Wiring EB on at start

[pcarlson]

Has anyone wired their exhaust brake switch on the 2500/3500 trucks to come on at start up? I realize it is not programable but just looking to see if I can put a relay into the circuit to energize it anytime the key is turned on.

 

[jelag]

The switch is not a powered switch but is a toggle for a computer input... On the 5. 9's this is a ground circuit to the engine ECM... I assume this is the same... . but I have not traced out the circuit... Since your truck is still under warranty... . I'd leave it like it is... so that later if a problem shows up... they don't try and blame you...

 

[pcarlson]

The switch is not a powered switch but is a toggle for a computer input... On the 5. 9's this is a ground circuit to the engine ECM... I assume this is the same... . but I have not traced out the circuit... Since your truck is still under warranty... . I'd leave it like it is... so that later if a problem shows up... they don't try and blame you...

I already knew it is a momentary switch. I have seen this done on another site and was wondering if anyone here has tried the SPDT/resistor trick to turn it on at start. Once on the switch still functions as normal. I will buy the parts and give it a go as others who have tried this trick seem pretty happy with it.

 

[HBarlow]

I have no idea what the difference is whether ECM/PCM programming or simple wiring or switch differences but cab and chassis trucks are programmed or wired so that once the EB is switched on it comes on again at time of next start up.

If you're going to study wiring diagrams you might consider comparing C&C and pickups to see if there is an obvious difference.

 

[ScottLewis]

On my '06 5. 9, I used a simple switch from Radio Shack to replace the stalk switch. I leave it on all the time unless I have a particular reason not to want the brake engaged. Your 6. 7 uses a slightly different processor and wiring diagram so I can't give you really solid advise. I tried to adapt and rewire a 6. 7 dash switch but I finally gave up that idea. You may want to consider jelag's sound advise.



Dan

 

[pcarlson]

Ok I found the instructions I was looking for and I copied them below: (Please give you opinion. ) NOTE: These are not my instructions or idea.



Here what you'll need to have an Automatic EB Switch:



1 relay with SPDT ( Single Pole Double Throw )

1 resistance 15 ohms

16 ga wire

1/4'' female straight connector with plastic isolator ( to connect on the relay )

16 ga TAP connector ( the blue ones )



Here's the way to do it:



1. Tap 1 piece of wire from the PINK/Yellow wire on the cigar lighter to pin 85 on the relay

2. Tap 1 piece of wire from the Black/Yellow wire on the cigar lighter to pin 86 on the relay

3. Tap 1 piece of wire from the Violet/Brown wire from the EB switch to pin 30 on the relay

4. Tap 1 piece of wire from the Brown/Orange wire and connect the other end of the wire to the 15 Ohm resistor

5. Connect the other end of the resistor to pin 87a on the relay

 

[Simplysmn]

Y not just hit the switch an safe yerself a hassel ?????????

 

[pcarlson]

Y not just hit the switch an safe yerself a hassel ?????????

The problem is when the wife drives it she forgets to turn it on. From what I see on here not using it can cause issues and I would like to avoid that. Plus this winter if I use the remote start I would like for the EB to come on. This is just an idea that I will give a shot.

 

[Simplysmn]

I have not seen any problem's in not useing it and I drive my truck everyday with n without EB on but I understand what yer saying just trying to make sure nothing happen's

 

[pcarlson]

It Works. Switch will still turns the EB on and off as well. Just start the truck and the switch comes on.



With remote start the EB will not come on as it is wired to an ignition switched wire and will not come on until you turn the key. But I did find that it got cold here overnight and I found that the EB comes on at idle with the switch off, so regardless of whether the switch is turned on or not the EB works if it is cold out. Must be ECM programming that handles that part.

 

[HBarlow]

Congratulations. From my point of view that is a significant improvement in your overall driving convenience and satisfaction with the new truck. If my truck was a pickup instead of a C&C I would be printing out your instructions and headed for Radio Shack today to buy the components needed.

In over eight years and over 600k miles of Dodge-Cummins ownership I have never driven without an exhaust brake.

Some entrepreneurial TDR member should package the parts and instructions and sell it as a kit for everyone with an ISB6. 7 pickup. I would use the slogan, "don't leave home without it. "

Afterthought: You should send that post to Robin@TDR or post it again in the handy tips section of the website. IMO it should be considered for publishing in the next TDR magazine. Write up the detailed instructions in a complete and easy to follow manner and send it in.

 

[pcarlson]

Thanks Harvey, I view it as an improvement as well. I never drive without it and now my wife cannot forget to turn it on:-laf.



With less than $10 for parts and 20 minutes to solder and install I think most will find it a cheap and quick solution. The hardest part is pulling the center benzel off.



Relay from Autozone - PN 012861 SPDT relay $5. 99



Resistors from Radio Shack - PN 2711102 5 Pack of 15 ohm resistors $0. 99



I had heat shrink for covering the resistor, wire, wire taps and insolated female connectors

 

[CHegreberg]

Great idea. With only 235 mi on my 09. I find it a pita to turn it on everytime I start it up. I forget most every time untill I need to stop and then turn it on. I am a little concerned about tapping into my new truck, but Im sure I:-laf will get over that soon!!

 

[mpaulson]

Hey,PCARLSON, if one takes the line that is trigering the relay for the cigar lighter(either PINK/YELLOW or BLACK/YELLOW) and connected it to a power source that does come on with the remote start, that would do the trick. With my remote start, the radio and lights come on, so I could tap into those power wires and them the exaust brake would come on at start up either way,remote or key, reguardless if it is cold enougth for the ecm to decide to turn it on. I'm going to try this in the near future. Does this make sense?

 

[pcarlson]

MPaulson,



If you find a different wire let me know as I will switch mine around so the switch is on with remote start. I did not do any digging yet to see which wire I could use so if you find the right one let me and the rest of us know. So far the way it is wired currently it works like a charm but on with remote start would be even better.

 

[pwr2tow]

I can see your wife starting your truck and taking off on a nice icy/slippery day, in that case your instant on EB at startup might not be such a good idea when she slows down and starts spinning in circles causing damage to your truck and possible her or anyone else on the road.

Just thought I would throw that out there for anyone interested.

 

[pcarlson]

I can see your wife starting your truck and taking off on a nice icy/slippery day, in that case your instant on EB at startup might not be such a good idea when she slows down and starts spinning in circles causing damage to your truck and possible her or anyone else on the road.



Just thought I would throw that out there for anyone interested.

Very good point. Thought about it and she really doesn't like driving the truck due to visibility. Also she is the type to wait till the next day to go out if the weather is bad, god bless her. And just to be sure I leave a note posted, "If slippery out turn EB off before driving". Let's hope nothing like this happens to any of us.

 

[RDHamill]

Anyone try the same relay and resistor to do an auto on seat heater ? might be worth a try for those with remote start.

 

[mpaulson]

Good question, I was wondering about that yesterday in fact also. I've done the E-brake one and wondered if it is a simple as checking to see which wire gets the current when you hit the button and do the same thing as the E-brake. I'm too chicken to try it as the "what if's" concern me. Would a constant current from this idea be bad for the computer that controls it? I would add a small toggle switch in the line on the dash so that I could just flick it on when I get out of the truck the night before.

Anyone acually done it??? the guy who installed my command start was trying to make this idea work with the trunk button on the remote on another guys truck the same as mine, but couldn't get it to work right, it would just stay on all the time.

 

[Brian Sullivan]

Be careful on ice I was driving across the up with my bran new 4x4. Going down a grade on ice and lifted my foot off the go petal and went down the hill sideways. Managed the stay out of the ditch but was a scary ride with new truck. The engine brakes work very well.