff discount them and narrow down to more local to switches/stereo i think

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The info in Rave is from the manufacturer and far more detail than you will find elsewhere. Stereo and multimeter should allow you to narrow it down somewhat, if you look at the wiring diagram at the same time you can check each point to see where the problem is.

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im hunching my bet its behind dash/stereo area, i would think all the buttons will get same power supply upto a point then it will branch off to each switch or thats my thinking

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It's the same Red/White wire that feeds the illumination power to all the switches. So if one lights up and another doesn't, there's a break somewhere.

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i found the probelm, it turns out the bulbs are infact blown, i took orange bulb out fog light switch and tried it in all the others that wasnt working and they worked after i took dash apart so see if any problems behind there and there was none so i need 2 green and 1 orange of what ever bulbs the switches use

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Already told you in your other thread. For the dashboard switches, green bulbs for the illumination are STC1878 while amber bulbs to show it is switched on is STC1877.

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i know bud but the price seems stupid for something that bloody small lol

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Orange ones are cheap enough https://www.lrdirect.com/STC1877-Bulb-And-Holder-Switches-Orange/, green ones are a bit steep though https://www.lrdirect.com/STC1878-Bulb-And-Holder-Switches-Green/