4x4 no low range
#1
04-13-2015, 12:46 PM
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4x4 no low range
On my 99 f250 with 6 speed manual and electronic shift...I can't get low range with the switch. Put in new switch, still no low range.
I read on this forum that to test the safety switches you can jump across 2 relay terminals and see if it goes in. So I did, went in just fine.
How do I determine which safety switch is not working?!?
I read on this forum that to test the safety switches you can jump across 2 relay terminals and see if it goes in. So I did, went in just fine.
How do I determine which safety switch is not working?!?
#2
04-13-2015, 08:10 PM
#7
04-14-2015, 09:53 AM
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#8
04-14-2015, 10:01 AM
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Yea I got a code scanner. Not showing any codes.
Let me get this straight..to get into 4 low I have to have my foot on the brake and the clutch, truck in neutral, and be at a stop...?
I think my switches are working because the 4x4 switch is brand new, the brake, clutch, and slipping the truck into neutral all disengage the cruise control..
Only thing is my speedometer don't work. Reads zero at any speed...but my odometer and cruise work just fine...
Any way to bypass all safety switches??
Let me get this straight..to get into 4 low I have to have my foot on the brake and the clutch, truck in neutral, and be at a stop...?
I think my switches are working because the 4x4 switch is brand new, the brake, clutch, and slipping the truck into neutral all disengage the cruise control..
Only thing is my speedometer don't work. Reads zero at any speed...but my odometer and cruise work just fine...
Any way to bypass all safety switches??
#9
04-14-2015, 10:19 AM
Kind of, to go into 4 low both the clutch and brake must be depressed and you must be moving less than 5km/h (3mph). On a manual it is not required to be in "neutral".
It does seem that all of your switches are working, but it seems like your speed input may be the one causing the issue. Can you watch the vehicle speed from the OBDII port?
The best we can really do for bypassing all the safety switches is to jump across the relays like you mentioned doing earlier.
Baatzy
It does seem that all of your switches are working, but it seems like your speed input may be the one causing the issue. Can you watch the vehicle speed from the OBDII port?
The best we can really do for bypassing all the safety switches is to jump across the relays like you mentioned doing earlier.
Baatzy
#10
04-14-2015, 10:37 AM
From another thread, complements of cleatus12r.....
The test Cody gave us above proves out everything on the power side of the 4x4 system. I am guessing your method was slightly different than the one above, but it yielded the same results. Add to that the fact that you can shift into and out of 4HI proves out both your hi to low relay and low to high relay.
This, along with the fact that your speedometer doesn't work makes me think you have an issue on your control side, specifically with the speed input part.
Baatzy
Easy test for the wiring coming up........
It takes a test light (with an incandescent bulb) and nothing more.
1. Remove the cover from the bottom of the auxiliary relay block.
2. Connect the ground lead of the test light to ground.
3. Check for B+ at the two green wires on BOTH relays (Terminals 86 and 87) as they should have power at all times.
4. Touch the test light probe to terminal 85 on either relay. That relay should click and you should hear the motor try to do something. Try the other one.
5. If nothing at all happens, then you have a relay problem (but you've already switched them out I think). If the relay clicks and the motor doesn't move or groan, then there's an issue between the relay and the motor or an issue between the relays and G100. The ground issue is easily checked by putting the test light clamp on the positive battery terminal and checking to see if it lights up on terminal 87a of each relay connector terminal (with the relay unplugged).
If everything works with the test light method, then you need to look upstream to the 4WD module. The 2Hi/4Hi doesn't care what the vehicle is doing (IE, vehicle speed, brake switch state, et al). If your relays do something with the test light, you need to look toward the control side, not the relay/motor side.
It takes a test light (with an incandescent bulb) and nothing more.
1. Remove the cover from the bottom of the auxiliary relay block.
2. Connect the ground lead of the test light to ground.
3. Check for B+ at the two green wires on BOTH relays (Terminals 86 and 87) as they should have power at all times.
4. Touch the test light probe to terminal 85 on either relay. That relay should click and you should hear the motor try to do something. Try the other one.
5. If nothing at all happens, then you have a relay problem (but you've already switched them out I think). If the relay clicks and the motor doesn't move or groan, then there's an issue between the relay and the motor or an issue between the relays and G100. The ground issue is easily checked by putting the test light clamp on the positive battery terminal and checking to see if it lights up on terminal 87a of each relay connector terminal (with the relay unplugged).
If everything works with the test light method, then you need to look upstream to the 4WD module. The 2Hi/4Hi doesn't care what the vehicle is doing (IE, vehicle speed, brake switch state, et al). If your relays do something with the test light, you need to look toward the control side, not the relay/motor side.
This, along with the fact that your speedometer doesn't work makes me think you have an issue on your control side, specifically with the speed input part.
Baatzy
#12
04-14-2015, 12:57 PM
The control side is all of the inputs, such as brake pedal position switch, clutch pedal position switch, 4x4 switch, transfer case range input, and vehicle speed. It sounds like everything but your vehicle speed input have been verified as working.
It could be your GEM or it could be your vehicle speed input.
I will send you the troubleshooting manual for the '99.
Baatzy
It could be your GEM or it could be your vehicle speed input.
I will send you the troubleshooting manual for the '99.
Baatzy
#14
04-26-2015, 01:15 PM
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Well..not sure yet. Went through the troubleshooting process...GEM does not read clutch switch engaging. Haven't looked into it further than that yet until I can find a wiring diagram or trace wires.
So it's either gem or clutch switch..
Also speedo don't work, it has a wiper code(they work) and a brake switch code...so do they all point to gem or what?
That's where I'm stuck
So it's either gem or clutch switch..
Also speedo don't work, it has a wiper code(they work) and a brake switch code...so do they all point to gem or what?
That's where I'm stuck
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