Modified van misfires |
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Question: I have a 2007 Toyota Sienna that has been modified to include a dropped floor, fold-down access ramp, hand controls and driver and passenger transfer seats. I have multiple sclerosis and use a scooter full-time.

My van has a baffling electrical issue that two different van conversion teams have been unable to isolate or fix. Both have confirmed the battery is strong and does not need to be replaced. The problem is inconsistent and intermittent, and of two weeks duration, so far. The battery has been dead and required a jump twice. On other occasions the ramp, transfer seats and ignition have been slow, suggesting a decrease in electrical power, but the van could be started. Today, I was able to start the van, but I could not get the ramp to retract. At the same time, none of the electrical features of the van would operate. Not the door locks, windows, door opener or closers, regardless of whether I tried the interior car switches or either of two key fobs. All this happened while the car was running. I tried all of these features again after the car was running for half an hour and none worked. A “car-smart” friend helped me, and he was also baffled. We gave up and turned the car off. Twenty minutes later the ramp operated like nothing was ever wrong. The window and door locks operate normally. I think my van needs an exorcist. Please help.

Answer: Problems like these are really tough to resolve as the commingling of the two manufacturers’ electrical circuits and systems leaves many uncertainties for the technicians performing the diagnosis. Can full documentation of the specific mobility modifications (wiring diagrams, component locations, installation instructions) be obtained? I’d start by checking how the Sienna’s door locks, door controls and windows may be involved with the added mobility equipment.

One hunch is a part of the mobility equipment, perhaps the ramp, may have a loose or corroded electrical connection in its circuitry, intermittently affecting operation. Perhaps the ramp attempts to extend or retract, but can’t reach the limit switch destination, and a trickle of power remains continually applied to the actuator, draining the Sienna battery. It sounds like you were close to a no-start. Careful observation as you depart the van during future trips may provide clues, such a protruding ramp or odd noises. Checking for symptoms such as illuminated courtesy lights or other unnoticed oddities, as well as what does work correctly, may assist diagnosis.

As a GM tech, I had headaches with van conversions, motor homes, ambulances and police cars that mixed manufacturer systems. Your Sienna is far more complex making this a hair puller.

As difficult as this may be, the Mobility Works folks will need to keep the van for as long as it takes, repeatedly operating all functions under similar circumstances to yours until the fault rears its head. A voltage drop test of the mobility circuits power and grounds, when they’re working satisfactorily may provide a clue where to look.

Brad Bergholdt is an automotive technology instructor at Evergreen Valley College in San Jose, Calif.

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