Truck #2

If you have not noticed or heard, I’ve opened the US store for USE owners so they can get repairs and parts to keep their vehicles running. There are links on this blog to take you there. Enjoy!

Now the air conditioning is wired so that it can only come on after the truck is
fully booted. This also stops the truck from faulting if the AC was left on when
the truck is booting up. The schematic has been updated to reflect the changes.

I’ll test the temperature drop of the AC system during the next time it gets hot

After checking the AC relays, one was turning on the AC itself, the other was
suppose to be turning on the fans. The fan relay tested ok but it’s output was
not going anywhere. There was a white wire down inside of a wiring harness that
had been cut. I never did find the other end. But as it turns out it was the
output from the fan relay.

So I wired it to the fan harness directly. The fans now come on the instant the
AC is turned on. This allows the condenser to do it’s job and made the AC work
as it should.

It’s not a surprise that someone cut this wire. With the fans on you cannot hear
anything else. But even worse, when the AC is on when the ignition is turned on,
the truck faults. With or without the fans running the truck faults with the AC
turned on at ignition time.

The temperature knob does still change the rpm and thus the output of the AC
system. I still need to scope the outputs of the Sanden box to see if a system
can be installed without it. A DVM showed there was a variation in voltage that
followed the position of the temperature knob.

This truck has an old processor in it and the dc-dc only puts out about 13.5
volts under load. I’ve seen this combo in the past not allow a vehicle to boot
up, only because the load on the 12v aux battery is so high that the minimum
voltage for bootup is not achieved. I’ll dig into it more.

The AC vent temps got down to 32.8F sitting in the garage where the ambient temp
is only about 65F. I didn’t think the thermistor would allow it go down that
low. Usually AC systems are rated in terms of the delta in temperature that can
create. When it warms up I’ll take the truck outside and see how well it does in
real heat.

Yesterday the #2 truck got most of the body clayed using the Groit’s Garage system. Eddie clayed, polished, and sealed my #1 truck using this same system and it came out fantastic. So now I have a much better clue as to how much work it is. I still need to get the body lines clayed, but I just ran out of steam. This was exhausting work. The paint already looks far better and it’s not even polished or sealed yet.

I’ve tried to use 3M General Purpose Cleaner for removing marks on the paint. It’s helped, but not as much as using Goof Off in a spray can. Good Off is stronger solvent but does not damage the paint.

I’ve also purchased a chip filling kit to help fill in the chips this truck has. The paint code is 5111. The name of this shade of white changes depending on the vendor. So I won’t report it here.

I spent a lot of time watching Youtube videos showing how to fill chips. Some are fast and easy. But most are geared toward average, or less, results. So I may have to invent my own process using steps from the various vendors that I watched. Deep chips need to be filled with a bit of primer if the steel was exposed. Some may even require some fine filler due to the dept of the chip.

I put an ad on Craigslist for the rear bumper, class 3 trailer hitch, and a bed mounted tool box. These are the parts I took off of both USE trucks to they could have perfectly functioning tilt beds. I wanted only $40 for all 3. But the only fellow that showed interest, did not need the other stuff. So I cut the price to $20 and he took all of it. It was all stored in the wagon. This stuff took up all of the room in the wagon. Now it’s nice and cleared out. Still there is a USE motor back there. I was just glad to get rid of it all.

Last night I finally got the blower to stop running when the selector switch was in the off position. It turns out that USE wired it in such a way that it grabbed power from an always on source. Although it appeared that I also added to the issue. The blower was tied to a 3 amp circuit for power. So when I turned the blower up to high, it popped the 3 amp fuse. Now it’s rewired straight to the heater/ac fuse and gets all the juice it needs. The 3 amp circuit is now independent and works fine. All of this also made me update my heater/ac schematic yet again. I have not looked at an air conditioned truck before so I am not sure if my wiring will match. I made this system work the way that is the most useful and makes the most sense. This truck was an early version and their ac wiring was not tested enough to find any bugs. The big thing is that the heater and ac never worked from day one according to the original owner. So I think now the system is wired correctly. Buying the factory S10 manuals used from Ebay made a huge difference in diagnosing the electrical and vacuum issues with the #2 truck!

I also bumped the regen in first gear to the maximum. The first time I tried it the truck shuddered like mad, but without faulting. The pack voltage jumped from about 330v to 380v. There is a limit to the voltage and I exceeded it. This really points out how high the pack impedance really is. This pack is shot.

When the dash gets taken apart the orange heater switch has to get pulled out. So the small panel that it is mounted to clips into the dash bezel. One of the molded in tabs snapped off. I used my standard repair of CA (CyanoAcrylate) and Kelvar strands to fix it. It may make the tabs too stiff which would require them to be shaved down a bit so they can be installed/removed easily.

I also added 2 12v batteries to the #2 truck’s pack. The pack is showing such low voltage output as the seasonal temperatures get down into the 30’s. Then the charge curve had to be increase up to 400v since there are now 27 batteries in the pack. That should get the truck around the block over the next few months. I did notice that the 592AE processor would not accept a full download of the .set file. I think it might be because the file was for a 5B5AA processor. The only real difference is in the checksums being different. So I went through manually and changed the several settings to match the nicad settings so the truck will charge higher and run on a lower pack voltage if needed.

I have this other circuit design that looks like it could be modified
and adapted to actually giving real temperature control to the USE heaters.
Since the heater element runs on pack voltage this would be a high voltage
control with a pot on the dash that changes the temperature. The pot
would be opto isolated for safety. It would be just a single board
that connects after the heater relay to pack voltage, and uses high
voltage fets for controlling the power to the heater element.
Depending on the space available, it could mount in the heater box

Interestingly the pressure sensor was not wired in even though it was
in the factory schematic. It’s easy to see where is could be added
into the circuit, but clearly had never been wired in when the AC was
installed. You almost cannot see the pressure sensor. It is wired in
right under the Dolphin and on top of the AC compressor. No mating
connector in sight. It was so hard to reach I could not test it’s
continuity with my meter. The spare compressor I have shows infinite
resistance at no pressure. So I am assuming that my charged system
would show close to zero ohms. This means the compressor could be run
without pressure, at least on this truck.

Slick system. As the temperature knob is rotated warmer, the
compressor slows down. It pulls around 5 amps from the pack at max
output in about 75 degree air. So it’s not well loaded for a max amp
test. That will have to wait until summer.

This truck is becoming a keeper.

Yes!!!!! The air conditioning is fixed!!! What a bunch of work that was!! The story goes like this. The factory had a learning curve as they built their first few vehicles. The #2 truck was an early version. So the wiring for the AC and heater had been set up in a way that was very untested. Instead of a switch to turn on two relays, they used one of the pots that is part of the temperature control on the dash. As the pot is rotated, it slowly brings the voltage up to the coils of the two relays. The problem is that the relays don’t come on at the same time!! So the heating element would turn on long before the water pump would and smoke the heating element. That’s why this truck never had a functional heater. The air conditioning had a bad crimp at the AC controller plus the ground for the AC controller was corroded badly. I had to clean the pins and sockets up for each of the 12 connections. That’s all it took!

I also added the lighted dash switch that most trucks have to turn on the heater. Now the AC and the heater can be run completely independent of each other, or at the same time. Nice!!

The wiring to the AC compressor and controller can reach the top of the Dolphin. This will allow me to test my spare AC parts.

What really made this debug work well, was spending a week making a schematic from crummy notes that had been faxed from the factory 12 years ago. It was a lot of work. But it made the debug of the AC system far better. Now I have a massive 18″ x 24″ drawing of the entire AC and heating system. This never existed before! I’d like to add AC to the #1 truck now that I have a schematic, parts, and wiring.

The only odd item left to repair is the heater/AC blower. It’s always on. Even when the selector knob is off, the blower runs. It’s speed can even be adjusted from the fan switch. I didn’t see any rigged wiring. But I suspect the wiring was modified somewhere and it needs to get fixed.

The last couple of days I worked hard on getting a schematic for USE air conditioning finished. I am hoping to get the AC in the #2 truck running. It’s fully charged with freon but won’t turn on. So far I found one broken wire at the Sanden temp control unit. I jumpered it but it still won’t run. The time spent today did help get the schematic more complete. I even plugged in a spare system to the truck’s AC wiring but it still won’t run. I hope to figure this system out by the end of the weekend.

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