How do you "Jumper the CMU" for LED's bulbs to prevent the warning light coming on ?

Hi Guys,

I'm in the process of upgrading to LED bulbs on one of 86 Venture Royals. I have already converted the headlight and it sure makes a difference.

I have read several articles and forum posts of guys who have already done this and there have been several references made to "Jumper the CMU for headlight, running, and brake lights" so the dash warning indicator isn't constantly lit due to the CMU thinking there is a bulb burnt out caused by the greatly reduce electrical draw from the more efficient LED bulbs. Although there is very detailed info about converting to LED's, I have not been able to find details of what the steps are to perform this "Jumper on the CMU".

Any experts out there who have already performed this "jumper" process on the CMU that could point me in the right direction of which solder points I need to jumper for Headlight and Brake lights?

Thanks in advance!

You install a current limiting resistor, it's value 2000 to 3000 ohms in series. Connect one end of the resistor to the probe lead and the other end of the resistor to the 12 volt accessory line...

You install a current limiting resistor, it's value 2000 to 3000 ohms in series. Connect one end of the resistor to the probe lead and the other end of the resistor to the 12 volt accessory line...

Thanks bongobobny for the reply and the details of the specific resistor I need to use! But I'm rather a novice at this, can you clarify the term "probe lead" to me? Is that the specific solder pad for the headlight or brake light sensor on the the CMU board or is this installed in the wiring before it goes through the CMU? THX!

You install a current limiting resistor, it's value 2000 to 3000 ohms in series. Connect one end of the resistor to the probe lead and the other end of the resistor to the 12 volt accessory line...

if you install a resistor to trick the cpu won't the draw be as bad as having the original bulbs and defeat the purpose of leds?

if you install a resistor to trick the cpu won't the draw be as bad as having the original bulbs and defeat the purpose of leds?

I was getting ready to ask the same thing.

RandyA

I think attached pictures are what you want. These pictures are of an 86-93 CMU, 83-85 CMU's are different. See post #12 below for the 83-85 version.

The 'probe' suggestion earlier is for the battery warning indicator.

Soldering the jumpers shown will eliminate CMU from warning for the high & low beam. Other pictures show jumper positions for brake & tail lights.

Gary

Hmmm, my bad, thought you were asking about the battery warning! Guess the coffee didn't kick in yet...

Is it necessary to jumper the CMU when installing LED brake and running lights? When I reconfigured the headlight on my 90 VR I just removed the RLU and jumpered that connection which is far easier than soldering the CMU.

Yup Bob needs more coffee........

It depends.

If you converted to LED headlight, some (not all) of the LED headlights draw as much or more power than the stock headlight, so no jumpering or other changes need to be made, IF you are installing one of the high power LEDs in the headlight. IF you are installing a lower power LED in the headlight, then you will need to jumper the CMU and remove the RLU to get proper operation.

If you convert the running and/or brake lights to LED, the running and brake light sensors will need to be jumped in the CMU if you do not want it to be continuously telling you that you have a bulb out.

The whole load resistor thing is to get the turn signals to flash at the correct speed when the turn signals are upgraded to LED.

Thanks Gary, this is exactly what I needed. A picture is worth a 1,000 words! Much appreciate the clarification.

I think attached pictures are what you want.

 

The 'probe' suggestion earlier is for the battery warning indicator.

 

Soldering the jumpers shown will eliminate CMU from warning for the high & low beam. Other pictures show jumper positions for brake & tail lights.

 

Gary

So Gary the 1st pic is all I need to do to jumper the high AND low beam, OK, the other pics confuse me, I'ma monkee see monkee do electrician.... I don;t have to understand WHAT I'm doing so much as doing the correct thing....so in a pic like the first one could you show where the jumpers go please?

So Gary the 1st pic is all I need to do to jumper the high AND low beam, OK, the other pics confuse me, I'ma monkee see monkee do electrician.... I don;t have to understand WHAT I'm doing so much as doing the correct thing....so in a pic like the first one could you show where the jumpers go please?

It appears you have 83-85 Ventures looking at your profile. The 83-85 CMU is different than the 86-93 CMU.

I don't have a picture with the jumpers shown. What I have is attached picture that shows location points for the jumpers though. It was done several years ago by a member here.

You would solder a light gauge wire, probably about 18 gauge, between each of the points noted. This will be 4 separate jumpers. One end of each going to the circuit board terminals called out. I sketched them in red highlight.

One picture without highlighted jumpers and other with them.

Gary

OK,I understand the diagram--where would I find the CMU--LOL--Thanks. Oh,I have a 92 VR.

OK,I understand the diagram--where would I find the CMU--LOL--Thanks. Oh,I have a 92 VR.

The thing in your dash that has an anoying red blinking light, sometimes tells you you have no gas and lets you know your kickstand is down. That is the CMU...Computerized monitoring unit...

The CMU is mounted on the dash panel... Take out panel, flip over and unplug the connectors, unscrew the screws holding unit to panel, take CMU out. Use Dingies pics above to solder across the points carefully. When done, you will be able to change all bulbs to led and not have any warnings.

For the headlight, you need to jumper the RLU..... Reserve lighting unit. Black thing mounted in same area as dash. Right in front under windshield. Disconnect the connector. Jumper the connector as per my post last week. 4 jumpers. Now the RLU is no longer in circuit and the computers are happy campers.

The CMU is mounted on the dash panel... Take out panel, flip over and unplug the connectors, unscrew the screws holding unit to panel, take CMU out. Use Dingies pics above to solder across the points carefully. When done, you will be able to change all bulbs to led and not have any warnings.

 

For the headlight, you need to jumper the RLU..... Reserve lighting unit. Black thing mounted in same area as dash. Right in front under windshield. Disconnect the connector. Jumper the connector as per my post last week. 4 jumpers. Now the RLU is no longer in circuit and the computers are happy campers.

Can you get to the RLU by just pulling the wind shield off. I am at a loss for where this board is.

Can you get to the RLU by just pulling the wind shield off. I am at a loss for where this board is.

No but the Reserved Lighting Unit (RLU) can be accessed by pulling the headlight.. Would you like a short video of such?

if I recall correctly, you need to pull the windshield and the headlight bezel off to access the RLU, it is located behind and above the headlight. Also refer to the previous post from videoarizona with the link in it to see which wires that need to be connected together for everything else to keep working properly.

Good luck

Rick F.

No but the Reserved Lighting Unit (RLU) can be accessed by pulling the headlight.. Would you like a short video of such?

You need ask, of coarse a video would be helpful because I have been in there but don't recall seeing anything like that. Of coarse there is a lot there to look at.

You need ask, of coarse a video would be helpful because I have been in there but don't recall seeing anything like that. Of coarse there is a lot there to look at.

Hot off the press and just for you Geo (I used to have a buddy named "George" who had the name tag on his shirt shortened up by an errant disc grinder and what was left was "Geo" = his nickname from that day forward was GEEEEE - OHHHH so thats what I call you in the vid - hope thats ok?)!!! Hope this helps in some small way!!

Puc

DID YOU SAY HOTDOG TIME:fingers-crossed-emo

Hot off the press and just for you Geo (I used to have a buddy named "George" who had the name tag on his shirt shortened up by an errant disc grinder and what was left was "Geo" = his nickname from that day forward was GEEEEE - OHHHH so thats what I call you in the vid - hope thats ok?)!!! Hope this helps in some small way!!

Puc

 

 

That was extremely helpful. I have to get more proficient with that. If a picture is worth a thousand words a video is worth a million. I am thinking all you did was post up a utube video and then copy and past the link in your post.

Putting a face to a poster is one thing but that video was the best. I had the bike out tonight for the first real ride of the season and was just so impressed with how good it ran but then I always am when its running right. The new vacuum boost clearly fixed the original problem and the new TCI had it running on cylinders again. Disconnecting all the accessories charges also seems to have ended the battery drain also. Now I am thinking of all the other things I wanted to do like the new brakes or vmax heads and nitros. Well maybe we will wait on that but when everything is working I just love this bike.

I had to laugh when I saw your bike. i guess with all the stickers you not much worried about cleaning the bugs off. I saw the sleeping bag tied to the seat and had to laugh since my wife and I travel with self inflating air mattresses tied on to the luggage rack. People ask us if we are traveling and we have to tell them no we just like to nap comfortably during our day trips.

I think attached pictures are what you want. These pictures are of an 86-93 CMU, 83-85 CMU's are different. See post #12 below for the 83-85 version.

 

The 'probe' suggestion earlier is for the battery warning indicator.

 

Soldering the jumpers shown will eliminate CMU from warning for the high & low beam. Other pictures show jumper positions for brake & tail lights.

 

Gary

Here is how I jumpered my 1990 XVZ1300DA CMU

This is how I plan to Jumper the RLU Molex:

I've seen several different versions of how to jumper the RLU and I think each one of them is different because all contributors have different year/model of Venture Royal. Mine is a 1990 XVZ1300DA.