Tag Archives: ProLink for DDEC II

2014/03/02 (N) Dashboard Wiring

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(Photos of this work are in the gallery post for this date.)

John and Marian returned at 10 AM today.  I unpacked all of the tools again, shut off the power to the pressure switch for the auxiliary air compressor, and removed the cover.  Sure enough, the diagram was right there.  The pressure switch was a Connor designed for air systems.  It was not a water well pump control switch although externally you would not know the difference.  It was designed to allow adjustment for a cut-in pressure as low as 40 PSI and a cut-out pressure as high as 160 PSI with an adjustable pressure difference between cut-in and cut-out of 20 to 50 PSI.  The two large spring-loaded shafts moved the operating range up and down while the smaller single shaft adjusted the differential.  It presumably had the two large springs, instead of the usual single one found in a water well switch, because of the higher operating pressures.

After figuring out a combination of tools that allowed me to turn the adjustment nuts, I backed off (CCW) the two nuts on the large spring shafts equal numbers of turns.  The adjustment rate appeared to be approximately 3.0 to 3.5 PSI per full revolution. I lowered the cut-in pressure, turned the power back on, and bled the auxiliary air tank until the compressor came on.  A little more adjustment and I had the cut-in pressure set to 65 PSI.  That put the cut-out pressure at approximately 90 PSI.  I decided to raise the cut-off pressure to about 95 PSI, a 30 PSI differential, in order to get a slightly longer off-time.  I checked the time with my stopwatch and the compressor was coming on about every 2 hours and running for about 3 minutes.  Not bad compared to the 20 – 25 minute cycle we were seeing before the old compressor died.  In subsequent tests it has stayed off as long as 2 hours 15 minutes if I did not use any air powered accessories.

The 65 PSI cut-in pressure was selected to keep the overall system pressure above 65 PSI.  There is a pressure regulator / water separator that takes air from the auxiliary air manifold and supplies it to the house accessories, specifically the toilet, pocket door, and waste tank dump valves.  The toilet, in particular, wants to see 60 PSI to operate properly.  The auxiliary air compressor also maintains the pressure in the suspension/brake systems, and I like to keep that pressure above 60 PSI.  If not for these minimum pressure requirements I would set the pressure control switch to cycle between 45 and 95 PSI and extend the off-time to 3 or more hours.

With the compressor project wrapped up for now I got out my Pro-Link ECM diagnostic instrument.  The ECM for our DD8V92TA is a DDEC II.  I turned on the chassis batteries and we plugged the Pro-Link power cord into the 12VDC outlet (cigarette lighter) in the driver’s area and plugged the data cable into the diagnostic port in the outside bay under the driver’s seat.  (Note to self:  Install a 12VDC outlet next to the data port for future use.)  After referring to the manual, we were able to examine the data in the DDEC II.

There was one Inactive code set as follows:

MID: 128  Engine  |  Fuel Temp Sensor  |  Input Voltage High  |  I1   PID: 174   FMI: 3

We did not check for active codes as that required the engine to be running and I don’t like to start unless I am going to run it long enough to bring it up to operating temperature.

This was the same code that Bill and I saw in Arcadia and then cleared, so it must have reappeared on the drive back to Williston on January 1st.  I had purchased a new fuel temperature sensor early last year and had our mobile mechanic, Joe Cannarozzi, install it last spring.  It is possible, though unlikely, that this new sensor was bad.  I also do not think I that the bus has a fuel temperature issue.  That leaves wiring or the DDEC II as possible culprits, but not necessarily the only ones.  The fuel temp sensor is mounted in a dry pocket on top of the engine underneath the DDEC II.  I believe the wires go directly from the sensor through a connector to the computer, so the wires and/or connector are obvious places to look for a problem.  More importantly for us today, it appeared that the check engine light has been coming on for a reason, not at random, displaying an active code while driving and coming on and going off as the error condition appeared and disappeared.

Now for the dashboard.  The cover just lifts off, exposing the top and back side of all the gauges, switches, indicator lights, dash lights, rotary controls, and wiring; lots of wiring.  The area behind the dashboard is not very deep—12 inches at most—and it is easier to see this area from outside through the driver side lower windshield than from inside and above.  Extensive work behind the dashboard would require the removal of the driver side lower windshield.

John and Marian studied the wiring through the windshield and spotted some issues.  We followed the wires coming out of the back of the speedometer into a large bundle that went to a large circular connector with a twist-latch to hold it together.  There are several of these connectors to accommodate all of the dashboard wiring, plus smaller connectors for the dashboard lights and miscellaneous power feeds.  (Except for two small air lines for the primary and secondary air system gauges, and some mechanical connections for the front HVAC system, it appears that undoing these wiring connectors would allow the dashboard panels to be removed intact.  That would provide an alternate way to work on the wiring.)

The insulation on several of the wires was abraded or had been chewed off.  (Mice are known to chew insulation off of wires.)  We taped the damaged wires to prevent any further deterioration.  We also noticed a wire that came out of the connector that contained the speedometer wires and looped back into the connector.  It was approximately 6 inches long and the insulation was missing from one side of the middle four inches, exposing the stranded copper conductor.  Not only was that a potential short circuit, the conductor was not in good shape.  It was slightly corroded due to atmospheric exposure and it was frayed in several places with only a few strands providing continuity.  This in turn would look like a resistance to the circuit, causing a voltage drop and reduced current flow.  We clipped out the bad section and spliced in a new piece if wire.

(As a side note, there are only two obvious reasons to loop a wire back through a connector like that: 1) It was intended to go to something that was not installed and then continue on to something else, or 2) It was being used to detect that the cable was plugged in.)

We separated the two halves of the connector and sprayed them with contact cleaner.  While they dried we checked for ground connection problems, but did not see any obvious ones.  The ground on the speedometer mounting bracket looked sound and all of the other speedometer wires were shielded pairs; the instrument itself did not use chassis ground for its signals.

While we had the dashboard exposed I decided to remove the radar detector.  I have never used radar detectors, but it was already installed in the coach when we bought it.  I had never used it and did not intend to.  It was taking up space and making access to things more difficult.  (I had previously removed an electronic compass that did not work and I still need to remove the “musical horn” which we don’t use because it’s annoying.)

With the dashboard work completed we opened up the electrical service bay above the driver side steer tire.  This bay contains a lot of chassis electrical components such as relays, circuit breakers, terminal strips, diodes, and the anti-lock brake computer.  What we were looking for, however, was the Speed Limit Switch (SLS).

The SLS is used on seated coaches to disable the kneeling feature of the suspension when the coach is moving.  In order to do that, the speedometer wires pass through the SLS enroute to the dashboard gauge.  The Prevost national service advisor for conversion shells, Bill Jensen, told me back in January that this switch might be installed in our coach even though it was not used, and that it was a possible point of failure that might cause our intermittent speedometer problem.

The Speed Limit Switch was not present, but there was a DB-15 connector at that location that could have plugged in to it.  The connector was plugged in to a mating connector that did not have any wires coming out of it.  Looking in the cable access hole on the end we could see wires inside.  It was a loop back terminator.  We separated the two connectors and sprayed them with contact cleaner but we did not open them to check the integrity of the wiring inside.

We buttoned everything up and called it a day around 2:30 PM.  I won’t know if any of the work we did today fixed our speedometer problem until we depart Williston Crossings RV Resort in April.

 

2013/12/26 (R) Our Recent Travels

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We left Williston Crossings RV Resort in Williston, Florida at 10:15 AM and traveled to the Turner Agri Civic Center in Arcadia Florida for the Arcadia (Bus’in) Rally 2014.  Our route took us down US-27 to I-75 to FL-70 to US-17 and over to the rally venue, covering 200 miles in 3 hours and 45 minutes.  I-75 had a lot of traffic and a few construction zones, but US-27 and FL-70 we excellent roads with very few vehicles.  I have not been posting maps of our daily travels, so here is the route we have traveled starting on the 19th.  We have traveled about 1,300 miles in that time.

View Larger Map

We were met at the check in station by Bill and Brenda Phelan who now run the Arcadia Rally.  Linda took care of the paperwork while I introduced myself, indicating that I had been asked by the publisher of Bus Conversions Magazine to do an article on the rally.  We unhooked the car and were escorted to our back-in site.  We immediately recognized the bus parked behind us as belonging to Bill and Karen Gerrie.  They always travel with Karen’s sister Katherine and her husband Mike, and sure enough, they were here too!  By the time the rally starts on Sunday we expect there to be other converted bus people here that we know.

We were escorted to our site, backed in, straightened out, and leveled and then went through our usual arrival routine; Linda setting up the inside while I hooked up the electrical shoreline and checked the house battery state of charge and that the inverter/charger was working.  We then deployed the awnings.

While opening and securing the main patio awning the front rafter arm started to come off of the awning shaft.  Closer inspection revealed that there was supposed to be a retaining pin or bolt holding these two pieces together, but it was missing.  Yikes!  I looked down and there was a black bolt of approximately the right diameter and length on ground in front of me.  Was it possible that this had just fallen out?  I looked at the other end of the roller tube and there was the matching part, but with a Nylok nut on the end.  I went back to the other end and looked for the nut, but didn’t see it.  It probably fell off a long time ago, if it was ever there in the first place.  No one has worked on these awnings since they were installed by the Zip Dee Factory outside of Chicago, Illinois in October 2012.  It would have been very, very bad if these two parts had separated while we were traveling on the highway.

I managed to get the bolt back through the mating holes, but I did not have a Nylok nut of the correct size in my parts kit.  The Gerrie’s have a 1965 GMC bus that they converted.  Bill is a very knowledgeable and resourceful guy when it comes to buses, but he did not have an 8-32 Nylok nut either.  I did have some regular 8-32 nuts, however, so I double nutted the bolt and snugged it up nice and tight.  We added 8-32 Nylok nuts to our growing list of supplies we needed to buy and things we need to do.

With that chore out of the way, we pulled up the chairs and settled in for a chat.  I mentioned the Check Engine Light issue and erratic speedometer problem we’ve been having, and quick as a wink Bill had his ProLink/NexIQ engine diagnostic tool out, hooked up to our bus, and we were reading codes.  The DDEC II engine computer did not have any active codes set and only one inactive code.  The inactive code was for a fuel temperature sensor high voltage.  Joe Cannarozzi (our mobile mechanic) and I had replaced the fuel temperature sensor back in the spring but I never got around to hooking up my ProLink and clearing the old code.  That little oversight has caused me way too many anxious moments.  My bad.

Bill also had a special card for his diagnostic equipment that allowed us to look at the error codes from the ATEC transmission computer.  No codes were set, indicating that the vehicle speed sensor was sending a good signal at least as far as the transmission computer.  We assumed that was the case as the transmission was working great and the cruise control was working as it always has.  The erratic speedometer appears to be either a wiring problem between the computer and the dashboard or the speedometer gauge itself.  The easiest/cheapest thing to do would be to clean the connectors on both ends.  The next easiest thing would be to replace the speedometer and hope that’s the problem, but that will not be the least expensive solution if turns out not to be the gauge.

Although I had stopped worrying about the Check Engine Light, it was a great relief to know that there were no active error codes being generated by the engine or transmission computer.  One of the great things about rallies in general, and converted bus rallies in particular, is that many converted bus owners have done their own conversions and have a special sense of community about their machines.  They know their way around buses, travel with tools and parts, and are usually willing to help each other when there’s a problem.

With a potential awning disaster discovered and averted and the Check Engine Light issue resolve, we finally settled in to our chairs for a long, well-deserved, chat.  While we were talking four Sandhill Cranes walked by about 50 feet away.  These magnificent gray birds have a distinctive red cap on their heads, and can stand almost 4 feet tall.  Although they tend to spend summers much farther north in Michigan’s Upper Peninsula and Canada, we have them on our property in southern Michigan during the late spring to early winter.  We also saw kildeer, and several other birds we did not recognize.  On the drive down today we saw pelicans and egrets plus the usual raptors that can often be spotted along highways.

By 5:30 PM it was getting dark and mosquitoes started to appear so we wrapped up our conversation and headed inside for the night.  With all of the activity and socializing we had managed to skip lunch.  Rather than take an hour to prepare something, we had the chickpea salad Linda made the other day.  It’s one of our favorite cold dishes and reminds us of egg salad.

Linda turned on the TV and scanned for channels.  We are parked facing west with the front OTA TV antenna pointed slightly north of our nose.  That’s somewhat in the direction of Tampa St. Petersburg although they are actually northwest of our location.  The scanner found 60 digital stations, so she flipped through them to see what was there.  We had the PBS trio, a weather station, the usual commercial offerings, and lots of Spanish language stations.  Impressive really; if you look at a road atlas Arcadia is 40 miles east of I-75 and appears to be in the middle of huge swamp.

We could not find a usable Wi-Fi signal so we turned on our Verizon Mi-Fi device and got online.  If you need to be online while traveling, you need to have more than one way to get there.  (Technomadia has the definitive book on the subject for RVers.)  We checked e-mail and I worked on this post.  We took a few minutes to have vegan chocolate cake with fresh strawberries.  We finished up our online work and went to bed early.  Although the rally does not start until Sunday, I have to start acting like a reporter tomorrow so I can write a really good article on this event with lots of good photographs.

2013/12/21 (S) Winter Solstice

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Often referred to as “the shortest day of the year” the winter solstice is the exact same length as every other day of the year.  What’s special about it is that in the northern hemisphere it is the day with the least time from sunrise to sunset and the most time from sunset to sunrise.  From here to the Summer Solstice the minutes of daylight increase slightly each day.

As glad as we are to be headed south, there are always reasons to stay home.  Family tops the list, especially birthdays and holidays, but we took care of that with the cooperation of our families.  We have our friends and clubs, of course, but another reason would be the Winter Solstice Special Release Party at Schramm’s Mead in Ferndale.  Since we could not be in two places at once, we will just have to hope that Ken still has some Winter Solstice left when we get back.  🙂  If not, perhaps Ken will have a Vernal Equinox Special Release or a Summer Solstice Special Release.  Any excuse to buy Ken’s mead.

What we did instead was pull out of the Oh! Kentucky RV Park/Campground at 8:20 AM and drove 0.3 miles to get back on southbound I-75.  It was dry but overcast as we started out, but we were in and out of rain for most of the drive.  The rain was generally light, but we did encounter heavier rates from time-to-time.  We did not experience much fog, but we did have some areas with ground clouds.  We made it past Knoxville, Tennessee without the problems we had back in October.  This was the farthest south we have been with the coach, and the first time I have driven I-75 south of Knoxville.  We made a brief stop for fuel at the Pilot Travel Center in McDonald, Tennessee and continued south on I-75 into Georgia.  This the first time I have driven anything in Georgia and the first time we have had the coach there.  Even with the rain it was a relatively easy and uneventful drive, except for the continued, almost random, on/off of the Check Engine Light.  The coach ran well with good power and all of the gauges indicated normal operation, so we just pressed on.  When we get settled in Arcadia for the rally I will pull out the ProLink and read the codes.  That should draw a crowd and might even make for an interesting round-table discussion.

At 1:30 PM we took exit 111 and headed west 0.3 miles to the entrance of the Cartersville/Cassville-White KOA, This was our first time staying overnight in the Georgia in the motorhome.  Linda had called ahead when we were near Knoxville, Tennessee, so we knew the office would be closed from 11 AM to 3 PM.  The office manager left a map of the campground for us in the night registration station with our spot marked on it and the route to take through the campground to get there.  She even put an orange traffic cone at the entrance to our site to mark it as reserved; very thoughtful.  The temperature was in the low 60s when we arrived and rose to 69 during the evening.  Rain was forecast for the later evening and thunderstorms for the overnight.  As we have done since before we left, we kept an eye on the weather.

This is the second KOA we have stayed at in the last three months.  We tend to think of them as overpriced with lots of amenities that appeal to families with kids, but that we don’t use.  Both parks, however, have been very good places for us to stay, with:  convenient access; good gravel interior roads with sufficient width and turning radius for our rig; mature trees trimmed up high enough to not scratch our motorhome; pull through sites with 50 amp full hookups; and clean bathrooms with good showers.  The one in Natural Bridge, Virginia was full of kids, but it was a weekend near Halloween and we had fun giving away candy to the trick-or-treaters.  The current location appears to be no more than 40% of capacity, with no evidence of kids; definitely off-peak season.

As an update to yesterday’s post, I discovered that I was pushing the wrong button and that both windshield washer pumps do, in fact, work.  Duh.  L  The good news was that both windshield washer pumps work!  J  When we got to our destination I switched the output hoses back to their correct pumps so everything should work the way it’s supposed to tomorrow; except perhaps for those clogged orifices on the lower wiper arms.  It’s always something, it seems, and any RVer who is honest about it will admit that.  But they will also tell you that it’s part of the experience/lifestyle, and you either learn to take it stride and deal with it or you end up doing something else.

As a final technical note, now that I have started valving off additional circuits on the auxiliary air system, the pressure seems to be holding much longer and thus the compressor runs much less often.  It is now at least a two hour cycle and may be holding longer than that.  The new auxiliary air distribution/control panel that I built last year and installed this past spring has made it possible to do this.