NEED HELP! Electrical gremlin

[Rob Cooker]

Bought a 2002 Vmax non running project pretty cheap. Let me start by saying I am no bike mechanic, have rode plenty worked on very few.

When I bought the bike the guy told me it wouldn't turn over at all, and the he thought the fuel pump was bad. Got it home battery was toast, replaced that no fire from ignition switch, crossed the solenoid posts it turns over fine and spray a little gas in the carbs and she fires up and purrs like a kitten until it runs out of gas.
The kill switch, start button were broken replaced with a new Yamaha part, still no ignition. All fuses are good, no issues there. I dont have Fuel pump, headlights, V boost or horn.
What the heck could it be? TCI box a relay I am not seeing? Clutch safety switch? Any help would be greatly appreciated.

 

[user 16790]

bad earthing ?

 

[sdt354]

bad earthing ?

Always worth checking grounds. The grounds on the right side of the frame I'd check. Harness connections?

 

[Rob Cooker]

The grounds look good but will clean them when I get home this evening. Any other options? Thanks

 

[Pighuntingpuppy]

The grounds look good but will clean them when I get home this evening. Any other options? Thanks

How good are you at reading wire schematics? When too many things are not working and not enough fuses to justify the issue, start back at the beginning. Grounds are and always have been problematic on Yamaha bikes. But when you can rule that out, head to the ignition switch. You need to start at the beginning of the power flow. Battery, fuse, ignition switch, more fuses, controls(whatever the circuit device you are looking for), and grounds. If you can read a schematic, it would help immensely for you and your electrical diagnosis.

 

[Rob Cooker]

I'm not completely useless with schematics, but also not a pro. Going to check the grounds in a few and go from there.

 

[Rob Cooker]

Checked all the grounds I could find, cleaned them no change. I can here the relay clicking but no headlight, no fuel pump, no V boost and no power to the solenoid. Is there one switch or relay that controls all of these symptoms?

 

[user 16790]

what is the actual battery like, does it give enough power when under load

 

[MaxMidnight]

The advice Mr Pighuntingpuppy give is spot on.

Rule #1 of diagnosis is 'Don't guess'. You may strike lucky but then again you are just at likely to waste time or money. Base your diagnosis on facts you have established.

Your bike isn't functioning because key components are not getting power.

Start at the battery and check you have power there; move along the key components; the main fuse, ignition switch, fusebox and so on.
At some stage you will reach a point where you no longer have power. The issue is therefore somewhere between the last OK point and where you loose power.

It may be a broken wire or a defective component sort that and you will arrive at a first time fix with the minimum of wasted time and effort.

Cleaning the earths is not a bad idea but I doubt that they will stop the bike.

 

[Rob Cooker]

The battery is new and turns the bike over when I cross the solenoid posts. I am trying to run down all the power wires.

 

[sdt354]

At the ignition switch, which is common to the components not working, battery voltage into, and out of needs to be probed? That's where I'd start at this point. Unplug it and test. Switches do wear out and malfunction.

 

[Drew_STNY]

Sounds like the main fuse should be the first check. Everything goes through that on it's way to the ignition switch.

 

[sdt354]

At the ignition switch, which is common to the components not working, battery voltage into, and out of needs to be probed? That's where I'd start at this point. Unplug it and test. Switches do wear out and malfunction.

Fuses all checked out as good. That's why I'd go to the ignition switch plug.

 

[Rob Cooker]

Ok this thing is literally kicking my ass. Found what looked to be a relay but had 2x 30 amp fuses. One side has power both spades, one side has no power at all. Also checked the wires to the solenoid has weak power on both sides.

 

[Pighuntingpuppy]

Presuming you are looking at the main fuse and ignition fuse? How do the fuses look? You will need to install good fuses, lift the fuse holders out to access the wiring underneath the fuse to see if battery power is carrying through.

One side of the fuse will always have power, the other side will not till a good fuse is installed. If power is carrying through the fuses on the wires, then you move down the circuit to the next control.

Say you are looking at the ignition fuse. Power carries through the fuse.....head up to the kill switch on the handle bars. Check for your power in and your power out. If that checks out, move to the next control on the schematic. Electrical diagnostics is pretty linear. Do not be intimidated by a whole bunch of wires. Look for a specific color in the circuit you are looking at.

I found an online service manual for the VMax that I was able to download if you dont have a hardcopy service manual on hand.

 

[Rob Cooker]

A schematic or diagram would be would be great tried to download a few but wouldn't open. All the fuses check good, all the coils are getting power with key on. Power to the solenoid on both sides but appears weak just using a test light. Can cross the solenoid and she will start with gas sprayed in carbs. Otherwise nothing no fuel pump, V boost headlight or ignition.

 

[[email protected]]

Ok this thing is literally kicking my ass. Found what looked to be a relay but had 2x 30 amp fuses. One side has power both spades, one side has no power at all. Also checked the wires to the solenoid has weak power on both sides.

Normal. One side is the main fuse, one side is a spare

 

[Rob Cooker]

Ok thanks didnt know. Trying to work blind, finally got a wiring diagram but not sure how much it will help

 

[MaxMidnight]

At the risk of sounding sarcastic, you could always buy (say) a Haynes manual which not only has the wiring diagrams but also gives you test procedures.

 

[Rob Cooker]

LOL sarcasm welcome.