More E-Brake Questions

[SStokes]

I've decided an E-brake is for me. I'm leaning toward the jacobs or dodge. If i understood right, these are the same. A couple of things I don't understand completely. I read on one post about a delay of one or two seconds. Is this only if it is hooked up to operate when you take your foot off the accelerator? Can this brake be hooked up with a direct switch mounted on the shift lever(6 speed)? If not which ones can. I like everything simple. When I press the button the truck slows down. If not maybe I can figure out why. Thanks





Sam Stokes



PS I have a 2001 3500 with a six speed. Never figured out all the signature stuff yet.

 

[klenger]

Dodge and Jacobs brake are the same product. The 1. 5 second delay is generated by the ECM. The ECM outputs 12VDC to the brake servo assembly 1. 5 seconds after pressure is removed from the go pedel. The switch is connected in series with this signal so that the brake can be turned off if desired. You can use the switch supplied with the kit, or install a shifter mounted switch. BD sells one for about $35. IMHO, the 1. 5 second delay is not a problem and prevents the brake from comming on when shifting. Installation is also easier since you don't need to install a mechanical switch on the go pedel. I consider the primary function of the exhaust brake to be to slow the truck down when decending steep grades, and not for panic stops, therefore the 1. 5 sec. delay is not a problem for me. Installation is not difficult at all.



I bought the Dodge OEM e-brake from Mechanicsviller Dodge at 800-559-6698 for $540 plus $12 shipping. Very good service.



Good luck

 

[mbrolin]

I agree with klenger. Purchased my Jacobs from Mechanicsville as well. They had the best price,were knowledgable and shipped immediately. Wouldnt pull my 5er wirhout it.

 

[MikeR]

Like Michael and klenger both said,the 1. 5 sec delay is not a problem. But if you want a direct switch to instant 'ON',than all you do is wire your shift lever mounted switch to a power source and the vacuum servo.

 

[rubberneck]

delay with other ebrakes

can the delay feature be used with only the jacobs brake, or can i use it to replace the pedal activated switch on my bd 4" remote mount brake. where is the conection on the ecm that i want to use to power the ebrake solenoid??

 

[klenger]

Pin 20 of the ECM provides 12 vdc power to the ebrake. You can purchase a pin crimped onto a 6" pigtail wire with a butt splice on the other end to connect to it. I am not familar with how the other brakes are wired, but I'm sure they can be adapted to use the ECM output. The cummins part number for the pin is 3824810. I paid $4. 00 for it.



Here is a picture of the pigtail / pin for the ECM.

 

[G.L. Smith]

I put a switch on the gearshift that overrides the microswitch.

It closes the brake when you flip the switch. The brake works

normal. sometimes when you pull a hill and start down,the brake

dont close when you let off the peddle just flip the switch on the

gearshift and it closes.

 

[rubberneck]

thanks klenger

klenger, thanks so much for the part # on that wire, the guys at the dodge dealership looked at me like i was an idiot when i mentioned it. Said they have never heard of such a wire or connction to the ecm. Said they couldn't cross over the cummins part #, so i found the nearest cummins dealer. $4. 40, and it should be here tomorrow. Now, since i don't have the jacobs, but am planning on wiring my bd in the same manner using the ecm to controll it, i have a question. if i understand correctly, this wire will provide the 12 volt source for the vaccuum solenoid, and will be the sole controller of the brake (besides the manual override switch). i. e. i wont need the throttle pedal switch supplied with my bd correct... . on your jacobs, do you wire the pin 20 wire directly to the vacuum solenoid, or is it triggering a relay, i had planned on using the relay, but if it's not necessary????? thanks in advance. Phil

 

[klenger]

ruberneck:



Here is a link to the installation manual for the Dodge Jacobs brake http://www.jakebrake.com/service/pdf/026275.pdf

Figure 19 shows where pin 20 is and how to connect to it.





The manual from the above link is slightly different from the one I got with the kit, and doesn't have the wiring diagram, but I put the diagram on my web site at http://www.danburypark.org/klenger/tdr/jake-brake-page-10.gif



As much as I hate to sound like a lawyer, I must state that it is your responsibility to make sure that you do this mod correctly. If your mod draws too much current from pin 20 of the ECM, the ECM could be damaged.



I suggest that you measure how much current the brake draws by connecting it to battery power temporarily, and then install an inline fuse from ECM pin 20 just large enough to handle it. Dodge uses a 10 amp fuse, which seems way too high to me. Basically what you are trying to do is to supply 12vdc power from the ECM to the high side of brake solonoid and ground the low side. A switch can be inserted on either the high or low side to disable the brake. A relay could protect the ECM from high current if the solonoid draws high current, but isn't necessay if the current is reasonable.



Keep me posted on how this works out. When you get it done, we could write some instructions on how to do this and post them somewhere (Fritz's site maybe?).



Good luck



Ken Lenger

 

[rubberneck]

wiring diagram

klenger, thanks for the wiring diagram link, that is exactly what i needed. couldn't pull up the jacobs instructions (probably wrong reader or something) but i dont think i will need it. the wiring diagram is perfect though. And i hear you on checking the current draw of the solenoid, will be the first thing i do. from the wiring diagram of the jacobs, it looks as though their solenoid only pulls 0. 83 amps , so i am with you, whats up with the 10 amp fuse????, oh well, i will check the current draw, and will probably just end up putting in the relay anyway, i mean heck they are a he!! of a lot cheaper than the ecm. i will keep you posted, and report back any changes/mods i needed to make to make it all work. hopefully the pig tail will be here tomorrow so i can wire it all up wednsday morning. thanks PHil

 

[klenger]

Here is a copy of Fig 19 from the install manual showing where pin 20 is.



http://www.danburypark.org/klenger/tdr/ecm-pin-20.gif