- Joined
- Sep 17, 2003
- Threads
- 64
- Messages
- 4,427
- Location
- Sunnyvale, CA
- Website
- www.george4wd.taskled.com
So, I'm sitting in the car waiting for my wife who is yapping to a friend. I have the engine running and figure I might as well "play" with the switches to relieve the boredom...
First one - the CDL dash switch. Click in, no ABS light, no CDL light. Oh great, something to really have to play with... It's late in the evening, so a job for tomorrow.
Today, key in ignition switch on, engine off. Push in the CDL dash switch, relay clicks, CDL actuator whirrs. Check all the fuses, all functional. So, pull the harness of the front xfer box CDL switch/sensor and jumper it across. Turn ignition to on and the ABS light and CDL light are both on.
Ok, must be dead CDL switch/sensor. Remove it with a big spanner and meter it, push in the ball end - open circuit. Tap it on a big vise a few times, meter it, still open circuit. WTF, being an EE I brought my years of expertise into action and put the switch on the vise - with one flat of the hex and HIT the opposing hex side a few times like I meant it with the handle end of the spanner.
Meter it while pushing in the ball end - 0 ohms, release the ball end, open circuit. Reinstall, ABS and CDL lights come on just as they are meant to when the CDL switch is pressed and the actuator locks the CDL.
Here's a couple of pics of the CDL sensor/switch for reference. I'm guessing that since it's a sealed switch and hardly likely to see any contact wear due to high currents that contacts had just oxidized or something like that. Will be interesting to see how long it stays good and if it does fail at some point I'll get a new one and dissect the old one to see what kind of crap contacts are in there.
I've labeled the hex surface that I hit.
george.
First one - the CDL dash switch. Click in, no ABS light, no CDL light. Oh great, something to really have to play with... It's late in the evening, so a job for tomorrow.
Today, key in ignition switch on, engine off. Push in the CDL dash switch, relay clicks, CDL actuator whirrs. Check all the fuses, all functional. So, pull the harness of the front xfer box CDL switch/sensor and jumper it across. Turn ignition to on and the ABS light and CDL light are both on.
Ok, must be dead CDL switch/sensor. Remove it with a big spanner and meter it, push in the ball end - open circuit. Tap it on a big vise a few times, meter it, still open circuit. WTF, being an EE I brought my years of expertise into action and put the switch on the vise - with one flat of the hex and HIT the opposing hex side a few times like I meant it with the handle end of the spanner.
Meter it while pushing in the ball end - 0 ohms, release the ball end, open circuit. Reinstall, ABS and CDL lights come on just as they are meant to when the CDL switch is pressed and the actuator locks the CDL.
Here's a couple of pics of the CDL sensor/switch for reference. I'm guessing that since it's a sealed switch and hardly likely to see any contact wear due to high currents that contacts had just oxidized or something like that. Will be interesting to see how long it stays good and if it does fail at some point I'll get a new one and dissect the old one to see what kind of crap contacts are in there.
I've labeled the hex surface that I hit.
george.