voltage at coils??????

hi,

i built a custom harness for my 82 650maxim, basically everything works, headlight, tail/brake light, ignition switch, starter button/starter, yet i have no spark at the plugs... the bike cranks and cranks, just no spark...

I checked voltage at r/w, gray; and r/w, orange wires and im getting about 11.5v at both r/w's and the orange, but only 1.25v at the gray, and this with igntion on, but not trying to start.

Any ideas???
my coils are defintely grounded well, the metal blocks on both ends of both coils are bolted directly to bare metal. i have new plugs. coils and plug wires dont appear damaged, all solder connections are solid and shrink wrapped.

Could i have wires plugged in wrong at the TCI?

 

Here, how timely, just the thread for you to read!:


http://www.xjbikes.com/Forums/viewtopic ... tml#148847

 

yes, i read through this, but i've never heard a pop, and i still get voltage readings through the tci..

 

Start at the pick up coils, make sure they are sending, then test the TCI to the coils & the coils to the plugs.
Have you used all the right colors in the loom? have you used new connectors?

 

new connectors? yes
correct colors? yes (as far as i can tell) got a diagram from Gamuru here..

how exactly do i test at pickup coils? do i have to check them while the engine is cranking?
same with checking from coil to plug?

 

The fact is that what you describe can only be caused by a couple of things:

1. There is some high resistance is the coil or its plug. This is unlikely, but easy to check. Check resistance between the two pins of the plug to the coil - should be about 2.5 Ohms.

2. The TCI driver is shorted. This can be checked by measuring the resistance at the TCI box on the four-pin connector. Check the resistance between the pins that connect to the orange and the black wires. Then check the resistance between the pins of the gray and the black wires. These should be pretty much the same, and both should be pretty high. If they're not the same (likely the gray to black will be very low resistance), then your TCI box blown.

3. Assuming 1 and 2 pass, then, most likely, considering you built a new harness: you got something wrong in the wiring, and the gray wire itself is actually connected to ground somewhere. Disconnect the two-pin gray/R/W from the coil and disconnect the four-pin from the TCI box. Measure resistance from the gray wire to ground (should be open). Connect the four-pin back to the TCI box. Resistance from the gray wire of the two pin to ground should still be very high. If it's not, then you have a problem in your harness or pinouts where you're incorrectly routing the gray wire.

BTW, if 2 or 3 is the case, then you've been running straight DC through your coil and the coil is likely getting very hot. This may have damaged the coil in addition to whatever problem is the core cause of the issue.

Let us know,
Paul

 

great thank you so much for the tips, i will run through all of this today.

 

HAHAHAHA!!!!!!!!!!!!!!!!

Figured it out, the tests you gave me narrowed it down to wires being hooked up wrong at the tci box.

here is the correct order for the tci wires..

looking at the plugs on the box, left to right, like reading, with the indented clip side up;

6 prong: blank, orange, black
blank, grey, black

4 prong: Red/white, orange
Black, grey

trial and error.. seems every diagram i have is either backwards or upside down, lol who knows but i got it..

thanks alot

 

oh and just for readers of this post, my bike is an '82 650 maxim. so this diagram is for my bike and others like it, i dont know anything about the correlation between my bike and other models.

im sure it will help some folks!

 

ok so I think i have TCI trouble since its the last thing to check and my wires are slighlty different on the 6 prong. my bottom left is black w/ a white stripe, bottom right (under the solid black) is blank.

SQLguy, i get infinity when i check those colored wires on the 4 prong, but corolates to what you say on the 6 prong, approx 4.4ohms. You said the resistance should be pretty high, i think that's low, but that's the 6 prong lol. i get infinity on the 4 prong testing those colors.

can someone shine some light here? my main problem is the bike won't rev, idles mint. 82 650 Seca - non YICS but i don't think that matters

 

Your black/white wire is from the kill switch i'm pretty sure, it kills the TCI so no sparky spark. It could also be from the start safety relay.

I have that B/W wire as well on my TCI but it's not connected to anything in the 82 seca manual (same engine as mine) I should check that tomorrow and report back.

 

Also, yama, see my post in the xs400 thread.

 

Legend:
O = Orange
Gy = Grey
B = Black
R/W = Red/White

All Resistances taken with Black lead to ground.

One more bit of info, the O and Gy on the 4 pin is from the ignition coils (Should read ~ 2.75 ohms), the O and Gy on the 6 pin is from the Pickup coils. (Should read ~120ohms)

Always check resistance with the key OFF (no power, ohm meters can't have voltage present or they'll blow)

The O, Gy, and R/W wires in the 4 pin should all read 12V with the key ON (Wait 5 seconds after turning the key on to measure this, to make sure the TCI has turned itself off)


Also i'm pretty sure that the 2 B wires in the above diagram are redundant, as they are connected together internally for grounding.

 

went thru the same things on my virago wires found the same .R/W wires are supply voltage to the coils wich should read battery voltage the orange and grey come from the tci are trigger wires from the pu coils should read 1.25v if you bump the motor over with the meter still hooked up to the o or g wire you should see the voltage drop and spike back up. I could of swore something was wrong with mine also but was explained to me on another forum i found the problem with mine was caused by having a battery charger hooked up trying to start it with a bad battery. the frequency of the charger omitted the same signal as the pu coils. was talking to 1 of the tci rebuilders and he asked me to try a good battery. wich im sure is not the case with yours. also check the voltage stright off the battery should be about 1/2 volt to 1 volt more then at the coils R/W wires old connections with some resistance cause that make sure all connections are clean . will look for the post on that forum where it was explained to me