Need electrical help. Any Chevrolet service techs here?

[tuscarora dave]

Hi all.

A little about what I'm working on.

I'm currently doing a wheelchair van conversion on a 2014 Chevy Express Explorer Limited SE conversion van. My client brought me the van with 350 miles on it and asked me to gut the entire back of the van and turn it into a wheelchair van. The job is just about complete now and I'm working on wiring up the module for the wheelchair docking station. I won't bore you with all the details on the docking station, but I'll mention a few things to describe what it is and how it generally works.

This docking station or EZ-Lock as it's generally referred to in the industry works essentially like a door latch would work except that it's bolted flat to the floor and electronically controlled. The wheelchair is outfitted with a plate on the bottom of the chair that has a large diameter bolt (or pin) threaded into it that locks into the latch of the docking station as the wheelchair occupant drives the wheelchair into the docking station. The pin self aligns to a degree and then snaps the latch shut on the pin as the wheelchair is driven to the forward most position into the EZ-Lock and the latch snaps shut around the pin and the chair is locked in place. There is a constant hot 12 volt connection, a ground, three different triggering keypad devices to unlock the wheelchair when the time is right and to turn off any alarms that might sound.

In addition to these other electrical connections, there is a lead that connects to "ignition". This circuit goes to a safety feature that prevents the wheelchair from being unlocked from the docking station by opening a normally closed relay, essentially "locking out" or "opening" the control circuits while the vehicle's key is switched to the "on" or the "run" position, thus making unintentional unlocking of the chair impossible while driving down the road, which could certainly be disastrous.

I did find an unoccupied 4 pin connector under the kick panel to the left of the parking brake that had a source of ignition switched 12 volts and I soldered my ignition wire into that but unfortunately, when the rear climate control fans are turned on, the current going to the fans draws down the voltage from that pin causing the safety feature not to work. What I need is a dedicated source of switched ignition voltage, and preferably under or near the driver's pedal assembly. I don't want to pull this switched power from anywhere on the dash where dis-assembly will be required to carry out routine repairs or general maintenance, such as around or above the dog box cover.

Do any of you Chevy Express owners / mechanics know where I can tap into ignition voltage from somewhere around, behind or above the driver's pedal assembly? I'm not certain that there's not an unoccupied spare ignition fuse somewhere where I could pull this power from, perhaps in the fuse panel under the hood? I can't use another circuit that pulls a heavy electrical load, that would intermittently rob current from my EZ-Lock ignition circuit.

Any and all thoughts and or comments are welcome. Thanks in advance. TD

 

[swanicyouth]

Dave, I did a bit of looking around and it seems that vehicle has two fuse boxes - one under the hood and one under the driver's seat (assuming I'm looking at the correct vehicle).

Here is a representative schematic of a 2012 under seat fuse box:

Whenever I do something like this, I usually look for an empty fuse that is hot when the ignition is turned on. The way I figure it out is just to use a test light in the various fuse locations - checking each with the key on and off.

I usually tap right into the power side of the fuse box (assuming slot open and no fuse) with a blade connector filed down a bit. Then I'll use an inline fuse on the wire right after the connection to the fuse box. I'll usually secure it to something with a wire tie, so it doesn't wiggle around. This way, you don't have to hack any wires up and it's 100% reversible to factory.

Good luck.

***As an aside, I remember working on Econo Line conversion vans back in the day.... A typical RO would look like this:

1. Customer states TV doesn't get good reception on channel 3.

2. Customer states drapes are crooked on passenger side window.

4. Customer states wood trim paneling is loose over refrigerator area.

5. Customer states carpeting is "bunching up" around door.

When we saw a ticket like that, the service desk would turn into a ghost town.... Word would spread around the shop there was a conversion van up there and nobody wanted to go anywhere near the service desk for fear of getting that job.

 

[dcjredline]

Hey Dave, You have eliminated the best place to get a switched 12v source so I have no ideas. As an old MECP certified installer I would direct you to the ignition switch but understand your need for serviceability.

 

[Setec Astronomy]

Word would spread around the shop there was a conversion van up there and nobody wanted to go anywhere near the service desk for fear of getting that job.

Yeah, I remember one (I think it was a Dodge) that the wipers wouldn't work, but if they turned them on, then opened the driver door, the wipers would start working and work for about 30 seconds after the door was closed.

The same guy always worked on the conversion vans, he said that they had put a TV or something on the wiper circuit and overloaded it, so they had scotchlocked the wipers into--you guessed it, the dome light circuit. And yes, he hated getting the conversion vans, because it was always something like that.

 

[Turbo5upra]

Is the voltage drop is significant enough to not allow you to pull in an additional relay with the wire you've already found?

 

[tuscarora dave]

Thanks for the replies guys. I must have been blind because there was a 10 gauge auxiliary connector sticking out of the main harness coming in exactly where i'd have preferred it to be. Connected to it with an inline fuse holder and all is good.

I'll be posting photos of this conversion before long as soon as it's finished up and washed. Got quite a few in process photos so far.