Re: 78 Maxi Tail Light Gremlin

It sounds like a longshot, but I mean it's 1/2 of the equation of what's generating the power...

Re: 78 Maxi Tail Light Gremlin

I'll give it a whirl tomorrow. If that don't do it, I'll try a brake light coil in the tail light coil's place like you suggested. I was hoping to fix it proper.

Re: 78 Maxi Tail Light Gremlin

ahh, taillight wiring ok... it might by on the headlight side. thats gotta work right to trigger tail light.

Re: 78 Maxi Tail Light Gremlin

> pat splat Wrote:

> -------------------------------------------------------

> ahh, taillight wiring ok... it might by on the headlight side. thats

> gotta work right to trigger tail light.

I've been wondering that too, Pat. Because the headlight works fine, unless I "accidentally" short out the speedometer light wires, which feed right off the headlight. When this happened, the headlight quit, but the taillight started working.

I noticed this when I discovered the speedo light wires touching the speedo mounting bracket. But when I straightened the wires so they couldn't touch the bracket, the headlight came back on and the taillight went back off.

Re: 78 Maxi Tail Light Gremlinrounds

Probably Fred /

Did you set coil/coils air gap to flywheel to factory puch repair manual gap specs and is all grounds including brown frame wires connected correctly? (edited)

Re: 78 Maxi Tail Light Gremlinrounds

No, I didn't set any coil air gap, but I've checked every ground wire on the bike.

Re: 78 Maxi Tail Light Gremlinrounds

Probably Fred /

> Seth B Wrote:

> -------------------------------------------------------

> No, I didn't set any coil air gap, but I've checked every ground wire on

> the bike.

I suggest you do

BA1EA691-6FE2-4AFE-9EB1-650B0613F979.jpeg

Re: 78 Maxi Tail Light Gremlinrounds

I might add : the closer the magnets are to the coil poles , the better the coil performance .

Re: 78 Maxi Tail Light Gremlin

Speedo bulb is working and is the correct wattage etc?

Re: 78 Maxi Tail Light Gremlinrounds

Ken, I'll check the air gap. I haven't seen that before you pointed it out.

Mike, I don't know if the speedo bulb is working or not, I neglected to notice. The bulb may be burnt out.

Re: 78 Maxi Tail Light Gremlinrounds

Maybe disconnect the speedo bulb wires and see if there is there any change

Re: 78 Maxi Tail Light Gremlinrounds

Probably Fred /

> P D Wrote:

> -------------------------------------------------------

> I might add : the closer the magnets are to the coil poles , the better

> the coil performance .

Too close and you’ll burn out tail light bulbs, Too far and no light/dim light so keep to factory specs,

You need to bend or narrow feeler gauges to get accurate reading

Re: 78 Maxi Tail Light Gremlinrounds

Okay, I checked and adjusted the coil air gap to 18-20 thousandths. I removed the speedo bulb socket from the speedometer. The speedo bulb was good, bright at idle, but no taillight. I removed the speedo bulb, and still no taillight. I revved the engine, and the speedo light blew, but no taillight. I changed the bulb, and stil no taillight. Wondering why the speedo bulb blew, I checked voltage at speedo bulb, with headlight on. At idle I had ~8 VAC but at half throttle it was 18-19 VAC. Is this way too high? Seems like it to me. Maybe headlight coil putting out too much? Now what?

Re: 78 Maxi Tail Light Gremlinrounds

Ummmm is there any chance your horn wires are switched with your speedo wires? Totally spitballing at this point

Re: 78 Maxi Tail Light Gremlin

I'm thinking run a temporary ground from the engine block up to the headlight/speedo ground... can't remember but I think that gets grounded from the light switch through the handlebar which is not exactly a strong path

Re: 78 Maxi Tail Light Gremlinrounds

No, they're not, the black/yellow goes to th light, and the blue/black goes to horn. I've even tried two different horns, doing my own spitballing.

The only thing I haven't changed is the switch assembly. It has the big square plastic switches.

Re: 78 Maxi Tail Light Gremlin

I tried the ground. Providing a direct engine ground doesn't change anything. The only way the taillight will come on is if I ground the positive lead of the speedo light. As soon as the headlight circuit is grounded, the taillight comes on. This of course kills the headlight.

Re: 78 Maxi Tail Light Gremlin

In the interest of troubleshooting, have you tried swapping out a different headlight lighting coil?

Re: 78 Maxi Tail Light Gremlinrounds

Probably Fred /

> Seth B Wrote:

> -------------------------------------------------------

> Okay, I checked and adjusted the coil air gap to 18-20 thousandths. I

> removed the speedo bulb socket from the speedometer. The speedo bulb was

> good, bright at idle, but no taillight. I removed the speedo bulb, and

> still no taillight. I revved the engine, and the speedo light blew, but

> no taillight. I changed the bulb, and stil no taillight. Wondering why

> the speedo bulb blew, I checked voltage at speedo bulb, with headlight

> on. At idle I had ~8 VAC but at half throttle it was 18-19 VAC. Is this

> way too high? Seems like it to me. Maybe headlight coil putting out too

> much? Now what?

Wiring incorrect maybe

If the speedo light blows its the headlight is blown or circuits or grounds for the headlight is wrong, a simple wiring problems that something is not right soon as you find out whats right you will say wow that’s all it’s it

Re: 78 Maxi Tail Light Gremlin

Richard Eberline /

The tail light has a bad ground to the frame thru the fender. Try another ground wire from a good ground spot near the the engine to the ground on the bulb.

Re: 78 Maxi Tail Light Gremlin

> Richard Eberline Wrote:

> -------------------------------------------------------

> The tail light has a bad ground to the frame thru the fender. Try

> another ground wire from a good ground spot near the the engine to the

> ground on the bulb.

Richard, I thought maybe the same, but the taillight ground wire goes directly to the wiring block, then to engine block. It does not ground to the fender. Unless I have a bad wire, that ground is good. I

Re: 78 Maxi Tail Light Gremlin

This is the wiring diagram closest to my setup. So many ground wires! I have been all over this motherF. So many times. I'm walking away from it for a few days before I drown it in the river.

image.png

I'm really starting to lean in Pats direction, and one of my ground wires is hanging on by one strand, showing continuity and voltage on my meter, but not carrying the load. Then when I ground the headlight circuit, it uses that path to ground. I don't know what else to try, other than a different light coil, but I don't think that's it; I've already tried a completely different stator assembly.

Re: 78 Maxi Tail Light Gremlinrounds

Oh that's right I forgot you tried a whole different stator. Scratch that suggestion. Replace the grounds for good measure then

Re: 78 Maxi Tail Light Gremlin

Probably Fred /

The ground is through the fender likein 3 wire system,

One wire is tail light, ground is fender,

One wire brake light, other is fender,

All brown wires need to be connected to frame including brown wire to frame by buss block !

Re: 78 Maxi Tail Light Gremlin

> Ken Roff Wrote:

> -------------------------------------------------------

> The ground is through the fender likein 3 wire system,

>

> One wire is tail light, ground is fender,

>

> One wire brake light, other is fender,

>

> All brown wires need to be connected to frame including brown wire to

> frame by buss block !

There is three wires coming off the back of the taillight. Grey, blue/green, and brown. All three wires connect at the wiring block. the brown wire does not ground at fender, but at wiring block then directly to HT coil bracket.

The brown wire from the taillight goes:

Taillight >> wiring block >> engine case.

It does not ground thru fender.

Re: 78 Maxi Tail Light Gremlin

image.jpeg

Fourth row from the top, green/black wire on the right, two brown wires on the left. One of those brown wires comes directly off the taillight. The other goes directly to the HT coil bracket bolt. All brown wires connect at this HT coil bracket bolt.

Re: 78 Maxi Tail Light Gremlin

EDDA1C65-29D2-4D06-AC9F-AE66DF54CA8D.jpeg

In the bottom right corner of this picture you can see where all the ground wires connect to the HT coil bracket.

Re: 78 Maxi Tail Light Gremlin

I think a wire conductor may be broke at one of the ground wire ring terminals, caused by repeated flexing. I'm gonna check those again.

Then TNT.

Re: 78 Maxi Tail Light Gremlin

Probably Fred /

> Seth B Wrote:

> -------------------------------------------------------

> > Ken Roff Wrote:

>

> > -------------------------------------------------------

>

> > The ground is through the fender likein 3 wire system,

>

> >

>

> > One wire is tail light, ground is fender,

>

> >

>

> > One wire brake light, other is fender,

>

> >

>

> > All brown wires need to be connected to frame including brown wire to

>

> > frame by buss block !

>

> There is three wires coming off the back of the taillight. Grey,

> blue/green, and brown. All three wires connect at the wiring block. the

> brown wire does not ground at fender, but at wiring block then directly

> to HT coil bracket.

>

> The brown wire from the taillight goes:

>

> Taillight >> wiring block >> engine case.

>

> It does not ground thru fender.

You may have the pre 1978 dreaded five wire system/Stator not six wire installed

All my bikes have 6 wire Stator and harness and do not have ground wire to tail light from buss just a little brown wire that goes to fender tail light mounting bolt to taillight, there should only be a gray and (blue I believe?) that goes to the tail light from buss and tail light is grounded through fender and that little brown fender wire (edited)

Re: 78 Maxi Tail Light Gremlin

It is definitely a six wire stator. And all three taillight wires definitely go to the wiring buss block. I completely physically removed the taillight to check that ground first. This one is confusing the heck out of me. I'm good with electrics usually. It's gotta be a bad ground wire or connection somewhere.

I'm tempted to throw a whole different harness with the oval switches on, but I like this setup with the square switches. Plus it's a huge pain in the ass.

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