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Discussion Starter · #1 ·
Hi. I purchased a Miles Etruck from a scrap yard. They allowed me to take as many spare parts as I wanted from the other vehicles. It comes with a Curtis 1238 controller. Was working fine but suddenly reduced to 5mph forward, still does 10mph reverse. Max forward was 25mph. I tried 5 controllers and two motors. Same result. Thanks for any help.
123481
 

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The next suspect... Check the output of the throttle.
 

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Anything else that you have swapped?
 

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Does it have some kind of speed profile / eco mode switch ? I've seen this in HPEVs Curtis programming - their eco limits only worked in forward direction, reverse was unrestricted.
 

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My next suggestion would be to watch the battery output as you try to accelerate. You have have a dead cell.
 

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Discussion Starter · #8 ·
Does it have some kind of speed profile / eco mode switch ? I've seen this in HPEVs Curtis programming - their eco limits only worked in forward direction, reverse was unrestricted.
Nothing like an eco mode.
 

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If there is nothing obvious, you may want to rent a Curtis programmer to look into the controller inputs. It must be sensing something and restraints the output because of that. Jack up the machine, plug in the programmer, give it full throttle and see if if the throttle demand goes up to 100%.
 

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Discussion Starter · #10 ·
My next suggestion would be to watch the battery output as you try to accelerate. You have have a dead cell.
I’ll try that. The weird thing is that if I drive reverse and switch to forward without braking, it has sudden torque until it exceeds 5 mph. Then it drops power again
 

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It may have a turtle mode if it thinks there is not enough juice to provide full throttle.

Ed
 

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Discussion Starter · #13 ·
It may have a turtle mode if it thinks there is not enough juice to provide full throttle.

Ed
Hey Ed. Do you think the Duracell batteries I put in it are no good? They are new at 750 cca. Thank you guys for all the help, I really appreciate it.
 

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It would be helpful if you list all of this at the beginning of your post.
 

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Hi. I purchased a Miles Etruck from a scrap yard. They allowed me to take as many spare parts as I wanted from the other vehicles. It comes with a Curtis 1238 controller. Was working fine but suddenly reduced to 5mph forward, still does 10mph reverse. Max forward was 25mph. I tried 5 controllers and two motors. Same result. Thanks for any help.
View attachment 123481
What is the voltage of the system that is in this vehicle?
I’ve swapped all parts except the ct on the positive battery lead. Another thing I noticed is that the battery % gauge fluctuates a lot
Why haven't you tried swapping" the batteries yet?
IMO, that fluxuating "battery gauge" is telling you, that something is not right
...& that's where ya wanna do some more investigation/testing

I designed & built a go kart, specifically to "pop wheelies"
...but, I first tried it with a used batt pack
...& it didn't perform as expected

Then, I installed a new batt pack
...& BOOM! "it was on" :cool:
 

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Discussion Starter · #16 ·
As you know, batteries aren’t cheap. I’m trying to rule out what I can before dumping another $1500 into it.
 

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They are new at 750 cca. Thank you guys for all the help, I really appreciate it.
:( you need to attempt to exchange those batteries for the proper type

what model battery are they?

Should be a deep cycle for golf carts or an AGM Deepcycle

True Deepcycle batteries never have a CCA rating

Next your problem is quite common on those vehicles, sadly trouble shooting can be problematic because there are a dozen possible causes, usually there are bad grounds and corrosion along the steering column, throttle and dash

Even the deutch connectors can be problematic
 

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I had a similar issue on my EV conversion with the Curtis 1238 controller.
here is my post: Troubleshooting my first EV - Ford Ranger conversion

It turned out to be the throttle. The throttle wiper voltage maxed out at 2V with the pedal all the way down, but the controller was expecting around 5V for full throttle. The nice thing is that all I had to do was change the range in the controller settings to tell it full throttle is 2V. I did the troubleshooting with a rented handheld Curtis tool but eventually found the Curtis PC software and bought the PC adapter off ebay.
 

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Hi. I purchased a Miles Etruck from a scrap yard. They allowed me to take as many spare parts as I wanted from the other vehicles. It comes with a Curtis 1238 controller. Was working fine but suddenly reduced to 5mph forward, still does 10mph reverse. Max forward was 25mph. I tried 5 controllers and two motors. Same result. Thanks for any help.
View attachment 123481
Hi There, I have two of these trucks and I unplugged the BMS and took the CT off the main battery lead. I put in Lithium batteries so used a different BMS, now the one on the dash always goes to 100%, and I don;t get locked into turtle mode because of a false state of charge....
 

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Discussion Starter · #20 ·
Hi There, I have two of these trucks and I unplugged the BMS and took the CT off the main battery lead. I put in Lithium batteries so used a different BMS, now the one on the dash always goes to 100%, and I don;t get locked into turtle mode because of a false state of charge....
Good morning and thank you. I was leaning toward that. I don’t have a scan tool and certainly don’t want to buy one at the price that they sell them. Could I take the CT entirely out of the loop and replace it with a jumper? Then the question would be what voltage it is sending to the electric drive
 
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