1987 VFR electrics/starting/fuses

I just picked up a 1987 VFR700F2. It came with its share of issues, one being that the main/starter relay panel needed to be rebuilt.

Well, I took apart the relay panel and rebuilt it. I threw in a new battery (the old one was showing 4.8v!), too. At this point, attempting to start the bike yields the electric fuel pump activating but no starter engagement.

Looking at the starter, I only see the one lead from it -- a 4ga or 2ga ground wire that goes back to the M post on the starter relay (the other connector on the relay, marked B, carries the positive battery cable; the battery itself grounds to the frame). I can't find the hot wire to the starter. However, I checked resistance across the ground cable and am getting .2-3 ohm, so the cable's good.

One fluke: Even with the key in the off position, so long as the fuse is in place in the starter relay block, I get power to the dash (my NEUTRAL light is illuminated). I have to pull that fuse to kill all power there. (If I have to rig up a kill switch based on a fuse, well, no big deal.)

I took the relay down to my local bike shop and it tested good. They suggested that I check the fuse panel for breaks or blown fuses.
Thing is, I can't FIND the fuse box. At all. The bike's stripped down to the frame, so it's not hiding behind a fairing. The closest thing I can find is a connector grid where the upper-right fairing would be, but that is obviously an OEM part and does not at all have any fuses or places for fuses. As far as I can tell, the only fuse to which I have access is the 30A starter relay fuse!

After poking around for a couple hours, I'm stumped. Just for kicks I reassembled the relay block in the same fashion as it was originally, but now every time I put power to it the 30A fuse blows; I've gone through 3 fuses now. What on earth. . .?!

So, more-knowledgeable VFR enthusiasts, any clues? Where should I look for the fuse box? How is the starter powered -- certainly it's not with a little 12ga somewhere, is it? Why, all of a sudden, am I blowing fuses across the starter relay when it goes hot?

(External links
-Universal starter relay, looks identical to what's on the bike:
http://www.atvworks.com/prodimages/SND6058sm.jpg

-Universal starter relay parts, like what's on my Viffer:
http://images.motorsportdealers.com/common/MediaLibrary/CatalogImages/650/500/38684d74e9.jpg

Thanks, folks!

 

With wiring all in bits it's not easy to tell what's up, but you MUST first aquire a full wiring diagram for the bike. The wire color- codes are useful for tracing component leads.

Touch the starter switch (solenoid) fat "M" wire up to battery + and starter should spin......

 

Side of the bike, back to front; where, oh where, can my fuse block be? Also, yes, that's my CBR there too.



Close-up of the starter relay. Looking from the top:

[30A FUSE]
[GR] [YR]

[R] [RWRW]

[+] [-]




Where on earth is the hot lead for the starter?



My fuse block: Here?



This connection junction appears to have no fuse panel.


What am I doing wrong?

 

And, surprisingly to me, connecting the starter cable (that goes to M on the relay) to the + battery terminal results in the starter engaging. That seems odd, as in testing I get 12.5v from the + terminal to the starter cable attachment, which would indicate to me that it should be a ground.


Sadly, electrics aren't my strong suit.
And I keep snapping fuses. Rats.

 

Found the fuse box. It's in a panel underneath the gauge cluster.
The only fuse I was really interested in was the 10A IGNITION/FUEL blade. It looked fine, but I replaced it with a new one just in case. Now I need to solve the starter/relay mystery.

 

When blowing fuses, it helps to unplug all the fuses and one by one, put them back in until you find the circuit that blows the main fuse.

Make sure the starter relay can handle 30 amps. There are several out there that only are set to work up to 20 amps. The cheap starter relay is not the way to go here.

 

I am pretty sure the starter relay is set to handle 30A. All the relays I looked at have a 30A fuse, and this one came equipped with same.

Good idea re: pulling all the fuses.
But. . . hmm. I'm blowing fuses before even turning the ignition on; the fuse snaps whenever I put the hot lead to the starter relay.

 

Sounds to me like a short in the starter relay - or it's wired incorrectly.

I know you had the dealership test the relay. I would pull it and test it again and make sure it's not shorted out.

If you have a multi-meter (if not, get one), you can test the relay by measuring the resistance between the two low current leads on the relay, if it's infinity, the relay is probably bad. If it's zero (literally) then the relay is probably bad.

 

The starter motor only has one power wire; the one that connects to the relay. When you push the starter button, the relay connects the battery side terminal to the starter motor terminal. The starter motor is grounded through its metal case to the engine block, to the frame.

It sounds like you somehow have the main fuse in line with the starter motor. Starter motors are not fused, due to their extremely high current draw. The starting relay should be fused, but not the motor.

There should be a wire directly from the battery positive terminal to one terminal of the starter relay. The other terminal on the starter relay should go directly to the starter motor. Typically, power for the electrical system comes off of the battery side of the starter relay and goes a very short distance to a main fuse.

The first picture shows a red cable going from the relay to the chassis. That is wrong...

And the text you inserted in the one picture that says, "single 4ga wire grounds, goes to M on starter relay"; what do you mean by "grounds"? Does it measure a low resistance, or is it physically grounded? It should go directly to the relay.

Hope this helps a bit.

 

I figured out, finally, that the starter motor was grounded through the engine case (what a duh moment for me; I've worked on starters before, I should've known this). It's not a ground, it's a 4ga to the relay, which should energize through the other (positive) cable to the battery.

In the first picture, that red wire is not going to the chassis. It's hanging off the starter relay. I'd simply disconnected it from the POS terminal and took a picture of it, rather than hold a live relay in my hand and risk shorting something by jostling it.

I do have a multimeter. If it's infinity, the relay's bad; if it's 0, the relay's bad? I'm confused there. Can you clarify, please?

 

Please disregard my post. Lgn001 has a better handle on it than I do. Sorry for any confusion.

 

You are going to need two people or alligator clips for your meter leads.

A relay is nothing more than a magnetically operated switch. When you energize the relay (the small terminals), an electromagnet physically engages a large set of contacts to electrically connect the two large terminals.

So, for the sake of clarity;

1. Disconnect the starter motor wire from the relay.
2. Set your multimeter to read DC voltage.
3. Put the negative meter lead on a chassis/ground connection.
4. Put the positive meter lead on the large relay terminal that the starter motor wire would go to.
5. With the ignition ON, the meter should read "0". When you push the starter button, the meter should read "12" or "13" or whatever your battery voltage is. When you let go of the starter button, it should return to "0".

I suspect that the relay is good, but you might as well check it to make sure. From what you posted before, the starter motor works when directly attached to the battery side. You may have to get REALLY basic here, but one step at a time.

Was the wiring spliced like that when you got the bike? I ask because you should NOT have power to the neutral light and dash with the key off. This might get interesting...

 

I just reassembled the wiring. Somehow I managed to get rid of the short so that I'm no longer blowing fuses (also, I found the cap for that fuse -- it's supposed to be a 20A, not 30A, fuse!) across the starter relay.

Now when I turn on the ignition, all my lights come on and the fuel pump engages.

Lgn001, I took your advice and enlisted my wife in this test.
Positive to positive, relay to battery, disconnect starter wire.
I put the negative lead on a chassis ground (and to make sure it was a good ground, measured voltage from the positive pole; 12.4v). Positive went on the starter wire side of the relay.
Ignition ON: Voltage = 0. Fuel pump engages, all lights come on.
Ignition ON, starter button ON: Voltage = 0.

Now, I can get the bike to cough and crank now. If I put the fuel line in a gas can and turn the ignition on and hit the starter button, well, nothing happens. But if I grab a screwdriver and stick it between the poles on the relay (thus creating a jumper), the starter coughs and the bike tries to fire; I get pulses out the exhausts and everything! Well, everything except ignition, but it's a step.

So, should I take the relay down to the shop again?

 

Can you hear or feel the relay "clicking"? If not, time to check the power to the relay itself.

There is either one small terminal or two small terminals on the relay. If there is only one, then the relay body must be grounded for it to function. If there are two, then one is probably a ground wire, and the other is the relay positive terminal.

You know, before I type this whole thing out, could you see how many small terminals there are? From the picture, the relay is just hanging in space. If it supposed to mount in a metal bracket that is grounded, that could be the problem.

 

I cannot hear or feel the relay clicking. I checked for that.

On the relay itself there are two terminals. One goes to the battery, and the other to the starter. They are labeled B and M on the relay block.

I just went down to the garage and noticed that I'd reversed the green/red and red-red, with GR in front and R in back. When I place GR anywhere on the back (fuse-side) of the relay, it snaps the fuse. That must be my short.

It's hard to describe the wiring. I'll just attach a couple photos.

 

My terminology was bad... now that I see the relay, the "small terminals" I was referring to are the small lugs located in the recess in front of the fuse. Are there four or two? The picture looks like four.

 

There are four. Maybe this will help. Let me see if I can make some sense.

I traced and pulled apart the junction for the twistgrip wires.
There was lots of water inside. WTF? Probably 10-15mL dripped out.
Anyway, I pulled apart the entire twistgrip assembly. Lots of wires there. I tested a few for continuity.

For the sake of brevity, "OK" = <.5ohm resistance.

Yellow/red: Starter button assembly.
Button-Panel: OK
Now, this is also the wire that goes to the starter relay, so I tested it from the junction to the relay. OK there too.

Black/Pink: Starter button assembly.
Button-Panel: OK

Black: Start button AND kill switch.
Button-Panel: OK
Kill switch-Panel: OK

Black/White: Kill switch
Button-Panel: OK

Red: Ignition terminal
Relay-Ignition: OK

Now, there are a couple wires on the main relay I can't figure out. One's the twisted pair of (red/white)s, and one's the green/red. On a lark I probed green/red at the terminal and then looked for where it could end up.
Now, the fuel pump looks to be a replacement and it looks to be poorly installed, with several splices along its hot path. I stuck the other probe into one of the splices. BINGO -- <.3ohm.

So my wire that's shorting, my wire that keeps giving me problems, is the fuel pump. This would explain why, when I had it on backwards earlier, the pump kept coming on with the ignition switch (*facepalm*).
Now, testing G/R with other wires yields interesting results. Instead of getting infinity, when I test it across with the Y/R wire I get 35ohm. Testing with R yields 40ohm. So there MUST be a problem somewhere; I should probably just rip all those crappy splices out tomorrow and replace them with a single, unbroken length.

Now, with the red-white pair connected to the relay, red for ignition and yellow for starter button, hooking everything up. . .
Ignition ON: no lights/action.
Start button: Fuel pump activates. No starter motor activation.

I feel like I'm piecing this together, but I'm learning as I go along too.

By the way, you're a huge help -- thanks. I've done lots of automotive and motorcycle stuff before, but this is my first time tackling wiring head-on.

 

There is one more piece of the puzzle that needs to be addressed, and that is the starting relay. After I saw the picture, I realized that the battery power was routed internally through the relay to the fuse, and then to one (or two) of the small lugs. The other two small lugs are for the starter relay coil. I'll draw a picture and post it in a bit, using numbers to identify the terminals to keep us on the same page.

 

I sure do appreciate it. Thanks.

 

I think I remeber how to do this:



With the meter set for resistance, and a known good fuse in place, check between;

B and 1
B and 2
B and 3
B and 4

Remove the fuse and check between;

1 and 2
1 and 3
1 and 4
2 and 3
2 and 4
3 and 4

Might as well check these with the fuse out, too;

B and 1
B and 2
B and 3
B and 4