Hello guys,

Currently I own a Magna TF Altera.

There has been some recent issues with the cruise control and hoping that there could be a solution to this.

During the daylight, the cruise control seems functional however towards the evening or dark and rainy days it will not. It stems that the issue is when the lights are on wither in parking or full lights. I have manage to replicate the fault and it certainly stems from the lights.

The Magna uses the 1157 mounting style globes and I changed the rear lights to LED versions as well as LED for front parking lights. The reason for this is that LED is brighter, it consumes less power where I can use the parking lights in dark areas as the car is a metallic dark navy blue and LED technology will not burn out as easily as the older incandescent globes.

I have heard on the "grape vine" that when a rear globe burns out, the cruise control will not function when the lights are on. Should this be true, it seems that the cruise control has some sort of current sensory threshold so when the current goes below a certain threshold (open circuit meaning lower current) and the lights are on, it will not function. Not to mention that LED globes will produce a false negative in this scenario.

My question to the techies are that is there such a sensor in the cruise control that detects such current drop and if so, how can I adjust that threshold.

If there is another reason, I am open to suggestion.

Thanking you guys and gals in advance.

Kindest Regards

Hello guys,

Currently I own a Magna TF Altera.

There has been some recent issues with the cruise control and hoping that there could be a solution to this.

During the daylight, the cruise control seems functional however towards the evening or dark and rainy days it will not. It stems that the issue is when the lights are on wither in parking or full lights. I have manage to replicate the fault and it certainly stems from the lights.

The Magna uses the 1157 mounting style globes and I changed the rear lights to LED versions as well as LED for front parking lights. The reason for this is that LED is brighter, it consumes less power where I can use the parking lights in dark areas as the car is a metallic dark navy blue and LED technology will not burn out as easily as the older incandescent globes.

I have heard on the "grape vine" that when a rear globe burns out, the cruise control will not function when the lights are on. Should this be true, it seems that the cruise control has some sort of current sensory threshold so when the current goes below a certain threshold (open circuit meaning lower current) and the lights are on, it will not function. Not to mention that LED globes will produce a false negative in this scenario.

My question to the techies are that is there such a sensor in the cruise control that detects such current drop and if so, how can I adjust that threshold.

If there is another reason, I am open to suggestion.

Thanking you guys and gals in advance.

Kindest Regards


LEDs do not draw as much current as normal globes. You may need to install a load resistor inline with each LED globe. I've got V-LEDs in my brake/tail light assembly. These are higher powered (> 7W) each. Haven't tested my cruise control yet. As for load resistors. You probably can buy these on eBay.

Hello vlad,

That was a thought however this would prove to be just a "band-aid" solution.

The additional resistors will draw more current ergo having the parking lights on in the night will take out the battery. There must be a way for the threshold to be adjusted.

You could try putting standard globes back in and seeing if the LEDs really are the issue, or whether something more sinister is going on.

No point doing all that work, only to find the problem still exists.

Cheers

J

Hello JimmyA,

That is a thought and I know what you mean.

As what I said in the top the reason for using LEDS was that I can park my vehicle in an area and leave the parking lights on without taking out the battery as it seems that the older incandescent globes had a habit of doing that.

That is the last resort which then defies the entire purpose going to LED not to mention that I will be back to square one.

just out of interest, i had a rear light out, It was the one that stays on, on the boot. it had no effect on my cruise control and i dont see why the light would have an effect normally??? seems a funny thing to incorporate.

just out of interest, i had a rear light out, It was the one that stays on, on the boot. it had no effect on my cruise control and i dont see why the light would have an effect normally??? seems a funny thing to incorporate.

You have 2 pairs of tail lights, as do I, the OP however only has 1 pair of tail lights. That may be the reason why when one of you 4 blows, CC still works.

I had a problem with mine with the dual filament bulbs.

One of them was buggered and the filaments had fused together, making the car think the brakes were on when the parkers were on

Changing the bulbs fixed it (although I still have problems with the brake pedal sensor)

Tested my cruise control last night on the way home and they work perfectly. I've only got LEDs for the dual circuit tail/brake lights. I also have standard filament bulbs for the tail only lights. The LEDs I use are the V-LED M-SMT high power ones. I've tested many and these are the only ones that have the same fill (same area of wall was lit) as normal globes and are brighter.

the parking lights and headlights have no bearing on cc, or at least they shoudnt.
Only the brake has an effect...to disable when the brakes are pressed. I had a mate who put LED brake lights in and had a problem with it not working properly. Check that you have the correct LED'S in the rear and make sure theres no shorting across brakes/tails.
The CC on my TS is an aftermarket one i installed a month back...when i go LED will wire in the required resistance in the cc circuit not the acual lights. That way it will only draw more current when CC is on. You might be able to fiddle the wiring. Be careful though that you dont disable the brake disabling feature (its a safety issue).

on another note...does anyone know of a brake switch that is active when released? im trying to wire in a cheap feature ro the cluth pedal to cut out the CC when the clutch is pressed

@Daniel, Does your CC brand offer a supplementary clutch switch - or is it unaffordable? I had after-market CC on a TP a few yrs back, didn't need one but there install stuff mentioned a clutch add-on for manual cars.

the parking lights and headlights have no bearing on cc, or at least they shoudnt.
Only the brake has an effect...to disable when the brakes are pressed. I had a mate who put LED brake lights in and had a problem with it not working properly. Check that you have the correct LED'S in the rear and make sure theres no shorting across brakes/tails.
The CC on my TS is an aftermarket one i installed a month back...when i go LED will wire in the required resistance in the cc circuit not the acual lights. That way it will only draw more current when CC is on. You might be able to fiddle the wiring. Be careful though that you dont disable the brake disabling feature (its a safety issue).

on another note...does anyone know of a brake switch that is active when released? im trying to wire in a cheap feature ro the cluth pedal to cut out the CC when the clutch is pressed

I've read on forums that some combination tail/brake LED lights have leakage problems, that is the current from the tail light will leak into the brake light causing confusion with the CC etc. You need a good quality set of LED tail/brake lights. I paid well in excess of $80 delivered from the US (costs about the same and lasts longer than 9 sets of normal globes). I'll take some photos of these and post it here. It only has 20 LEDs but these are brighter than the 48+ SMT LED lights which I had before and returned.