Swapping a T1 controller

eliminating plug braking and regen will also help a controller run cooler. 35 psi in tires to lower rolling resistance helps a lot. I wouldn’t waste the money on T1 repair. Do the T2 upgrade(R4F and I think FSIP have kits) or the ac conversion.

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Note: I accidently tapped POST before I was done with this. Some of this may be an incomplete thought and will be corrected.

Curious- Searching the archives I found the point in Dec 2019 where you imade this statement -

I had overheating problem as well, I have a 2002 4 seat, that I have reprogrammed and bigger motor. I created a mount and added 3 mini fans that blow at my controller. I have not had any issue since, however it hasn’t been that hot outside but seems to work for me.

What has changed? Driving habits? Finally get warmer weather? Did you add the battery after this?

Open Discussion:
I don’t understand the overheat while going slow(in a parade) issue. Going slow doesn’t sound like a high/max current thing to me. Unless it is a bunch of high current blips then regen/braking that ends up heat soaking the FETs? From a data logging perspective throttle input would look like a jagged sawtooth, or much like our Malibu earthquake we had the other day.

A while back we had another guy that was using a Gem for his orchard spraying (going slow) and he also had controller overheat issue. Many suggestions were offered, but It is unclear if his problem was actually solved since he never cam back with a follow-up report.

It makes me wonder what is making the controller work so hard when going slow?

It sounds like more of a duty cycle thing.
#2 looks normal. I need to play with this one more to see if it does what I’m thinking.

I am confused at what you currently have set for #3?
Was 1.8, then you set it for 11, then 5? That looks way too low. This number is not in seconds, it is 0.086 seconds per set unit. A setting of 5 means the controller takes .43 seconds to react to the change in throttle input.

Your pedal must be really twitchy? Bump it up to 30 (2.6 sec), maybe even 40 as a radical test. If it seems to solve the heat issue then sneak it back down a bit. The car will feel a bit less responsive, but running a lithium pack you probably won’t know it.
Are you still running the Bolt 20s?

Plug Braking
I agree with the others. You have values in 5 and 16. You should dial those down. Bring 5 and 16 to 0. You might not be hitting on it, but just to make sure.


I was tinkering on the cart this time of the year when my work is slow. so come june and july when the weather here in Ohio is very warm it starts over heating.

I believe I moved the throttle down to 11 because when i out the lithium packs in the cart my front en tires where spinning on take off. I will adjust that back to 30 or 40 and see what happens, again it has been a long time since I have messed with the settings.

My kids are now 14 and 16 and the interest of the Gem car has going way down hill so we don’t use it much and when we do we get frustrated it over heats

I have Talked to FSIP and they quoted me $1149 for a T2 and a conversion cord from T1 to T2. that is a bit high for my taste. does anyone out there have a t2 they are trying to sell or sitting on?

Yep- I agree. $1149 is robbery. For a T2. Did they say if it was new? (ya right).

Have you tried tweaking some of the numbers in programming yet?

I might have an old T1 here that I can rob a temp sensor out of. Maybe yours is lying to you? (setting off way early) It might be fun to actually put a thermocouple on it and see what it is actually doing.

It’s so cold her in ohio to do testing that the test would not come out accurate. I am just going off of what has happen the last two years running it in the summer and knowing when I got the error code the controller was too hot and to wait 10 mins and it would be good to go.

From what The guy said when I called FSIP a t2 should do the job. But in the end he doesn’t know what we do to these carts.

It anyone knows of a T2 let me know.