Nearing the end of a 5k mile trip and my exhaust brake quit. Backed off the accelerator and the exhaust brake light came on as normal momentarily then a series of clicks, a flickering light and it went out. Hasn't functioned since then. Figure it's the switch connected to the accelerator pedal since I wasn't touching either the clutch or the shifter, both of which have exhaust brake switches. The 'warm up' exhaust brake feature doesn't work either. I'm assuming the system thinks the accelerator is still pressed down since the switch is not activating. The manual for a 99FG which I have shows a switch similar to the clutch exhaust brake switch and brake light switch mounted pointed up which the accelerator pedal hits when released. I can't see such a switch. I see a hockey puck kind of plastic switch (smaller than a puck) which a lever connected to the accelerator mechanism. Is this the exhaust brake switch? Does that switch do something else also? I haven't been able to feel a cable attached to the accelerator under the dash.
Exhaust brake accelerator switch?
- Thread starter kerry
- Start date
Ok, some more reading on 'minor changes to 99's' reveals that the 'hockey puck' switch is the accelerator position sensor which sends a signal to the electronic governor. There is no cable between the pedal and the IP. Also, I see that the problem may lie with the exhaust brake relay and not the pedal sensor. This now seems more likely to me since the accelerator seems to be working correctly otherwise. Anyone know exactly where that exhaust brake relay is located?
gait
Explorer
not much help with the location of the relay sorry.
a bit of diagnosts I once used on a Toyota was to attach a multimeter to clutch and/or brake switch. When the pedal conditions for switching the retarder are met (foot off accelerator, foot off clutch) the volts will change somewhere. Doesn't account for all the other conditions (engine running, in gear, vehicle moving). The warm up switch has some conditions for operation the same as normal but I've never completely identified them. Silly question, do you have power to the circuit?
a bit of diagnosts I once used on a Toyota was to attach a multimeter to clutch and/or brake switch. When the pedal conditions for switching the retarder are met (foot off accelerator, foot off clutch) the volts will change somewhere. Doesn't account for all the other conditions (engine running, in gear, vehicle moving). The warm up switch has some conditions for operation the same as normal but I've never completely identified them. Silly question, do you have power to the circuit?
I had failed to do a simple test first. I turned on the exhaust brake warm up system switch and with the engine running pushed in on the clutch disengagement switch. Exhaust brake turned on. So, I screwed in the switch a couple of turns and it operates in the warm up mode just fine now. Haven't driven it yet. So, if you lose your exhaust brake, just reach up with your finger and push that switch in a little further to see if it has worn enough that it doesn't make good contact anymore.