Throttle problems with '96 DS w/ potentiometer

ejmetz

Hi All - noob here...

I have a 1996 48V DS non-regen, series 3.1 motor, Curtis 1204-410 controller, with a potentiometer throttle. The issue is that it will not reach top speed.

I've disassembled, cleaned and adjusted the throttle pot, replaced the 3-wire connector, and measured the output resistance on the connector. All seems good.

I've done some searching, and basically found that these carts are horrible with these types of issues, but maybe you can give me some guidance. I'm pretty good with electronics, but this one has me stumped.

The Curtis manual is very clear about the throttle input being between 0 and 5k ohms - 0-300 for off/rest and 4.6k to 7k ohms for full throttle. They show a simple 2-wire potentiometer connection between the controller terminals 2 and 3.

The DS wiring diagram is a little more complex. There are 3 wires on the pot, one (purple) which connects to B- on the controller, one (black) which connects to terminal 2 through the speed limiting f/r microswitch, and one (yellow) which connects directly to terminal 3.

Question 1: Why is the B- connection to the pot there? Is this really necessary?

Question 2: The speed limiting resistor seems to be in SERIES with the potentiometer, not in parallel. Wouldn't this give you a range from 5k to 10k at the throttle input to the controller? How the heck does this work?

Question 3: What would happen if I just disconnected the B- line to the pot, and wired the pot the same way as Curtis shows in their manual, using a PARALLEL 5k for the speed limiter?

Question 4: Why is this so danged complicated?!?!?

Any guidance you all can provide would be greatly appreciated!!

Attached Images

	Curtis Manual Pot.JPG (15.0 KB, 16 views)
	CC 96 DS Throttle dwg.JPG (29.6 KB, 17 views)
	Curtis Manual Pot speed limit.JPG (27.8 KB, 13 views)

BGW

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ejmetz

BTW - I know I should probably update to the MCOR, but I don't want to spend the $280 if I don't have to!!

shadowman

what speed are you reaching? if your getting 12 mph your there................all the technical stuff you just [posted gave me a headache thanks................lol.................

ejmetz

Sorry about the tech details - it's kind of what I do for a living...

I'm not reaching 12 - probably closer to 9 on the flat. I need to clock it, but I know for sure that I am not keeping up with other stock carts of my vintage.

Heck - some friends had a 1993 CC DS 36V rental over the weekend that looked like it had fallen off the back of a truck, and it still beat the pants off me!!

sonicj

5k-0 is what the curtis wants to see. not sure why your pot is wired as a divider.... resistor is safe to remove. following curtis' schematics is safe. i don't think your potbox stock.

id just jack up the rear end and experiment.
-sj

ejmetz

That's what I will do. The ClubCar system looks overly complicated the way it is designed compared to Curtis' suggestion. I have to assume there was a reason for it....... or maybe not!

shadowman

maybe because it was overly complicated is why they only used it for a few years..................................

cheapjeep2

Why not spend just under a $100.00 and put in a PB-6 Pot box and your problems are solved, just have to rig up the mounting and linkage but can be easily done for WAY cheaper than the MCOR and way more reliable.

http://www.evdrives.com/throttles.html

ejmetz

I thought about that, and may ultimately do this. However, last night I hooked the existing pot directly to terminals 2 & 3, and got no output at all. Maybe the connection to B- is required for some reason?

cheapjeep2

all throttle inputs the ClubCars are three wire. I have the manual for a 1995 in XPS format. I'll email it to you.