Starting problems

Hi every one thanks for the add to the group 

I have a 1996 p regarding vfr750 bought from a salvage auction with only the back lights broken of 

when I got the bike home after a quick check over there was a bit more to this bike than I first thought 

battery missing,valve ripped from rear wheel and it’s had a alarm fitted and wires chopped of it 

anyway put booster pack on the battery terminals ignition on and yes we have full lights but when pressing the start button it dims the dash and headlights 

and refuses to turn over just a slight noise from what seems to be coming from under the speedo/ Rev counter when I bridge the solenoid it will turn over but won’t start same when I run a live from battery terminal to the starter wire it will turn over and melting the bit of wire I’m using any ideas does it need a stater I’m about at my wits end with it 

Hi and welcome!

These two are clues:

1. "pressing the start button it dims the dash and headlights and refuses to turn over just a slight noise from what seems to be coming from under the speedo/ Rev counter"

2. "bridge the solenoid it will turn over but won’t start"

Regular start-circuit is bypassed and disconnected. Most likely from alarm, which typically is inserted between start-button and rest of harness. Best bet is to refer to official wiring-diagram (part of manuals download from here). Then trace each and every wire of starter-circuit in wiring-diagram and match to what you physically have. Most likely you'll have segments cut off due to alarm. Have to remove ALL traces of aftermarket wiring from alarm, and re-connect factory wires back together.

+1 for Danno's suggestions.

The click noise from behind the instrument panel is most likley your Headlight Relay which drops out as you press the Starter Button, a normal function.

You need to establish 12v at the Yellow/red wire of the starter relay when you press the starter switch, and a proper ground on the Green/red wire, you need to check this via the wiring diagram as the Starter Relay saftey logic is via these two wires. Ignition Switch, Kill Switch, Neutral Switch, Clutch Switch and Sidestand Switch all effect the Starter Relay logic.

Also check the state of All fuses.

Thanks guys it had a alarm fitted and someone has chopped the wires of it 

it sits under the seat I’m just thinking would i be better of reposing the wiring loom 

as there is looms avail on eBay for £40 

Its your call. Depends on how much damage to how many wires. Working with colour coded wires and re joining them is not too difficult.

Hahahaha funny you should say that I’ll grab a picture of it shortly every wire is  black lmao 

14 hours ago, Bigyin32

Hahahaha funny you should say that I’ll grab a picture of it shortly every wire is  black lmao 

Not a Honda motorcycle I'm aware of that has only black wiring!

If you don't have the Service Manual you can download it from the forum.

UI would be surprised if after 25 years in Scotland wires were not black. Wifey watches “Outlander”, I take peek now and then, looks like Scots still cook over open fire? 😉

Honda uses color-coded wires, so any black ones are probably the alarm wires.

Ciao,

JZH

I would hazard to say that there is no vehicle manufacturer on this Earth who doesn’t use color code wires nor they could.

First manufacturing, the way harness is made, flat table plus a lady weaving from connection location to location and second is diagnostics....

Bigyin32, 4/8/2021 at 6:24 AM

Thanks guys it had a alarm fitted and someone has chopped the wires of it 

it sits under the seat I’m just thinking would i be better of reposing the wiring loom 

as there is looms avail on eBay for £40 

that way madness lies.  installing a loom with all components in place is a difficult and frustrating job best avoided if possible.  on he other hand, splicing wires is dead easy.

4 hours ago, squirrelman

that way madness lies.  installing a loom with all components in place is a difficult and frustrating job best avoided if possible.  on he other hand, splicing wires is dead easy.

yeah, there's lots risk with replacing harness.

1. unless you are buying brand-new harness from authorised Honda dealer, how do you know harness is 100% functional? You'd have to test each and every wire from end-to-end to verify it's Ok. That effort is best done on existing harness to find where fault are.

2. Another potential pitfall is introducing additional errors into system. Wires and connectors may be broken in swap. Or not firmly clicked into place. Again, requiring end-to-end testing.

For all that effort, easier to just test existing 5-8 wires involved in starter circuit on existing

harness. Remove all extra alarm circuitry. Reconnect factory wires that had been intercepted by alarm. Also test interloc ground safety switches as Grum mentioned.