Turbo Failure

[dieselshadow]

Anyone that tows and plugs in the 7 way harness from the trailer may have noticed that upon restart, the EB automatically stays on if it was turned on previously. I read a few years back that someone had purchased a replacement 7 way connector and made a jumper connecting (I think), the brake lug and ground insude tge dummy connector. The dummy 7 way is inserted into the power port in the bed of the truck. This fools the truck into thinking there’s a trailer attached and will allow the Tow/haul and EB settings to remain on at each start up.

I would think the jumper your talking about would be a problem. That’s a direct short to ground on the brake circuit. But I haven’t tried that and don’t have experience to say exactly, it just doesn’t seem right. Maybe a resistor or something else like a different jumper configuration?

 

[Minnow101]

I would think the jumper your talking about would be a problem. That’s a direct short to ground on the brake circuit. But I haven’t tried that and don’t have experience to say exactly, it just doesn’t seem right. Maybe a resistor or something else like a different jumper configuration?

Yeah I don’t have specifics. All I remember is the guy said this hack worked for him. Personally, I’ve been turning on the EB & T/H on every time I start the truck since new so its now muscle memory type of thing for me.

 

[josephc1]

Automatically turn on TH & EB every time the truck starts.

 

[Wiredawg]

Even with the weather in the 100s, I still let the truck idle a minute or so. With that dead time, I'm running a preflight checklist always, first verifying oil pressure, startup dash lights go out, EB icon lit, preset aux switches lit for cb/cameras, and check pressure gauge for onboard air compressor. If my EB didnt automatically stay on, I would turn it on at this time.

I'm not sure I would try to fool the system into thinking there is a trailer connected just to avoid turning on the EB. The truck uses trailer plugged in to affect other systems on the truck.

Best thing might be to add turning on EB at startup while idling. I'm trying not to be insensitive to those whose EB DOESN'T stay on automatically, but if that's the worse thang you're dealing with, just enjoy that mighty Cummins, that pertty truck and SMILE.

Cheers, Ron

 

[AH64ID]

Anyone that tows and plugs in the 7 way harness from the trailer may have noticed that upon restart, the EB automatically stays on if it was turned on previously. I read a few years back that someone had purchased a replacement 7 way connector and made a jumper connecting (I think), the brake lug and ground insude tge dummy connector. The dummy 7 way is inserted into the power port in the bed of the truck. This fools the truck into thinking there’s a trailer attached and will allow the Tow/haul and EB settings to remain on at each start up.

Mine seems to remember more if I use the bumper plug, but not the bed plug.

The only time it remembers with the bed plug is when I use remote start.

 

[SnoKing]

"Search Results
Featured snippet from the web
A 7 inch brake magnet should have 3.8 to 4.0 ohms of resistance and 10 and 12 inch brake magnets should have 3.2 to 3.5 ohms of resistance. If the resistance is not as specified the magnet needs to be replaced. You can also check the magnet with a 12 volt battery. "

One of the first things I learned in 26 weeks Electronic Technician A school in the USCG in 1965 was:

OHM's Law and how resistors work:

Resistors in parallel lower the over all resistance.
Resistors in series increase the over all resistance.

Trailer brake magnets are in parallel.

3.2 divided by 2(magnets/single axle) is 1.6 ohms
3.2 divided by 4(magnets/two axle) is .8 ohms
3.2 divided by 6(magnets/three axle) is .533 ohms

So the resistance is quite low. I would start with a 10 or 20 watt 1 ohm resistor. Or use a single old brake magnet, which might not be enough resistance however, and give error or not active the controller. Somewhere you have to disburse the energy and into the wiring directly would not be the best. The RAM integrated brake controller would most likely indicate a dead short and go off line, if you just jumper the brake lead to ground lead.

 

[Wiredawg]

Goode Ole Dr Watson and Mr Ohms

Couldn't resist (ohms law) Must be a short between my ears.

Chee-eers, Ron

 

[SnoKing]

OHMs law is E=I*R

Where:
E is Voltage
I is Current
R is Resistance

If we want to know current then it is:

I=E/R

So lets look at the axles noted in my earlier post. I will use 12V just as a reference, as voltages at the brake magnets can very depending on the wiring used.

Single axle
12/1.6=7.5 amps
Two axle
12/.8=15 amps
Three axle
12/.533=22.5 amps

Assuming a perfect world, each magnet would have the same amount of current flowing. And that helps to explain why a lighter trailer needs the controller turned down and a heavy trailer needs it turned up.

 

[DeansRedRam]

If I have a trailer hooked up my 18 will keep the smart exhaust brake on throughout key cycles.

I will run smart exhaust most of the time when unloaded, but never T/H unloaded, its just too aggressive for me. I almost even find it too aggressive towing my trailer that's only 3klbs. These trucks are really designed for some serious weight capacities.

 

[SnoKing]

If I have a trailer hooked up my 18 will keep the smart exhaust brake on throughout key cycles.

I will run smart exhaust most of the time when unloaded, but never T/H unloaded, its just too aggressive for me. I almost even find it too aggressive towing my trailer that's only 3klbs. These trucks are really designed for some serious weight capacities.

This last round trip to Arizona with our 8K bumper pull TT, I ran without TH a lot to allow the transmission to shift to 6th without having to go over 65 like in TH. Got better mileage that way. At 60 MPH in 5th the 8K trailer got about the same mileage as the 16K 5th wheel.

 

[Cummins12V98]

Trailer plugged in EB is automatically on with my 15.

 

[DeansRedRam]

This last round trip to Arizona with our 8K bumper pull TT, I ran without TH a lot to allow the transmission to shift to 6th without having to go over 65 like in TH. Got better mileage that way. At 60 MPH in 5th the 8K trailer got about the same mileage as the 16K 5th wheel.

You got the same mileage towing 8k vs 16k?

I kind of understand that, and even though I have never towed that heavy consistently with my truck to get some facts but I believe it.

My mileage drops from about 22 to about 14-15 pulling my 7x12 enclosed, which only weighs about 3klbs, and I feel thats a significant drop in MPG, but at the same time I think my mileage would be around 14-15 pulling up to 7k lbs. Its a weird concept to think about the way I do.

 

[SnoKing]

16K 5th wheel sits up close to the truck cab. The TT is way behind the truck and bikes of mounted on the BakFlip bed cover. TT has squared off flap back and 5th wheel has a rear cap.

 

[Wiredawg]

I get about the same fuel mileage towing my 20 ft enclosed car hauler with 5KLb tractor as with my 21Klb 5th wheel. The car hauler has square front with ~14ft open space between the back of the cab to the face of the trailer and 5er has nice aerodynamic frint only a few feet behind the cab, even though much taller.

At least in my case, aerodynamics TRUMPS weight affecting fuel mileage.

Cheers, Ron

 

[SnoKing]

Same Same

 

[AH64ID]

I get almost the exact same mileage towing a 11K 26' Toy Hauler, 9K 30' TT, or 10K 5th wheel.

 

[SnoKing]

I get almost the exact same mileage towing a 11K 26' Toy Hauler, 9K 30' TT, or 10K 5th wheel.

I think if my truck struggled to tow the 16K trailer I might see more of a difference, it does not struggle! So towing in the same gear (5th gear) and speed there is very little difference. Getting into 6th with the little trailer as I noted, does improve mileage. We will be off to Arizona in 5 weeks, so another chance to test theories. Taking the higher elevation route down through the middle of Nevada.

 

[AH64ID]

I think if my truck struggled to tow the 16K trailer I might see more of a difference, it does not struggle! So towing in the same gear (5th gear) and speed there is very little difference.

I don't feel any real difference with the 3 effort wise, but then again that translates to the same milage. No struggles, 6th above 65 until the grades hit.

 

[DeansRedRam]

Interesting. When I first got my little 7x12 V nose I felt that it was heavier than 3k lbs, but I correlated that to just wind resistance as you guys have stated above.

 

[TSandner]

Mine is a 2008. I just changed my turbo at 255,000mi. I always run the EB. My turbo had not completely failed yet but it was showing signs like the EB sticking on and taking a few seconds to allow acceleration again. I put a BD Diesel reman on it. The reman turbo cost me ~$1,500.00.