Simplicity-SKO
Senior Member
This thread is to summarize my no crank issue and solution so it's easy to find when searched on. The original thread can be found here: https://www.skoolie.net/forums/f37/urgent-no-crank-bus-stuck-35159.html
While this issue involved my year 2000, Model 3000 International / Amtran, with a T444E and MT643, the issue is so generic, I chose to to post it in the main drivetrain forum.
PROBLEM: No Crank, No Warning Light, No wait Light
SOLUTION: A lead on a diode broke. Fix or replace diode lead or associated connector.
SUMMARY: After driving my bus off and on for three years, I drove it to charge up what I thought were bad batteries because it was not starting. After charging the batteries overnight, the bus started. I drove it for about 20 minutes, including on the freeway to really charge the batteries more. I parked it in front of my house in a residential neighborhood so I could clean my driveway from the engine / tranny fluids I spilled in changing fluids and filters. I haven't parked it in the street but maybe 10 times because the parking nazis. When I went to start it, no crank, no self test lights.
Pic attached of connector with diode, but in case skoolie.net eventually removes it, I'm trying to write so future readers can visualize the connector.
DETAILS:
The Ignition Relay Socket, IRS, has a wire that leads out to three wire socket. This socket has a total of three wires that are individually connected to the following:
a) IRS
b) wire bundle that feeds the rear electrical panel (this is the common wire)
c) the rear engine compartment ignition switch
Then there is a connector (that fits into the socket). It is shaped like a pyramid with one terminal on top of the other two terminals. The Terminal on top is the common from the wire bundle. One of the bottom terminals goes to the rear ignition switch and the other to the IRS.
There are two diodes. One diode connects from the back of the connector from the IRS terminal into the common, the other diode connects from the back of the ignition switch terminal to the common.
NOTE: We could not find this arrangement on the front ignition switch. There is nothing we could find about why these diodes are there. Diodes are used to keep electricity flowing in one direction. Since there are two ignition switches, this might be to keep the voltage from back-feeding between the front and rear ignition switches.
These diodes were exposed out the back of the connector. To protect them, they were covered by a plastic tubing. The tubing was yellowed and it was hard to see what was inside them, yet one tube had been worn through after years of probably vibrating around inside the nest of panel wires.
Upon investigation, by removing the plastic tubing, we found one of the diode leads broken. Not understanding why the diode was there, we were concerned about possibly wrecking something like the ECM if we hooked the broken leads together.
Unfortunately, my rear electrical panel shows 7 relays, but there are only 5 physical ones. We were not sure which were which, so at this time, we did not fully understand what was occurring. We proceeded to trace the relays using the number/letter combinations of the wires against the diagnostic manual schematics.
During this tracing, we inserted solid wire leads into the switch terminals of the ignition relay. When I "accidentally" knocked the two leads together, the engine cranked. It was a moment of pure joy and terror at the same time. Totally unexpected.
After tracing, identifying and, yes, labeling all the relays, we turned back to the diode connector. We simply twisted together the two remaining leads of the diode and connected it into it's socket.
KOEO, Boom, all my diagnostic lights came back on! Joy erupted! A quick bump of the key and they engine cranked.
LESSONS:
Documents: I was initially using the June, 1997 EGES 125 version of the diagnostic manual. ABBus sent me the December 1997 EGES 190 version. The 125 version was searchable on the computer, but the 190 version wasn't. Yet, the 190 version was more accurate in relation to my bus.
Troubleshooting: There was nothing that led us to a broken diode lead. It was simply a good friends years of experience in trouble shooting electrical issues that he noticed this worn plastic tubing.
We had to essentially take apart my rear electrical panel, remove all the tape that created the individual bundles and such so we could accurately trace and identify the wires. When we did that, we were able to find the ignition relay diode connector.
We did our best to follow the test procedures, yet the manuals are used for such a variety of vehicles, use different words and acronyms at times (like International uses the term ECM throughout their manuals, but labeled the ECM relay as CEC??), and our general lack of familiarization with the vehicle and systems really made it difficult.
We definitely know more now about my bus and how it operates! I've learned soooooo much.
Persistence, researching, reading, begging, etc...all are required. Oh, sleep, sleep helps.
PARTS:
While some parts are easily available, this particular diode connector is a unicorn. The diode is approximately the size of a cooked grain of rice and cylindrical. Identifying its values to simply replace the single diode is almost as hard as finding the damn thing in the first place. The joy of owning an old anything.
COMMUNITY:
The members of skoolie.net are awesome. Some had good problem solving advice, some were empathetic and encouraging. All are appreciated!
FRIENDSHIP:
What a blessing to have new and old friends try to help. My friend has spent many hours discussing my bus build, loaning me tools to make my job easier and been invaluable in helping design and build my operational aspect of my conversion. His love of diesel engines and skills cannot be understated or undervalued.
I hope this post helps someone resolve their no crank issue.
Cheers!
While this issue involved my year 2000, Model 3000 International / Amtran, with a T444E and MT643, the issue is so generic, I chose to to post it in the main drivetrain forum.
PROBLEM: No Crank, No Warning Light, No wait Light
SOLUTION: A lead on a diode broke. Fix or replace diode lead or associated connector.
SUMMARY: After driving my bus off and on for three years, I drove it to charge up what I thought were bad batteries because it was not starting. After charging the batteries overnight, the bus started. I drove it for about 20 minutes, including on the freeway to really charge the batteries more. I parked it in front of my house in a residential neighborhood so I could clean my driveway from the engine / tranny fluids I spilled in changing fluids and filters. I haven't parked it in the street but maybe 10 times because the parking nazis. When I went to start it, no crank, no self test lights.
Pic attached of connector with diode, but in case skoolie.net eventually removes it, I'm trying to write so future readers can visualize the connector.
DETAILS:
The Ignition Relay Socket, IRS, has a wire that leads out to three wire socket. This socket has a total of three wires that are individually connected to the following:
a) IRS
b) wire bundle that feeds the rear electrical panel (this is the common wire)
c) the rear engine compartment ignition switch
Then there is a connector (that fits into the socket). It is shaped like a pyramid with one terminal on top of the other two terminals. The Terminal on top is the common from the wire bundle. One of the bottom terminals goes to the rear ignition switch and the other to the IRS.
There are two diodes. One diode connects from the back of the connector from the IRS terminal into the common, the other diode connects from the back of the ignition switch terminal to the common.
NOTE: We could not find this arrangement on the front ignition switch. There is nothing we could find about why these diodes are there. Diodes are used to keep electricity flowing in one direction. Since there are two ignition switches, this might be to keep the voltage from back-feeding between the front and rear ignition switches.
These diodes were exposed out the back of the connector. To protect them, they were covered by a plastic tubing. The tubing was yellowed and it was hard to see what was inside them, yet one tube had been worn through after years of probably vibrating around inside the nest of panel wires.
Upon investigation, by removing the plastic tubing, we found one of the diode leads broken. Not understanding why the diode was there, we were concerned about possibly wrecking something like the ECM if we hooked the broken leads together.
Unfortunately, my rear electrical panel shows 7 relays, but there are only 5 physical ones. We were not sure which were which, so at this time, we did not fully understand what was occurring. We proceeded to trace the relays using the number/letter combinations of the wires against the diagnostic manual schematics.
During this tracing, we inserted solid wire leads into the switch terminals of the ignition relay. When I "accidentally" knocked the two leads together, the engine cranked. It was a moment of pure joy and terror at the same time. Totally unexpected.
After tracing, identifying and, yes, labeling all the relays, we turned back to the diode connector. We simply twisted together the two remaining leads of the diode and connected it into it's socket.
KOEO, Boom, all my diagnostic lights came back on! Joy erupted! A quick bump of the key and they engine cranked.
LESSONS:
Documents: I was initially using the June, 1997 EGES 125 version of the diagnostic manual. ABBus sent me the December 1997 EGES 190 version. The 125 version was searchable on the computer, but the 190 version wasn't. Yet, the 190 version was more accurate in relation to my bus.
Troubleshooting: There was nothing that led us to a broken diode lead. It was simply a good friends years of experience in trouble shooting electrical issues that he noticed this worn plastic tubing.
We had to essentially take apart my rear electrical panel, remove all the tape that created the individual bundles and such so we could accurately trace and identify the wires. When we did that, we were able to find the ignition relay diode connector.
We did our best to follow the test procedures, yet the manuals are used for such a variety of vehicles, use different words and acronyms at times (like International uses the term ECM throughout their manuals, but labeled the ECM relay as CEC??), and our general lack of familiarization with the vehicle and systems really made it difficult.
We definitely know more now about my bus and how it operates! I've learned soooooo much.
Persistence, researching, reading, begging, etc...all are required. Oh, sleep, sleep helps.
PARTS:
While some parts are easily available, this particular diode connector is a unicorn. The diode is approximately the size of a cooked grain of rice and cylindrical. Identifying its values to simply replace the single diode is almost as hard as finding the damn thing in the first place. The joy of owning an old anything.
COMMUNITY:
The members of skoolie.net are awesome. Some had good problem solving advice, some were empathetic and encouraging. All are appreciated!
FRIENDSHIP:
What a blessing to have new and old friends try to help. My friend has spent many hours discussing my bus build, loaning me tools to make my job easier and been invaluable in helping design and build my operational aspect of my conversion. His love of diesel engines and skills cannot be understated or undervalued.
I hope this post helps someone resolve their no crank issue.
Cheers!
