ARC problem

[dezufo]

Hi, all. Warning light keeps coming on after a short drive. I have read some of the threads concerning this and checked the following;
1. greased the rear sensor/ladder ball conections
2. sensor moves up/down
3. fixed corroded terminal connection on compressor relay
4. shorted out relay connections and compressor runs ok
Have narrowed it down to be NO POWER from module to relay
Is there any way of checking the sensor output to the module and/or checking the module
Its really bugging me

 

[janolsson]

You could do a test for the sensor by un clipping it at one end. Then close all doors and then lay under the truck and compress the sensor to see if it causes the system to kick in.
My ARC light comes on occasionally on motorway journeys but i just ignore it as otherwise the system works fine.
You should aslo check the air lines esp where they enter the shocks to make sure they are in properly.

IIRC jcasey did a thread on the control side of things, so if you search for threads started by him you may find it.

 

[dezufo]

Thanks for reply.
I've tried the sensor up/down already, no joy. Today had a 40 mile journey with a stop at approx 10miles, light came on after a few miles. After 15mins at my stop point I restarted and light went off and stayed off until about 2miles from home, it seems to have a mind of its own. I could not tell if comp ran as its a very noisey road.
Will do a search now.

 

[dezufo]

Update: Problem solved ARC now working as it should, jcasey post on ARC was helpful, though more on the mech side than the electrical side. Had already determined that the solenoids/comp worked, just that the ECU would not turn on the comp.
So with a ford electrical & vacuum troubleshooting manual and a multimeter I set about finding why.

First I checked all the inputs at the ECU i.e. accelerate signal/4wd Hi/4wd Lo/door open/boo switch, unable to check steering and speed sensors for obvious reasons. All inputs OK.

Next I removed load sensor from its hiding place to bench test it. I cut the 3wires approx 50mm from body of sensor, connected these into a terminal strip then connected an old sat nav +5v power supply as well.
Sensor wires; Red = +5v, Black = 0v, White = output
Sensor output in relation to position of actuator rod;
4.73v rod fully in. 0.32v fully out. 1.94v rod in as far as the boot takes it.
So as results showed sensor working correctly there had to be another reason for lack of input at ecu.
Reconnected wiring using red crimp connectors staggered so I could slide the protective tubeing back over. Refitted sensor back onto ball joints.

Rechecked the manual and found out position of loom/connectors associated with load sensor, checked these and found that the multi-pin connector on the chassis rail under front passenger side was suffering from corrosion thus causing volt drop from sensor output, a good squirt of wd40 and a few push in and pull aparts later I felt happy that it would now be OK.
Switched system back on and hey presto comp fired up and we now have lift off.

So ecu has to have input from load sensor for system to work correctly even if other sensor inputs are present and correct.

BTW I needed system to work to cope with an under slung LPG tank and tools of my trade

 

[janolsson]

Great post there and good result.
That may explain my intermittant fault, tho i did replace the load sensor and now it only happens occasionally. I might get under there and clean the plug now and add some dielectric grease.

 

[dezufo]

Great post there and good result.
That may explain my intermittant fault, tho i did replace the load sensor and now it only happens occasionally. I might get under there and clean the plug now and add some dielectric grease.

Did you do it?
Mine is being a sob, the other day it raised the rear by 4inches after parking up and opening the tailgate, something it has never done before, now its reverted to showing warning light after driving approx 12miles. If I had a shotgun I would shoot it!

 

[janolsson]

Did you do it?
Mine is being a sob, the other day it raised the rear by 4inches after parking up and opening the tailgate, something it has never done before, now its reverted to showing warning light after driving approx 12miles. If I had a shotgun I would shoot it!

Not done it yet as it's behavin (fatal last words).
Yours sounds like mine was when i got it. The back end over pumped, being high and bouncy. All it needed was a reset;
1) turn off the system
2) chock front wheels
3) raise both rears off the ground
4) leave to hang for an hour. while hanging check the sensor is attached at both ends
5) lower back down and switch system on
6) ignition on close all windows and doors.
7) ignition off, key out and exit vehicle closing door behind you

The compressor should then kick in and adjust to the correct level.

 

[ihpj]

This ARC system is a pain. I can't wait to tear it out of mine and fit Bilstien shocks all round. Good luck to all those struggling with it and getting it to work.

 

[dezufo]

@ janolsson, thanks I will try that but its behaving itself again.

 

[janolsson]

@ janolsson, thanks I will try that but its behaving itself again.

Something to also think about... Where the ride sensor is located, i would imagine it would be prone to a lot of road spray and dirt. For this reason i would be tempted to revisit your crimped connections and use solder and heat shrink instead.

 

[dezufo]

Something to also think about... Where the ride sensor is located, i would imagine it would be prone to a lot of road spray and dirt. For this reason i would be tempted to revisit your crimped connections and use solder and heat shrink instead.

I thought of that so I made sure the connections would be covered by the tubing and the end sealed with silicone sealer.