TA Electrical FAQ
- What is the truth about the malfunctioning CDI unit issue?
- What I can do to protect the two CDI units (TA prior to 1996) from being damaged?
- How to repair the CDI?
- I have an old (e.g. 1988) TA where one or both CDI are faulty. Could I install one from another model?
- ...and what is a CDI, anyway?
- I want to install an electrical accessory, but I am not sure if there is enough power from the alternator.
- What is the recommended capacity / configuration for a new TA battery?
- I see that Yuasa YB-12-AA battery is cheaper than Yuasa YB-12-AB (the model suggested for the TA). What is the difference?
- Is it safe to jumpstart the TA?
- How to adjust the headlight beam?
- But I don't have the special aim (lens and special screen) for verifying the correct headlight beam adjustment!
- How to replace the headlight bulb?
- There are water drops inside of the turning light compartment (usually the right front one)!
- I saw a switch on the clutch control lever. Which is its purpose?
- How much long I could leave the bike unattended without permanently degrading battery's performance?
- I suspect there is a current leakage when the ignition key is in off position. How to measure it?
- How do I tell a battery has reached the end of it's life?
- Why a commercial cheap charger overheats the battery? How do I make a simple safe charger using "off the self" parts?
- When trying to start the engine, starter is rotating without being engaged to the motor.
- When I try to start the engine, I see that the main fuse is blown. I replace it and the bike runs normal. Next day, same thing happens.
- I was riding late last night and (again) noticed that the outer edges of my tacho and speedo are much brighter than the inside (which is
very dimly lit). Also, the temp gauge is barely visible (lit more on the bottom).
- When I use a turning light, the front flashes very quickly while the back one not at all.
- When I activate a turning light, it exhibits a few sec delay before starting to flash.
- CDI seems to be malfunctioning (tachometer indication is wrong, rear cylinder doesn't operate or operates intermittently) but swapping the CDI units
doesn't reverse the problem.
- Recently, I need to fill in battery fluid at shorter intervals than before.
1.
Actually, the malfunctioning CDI is the only serious issue of any TA version, over the years 1989-1995 (1987-1988 models had
additional "immature" problems). They are fitted with two CDI units. One of them (responsible for the rear cylinder) is foolishly
located very near the lower side of the seat. When a rider sits on the seat, the latter stresses the whole area of the CDI around the
connector. After a few years of operation, connector solder joints inside the unit break and the corresponding cylinder operates
intermittently or not at all. Loss of power is prominent. If the speedometer is connected to the malfunctioning unit, it exhibits abnormal
operation or it doesn't operate at all. Thus, a quick way to identify if the fault lies on a CDI is to swap the units. If speedometer
operation changes after swapping, one of the CDIs is problematic. If you don't see any change, check the corresponding
plug on the frame (see question 24).
From year 1996, there is a single CDI unit located adequately away from the seat and the problem has been completely eliminated.
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2.
I saw the Greek HONDA agent sells a modified CDI holder that takes the second
unit away from the seat and it is a quite effective solution for preventing a
CDI from malfunctioning. Perhaps it is an official HONDA replacement. Here's
a good alternative from Christos Zervos:
"The adaptor (plastic holder) costs (in Greece) about USD15. I bought it
but I didn't installed it because there was not enough room under the seat due to the fact that I had also installed there a SPYBALL alarm unit.
So, I did something else to protect the CDI units from damage. I took out
the existing CDI plastic holder and I laid down the 2 CDI units (one beside the other) flat on the rear fender with the connectors facing down and
front. I also covered them with a layer of foam plastic underneath and on top of them (to protect them from vibrations). In that way they are
firmly seated without protruding to be damaged by the seat. I did that since 1 year ago and I had no problem since
then."
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3.
In order to repair a CDI (see previous question), you need to open the
unit, re-solder the broken joints using a heavy solder iron and re-insulate this
part in order to prevent moisture from causing leakages (there are relatively
high voltages on a few pins). Also take a look on Deti's
site.
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4. If
an exact replacement of a damaged CDI is not available, you may try one from
another model. Keep in mind that, even if the connections are compatible and the
engine seems to operate normally, a different "ignition mapping" may
exist. Therefore you must test the bike in all the useful revolution range.
Additionally, the speedometer may not display the correct RPM indication. Here's
the experience of Andy Smith on his 1988 TA. He installed two 1996 CDI units:
"It has come to the conclusion that not only do the CDI units of off a 1996 model
work but also off a HONDA Dominator. The only problem is that the Dominator does
not support the tachometer feature but if you can live without tacho you might
be all right ... The CDI units are working ok at the moment , I
don't think that they will give me any problems . But who can be sure! The
ignition mapping will probably be different to the older units due to the new
exhaust emissions laws in various countries. But I have noticed a slight change
in the actual performance of the engine , where at the bottom end of the scale,
from a standing start, the engine does not respond as quickly as it did with the
new CDI units in place but at the top end of the scale the bike just keeps
wanting to go faster and faster. I forgot to tell you the numbers on the bottom
of the CDI units, on the 1988 (VH) version the numbers are MM9 CI 529, and on
the 1996 version the numbers are MSA CI 558."
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5. C.D.I.
stands for Capacitive Discharge Ignition. It is the unit responsible for the
switching of the current that passes through the primary of the ignition coil.
In this way, high voltage is supplied to the spark plugs and spark is generated
at the correct timing. See here
for a detailed description.
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6. To calculate the typical current
available for accessories, we must subtract from the alternator output
(about 310 Watt for 87-89 and 94-99 models, 350W for 90-93 models) the maximum
consumption of the standard equipment, as follows:
Headlight low-beam 55W
Headlight high-beam 60W
Parking light front 4W
Parking light rear 5W
Turning light + indicator 25W
Rear stop light 21W
CDI system 10W
Charging system 20W
Neutral + oil + high beam indicators 8.5W
Instrument panel lights 10W
Horn 24W
Cooling fan 24W
Tachometer + Temperature gauge lights 5W
TOTAL Consumption: 272W
Remaining power: 38W (78W for 1990-1993 models) at 5000 RPM. At lower
revs, alternator output decreases but CDI and charger current decreases too.
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7.
Recommended specifications for a new battery (you don't need to buy the oem HONDA
part):
12V / 11Ah / standard or maintenance free lead-acid battery. Of course the form
factor must be the same. The breather tube outlet must be located at the same
position with the original (if you don't want to bother with a tube re-routing).
A 14Ah battery is also acceptable (charging current is not significantly lower than
the required), as long as the form factor remains the same.
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8. YUASA YB-12-AA (and maybe YB23A-B) is exactly the same
with YB-12-AB which is specifically made for the Transalp, except from the
ventilating tube position. Usually it is significantly cheaper than the original
part. To install it, you must carefully re-route the breather hose. It
seems there is no problem with electrolyte spilling etc if you do this right.
Many TAers have posted that they installed this cheaper alternative without
problems so far. However, if you afraid of doing it wrong, I suggest to stay
with the A-B model.
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9. Jumpstart is a method to start an
engine when the vehicle's battery is unable to do it. You need another battery
(mounted on a vehicle or not) and a pair of thick cables to connect it to your
bike's battery. Watch out to connect the same polarity leads. Christos Zervos wrote:
"A jump start will not harm your bike, as long as the other car (or
bike) has its battery installed in its electric circuit. However, do not run the bike
without a battery."
I should add that it is better for the other vehicle to have its engine
running. Also be careful because there might be a short-circuit in your bike
electrical circuit. In some rare cases, such an overload could cause an
explosion of the external battery. Keep your face away of it batteries and wear
some kind of eye protection.
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10. In order to adjust the headlight
beam, the plastic instrument panel cover (dashboard) must be removed. Then,
you follow a procedure like that posted by Eddie Hall:
"In the HONDA service manual for 1989/90 Transalp and those with similar
headlamps:
Looking straight on at the headlamp from the front of the bike, there are two adjustment screws. One to the right of the lamp (3 o'clock position)
and one in the center, just below the lamp located through a small hole in the cowling. The lower one is for vertical adjustment (clockwise turns move
the beam downward) and the one to the right is for horizontal adjustment (clockwise turns of the screw move the beam to the rider's left)."
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11.
To verify the proper adjustment of the headlight beam (medium scale) you need a
special tool with lens and a small projection screen. If this is not available,
you must place the bike in upright position, at the right side of a dark street,
about 30 - 40 m away from a car parked at the left side of the street and facing
towards you. Adjust the beam so that only
the lower part of the car's front screen is lightened.
If you plan a long trip with pillion and luggage, adjust the beam with that
load, otherwise the beam will be moved annoyingly higher, into the opposite
driver's line of sight.
The above tip have been posted by Christos Zervos.
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12.
To replace the headlight bulb, first
remove that dark-gray dashboard. You don't need to remove the whole front
cowling.
The bulb is somewhat "bolted" in its socket, on the rear side of the reflector
(about 1/4 of a turn).
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13.
It seems that this water condensation problem affects mainly the front
right indicator. Here's a post from Markus Kunkel:
"I have had this problem with the right front indicator. As long as the indicator will work, you have no problem.
But someday it stopped doing it's job on my TA. The socket of the bulb was corroded. So I disassembled the
indicator and put some silicon (like you use it for components in bathrooms) as sealing between the yellow
glass-part and the part with the socket. From that day on, the indicator is free from any water and works
properly."
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14.
The switch on the clutch lever is needed for the following feature:
When the gearbox is not in the neutral position, bike cannot be started, unless
clutch lever is depressed (and the side-stand is not used, but this latter
condition is
not required in older TA versions).
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15. It is essential
not to leave the battery to reach a certain amount of discharge. After that point,
battery performance and lifetime is reduced and this effect is usually
irreversible. As a general rule, do not leave battery voltage to drop below
10.8V. The rate of battery discharge is depended from the stand-by load (an
alarm) and the
self-discharge rate (the latter is strongly temperature dependent: rate is higher in hot season). Further calculations and
suggestions can be found at my
Batteries
page.
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16. If
you suspect there is a current leakage when ignition (main) switch is off,
you have to measure it. However, it is easy to get incorrect results from any
high input impedance digital voltmeter (DVM) when measuring on corroded (or just simply exposed to weather
conditions) copper wires.
The most reliable leakage test is to disconnect the battery negative (or positive) terminal and connect a current meter in series. Supposing you
have not installed any alarm on the bike, there will not be any initial current surge, so your milliamp-meter will be safe. If you feel unsafe or
you have an alarm installed on the bike, just connect the current meter with its leads initially short-circuited, wait a few seconds and then
remove short-circuit to read the actual current. The leakage will be 2-5 mA
if you have an alarm installed, otherwise it must be well below 1 mA (usually in
the order of a few microamperes).
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17.
It's not exactly easy to tell if the battery is bad by considering the symptoms
on bike's
operation. A general rule says that measuring voltage is not sufficient because
the internal resistance may have been increased. Look at my Batteries
page for details.
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18.
Cheap chargers are not specifically made for TA battery. This is because
their charging current is not adjustable (actually, they limit charging current
just using their transformer equivalent resistance). Thus, the current might be
higher than 1.1A (the rough upper charging current limit, when temperature
sensing is not used), so the battery will be overheated.
To scamp up a very simple and cheap charger, look again at my Batteries
page.
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19.
When starter rotates freely (failing to engage and start the engine), first
check the battery, not the starter itself. In most cases starter is OK,
however battery has reached the end of it's life (but always check the fluid
level!) or (very rarely) the charging circuit is malfunctioning. Measuring
voltage doesn't help, because there may be internal short-circuits or increased
internal resistance. A quick way to find out is to jumpstart the engine with
another vehicle's battery. If it really starts, try to charge the battery by
running the motor for a while (if you had left the vehicle hibernated for a long
time). If in the next days you see the same problem again and you are sure the
charging circuit is OK, head on for a new battery ! If it doesn't start at all,
check all related electrical connections for increased resistance and clean them
carefully.
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20.
About the repeated blows of the main fuse when staring the engine, Detlev
Mueller wrote:
"I had a similar problem last summer. In fact, the symptoms you
describe, sound very familiar to me. Most probably, I guess, your bike suffers from an electrical short cut, due to a defective lead. First I would
suggest, check the leads around the steering stem. This happened on my bike. Everything was fine during ride, but after parking and locking it,
with handle bar turned left, the fuse was blown. I replaced it, started the engine - everything was fine. Turned left - dead. After noticing
that, I found a bad isolation on a lead next to steering stem, thus, when turning handlebar left, the lead touched the frame - and <flaaash>.
After fixing it, there were no problems at all."
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21. Rarely, instrument lights
might be burnt out. Tony Ogilvie wrote:
"I burn out instrument lights all the time or at least two complete sets
in 40,000 miles. I think it has something to do with the amount of vibration at the instruments. I replaced one of the
bulbs to find the others burned out a few days later. My advice is to order 5 new
bulbs (#37237-SA5-003) as not to repeat the problem again. I replaced mine by removing the upper gray
covers."
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22. When a turning light is flashing
much faster than normal, check for the corresponding front or rear bulb.
Surely one of them is burnt out or the socket is heavily corroded or a cable is
broken. When the load of the turning light relay is lower than the specified
one, flashing rate increases.
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23.
When one (or both) turning light show a delay before operate:
a. The turning light switch may has increased resistance. Dismantle, clean and
lubricate it with suitable graphite grease.
b. Check the bulb socket for corrosion.
c. Replace the old turning light relay (it is located under the dashboard) with
a new one. The latter better should be an electronic (solid state) relay. Such a
part can be found at an automotive parts store.
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24. Before trying to open the CDI unit
and re-solder the joints around the connector (or purchasing a new unit), check
the condition of the corresponding CDI plug on the bike wiring. Sometimes this
plug also breaks under the pressure of the seat. Thanks to George Alexiou for
the tip.
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25. When battery fluid needs frequent
fill-ins, check the charging circuit for excessive end-of-charge voltage
(particularly under high ambient temperatures). Voltage shouldn't be in excess
of about 15V (however, to my knowledge, there isn't any temperature compensation
inside the charger unit). Otherwise (more possible), the moment of purchasing a
new battery is approaching!
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