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Hi folks,

That is a nice looking Citicar you have there. Do you have the service
manual? An updated reprint of one was available from Assembled Products
(formerly Nu-Kar) at: I am not sure if the
still offer them or not. I scanned a number of the circuit diagrams and
posted them in the group file section at:


The speed control system on the Citicars is very archaic. It supplies power
to the motor in three steps, 18, 24 and 48 volts. To do this there are
three micro-switches triggered by a cam connected to the "gas" pedal.

1. Turning the "ignition" switch to "on" and releasing the parking brake
switches the center short relay in the control group from series to parallel
(48 to 24 volts) and activates the 12 volt accessories.

2. Step one on the cam causes the tall forward/reverse contactor closes
(either up or down depending on the direction of travel selected) and 18
volts is supplied to the motor. In this setting the pack is operating as
two parallel groups of four batteries supplying 24 volts, which is then
reduced to about 18 volts by a large nichrome ribbon resistor, (the large
spring like device near the right rear wheel.) These is the least
efficient setting and should only be used for a short time. The purpose of
this setting is to protect the motor from surge currents while starting out
from a stop.

3. Step two on the cam triggers the small enclosed relay (it looks like a
starter solenoid) which by-passes the nichrome resistor. This kicks the
voltage up to 24 volts. This is the speed range where maximum range can be
achieved though the speed is pretty low, probably no more than 25 mph.

4. Step three on the cam (floored) switches the center relay from parallel
back to series and supplies 48 volts to the motor. This is when maximum
speed can be achieved, on my car that was about 38 mph on level ground.

The control system and the brakes are the two major problems with the
Citicars. I ran mine for years using the original contactor system and
seemed to have failures of one kind or another on a weekly basis. I finally
upgraded it to a modern Curtis electronic controller with the system
operating at 48 volts all the time. This did nothing to increase the speed
but the reliability and drive ability was outstanding. I can't imaging
running one of these cars without it now.

I noticed your car has the front disc brakes. As your instructor has
probably already noticed, the front brake calipers are rather poorly
designed. Make sure nobody tries to hone them out with a conventional brake
caliper hone. They are very soft aluminum and will not survive such
treatment. Any cleaning should be done with very fine sandpaper and
solvent. There was a retrofit of four small springs on two metal brackets
to help get the pistons to return properly. You should find it in the
manual under the brake section. If you don't let me know and I will scan it
in.

On my car I tried many solutions to the brakes and eventually upgraded to
the front drum brakes from a Comutacar. If you can keep the front disc
brakes working I would suggest you stick with those.

Adding solar panels or regenerative braking is not going to have a
significant effect on your range.

Regen on EVs is primarily to reduce the load on the brake system. Only the
energy used to accelerate the vehicle is available for recovery, any energy
used to maintain cruising speed has been used to overcome drag and is gone.
In hilly areas regen can capture some energy descending hills, but you only
recover a fraction of the power used to climb the hill in the first place.
Regen systems for DC drive vehicles are expensive and tend to have great
potential for causing problems.

I don't believe adding solar panels to a Citicar would help too much. The
array would have to be very small, probably not much more than 250 watts,
and when you consider the on-board 1800 watt charger takes about 8 hours to
recharge the pack completely you can see that a solar array would take over
7 times as long. When you also add in the question of cost that solar array
becomes even less appealing.

Extending the range on a Citicar is probably not really all that important.
Due to the limitations of its top speed and interior comfort the 40 to 50
miles it can manage are usually quite sufficient. It is really a little
round town runabout and that it can do very well.

You have a couple of neat little vehicles there and they can teach you quite
a bit. Please keep us all informed of you progress and feel free to share
any problems you encounter.

Thanks,

Mike Chancey,
'88 Civic EV
Kansas City, Missouri
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