78 AMF Resistor

So I have a 1978 AMF A110 Roadmaster and I recently bought it off someone and I found the resistor was missing causing both lights to burn out very quickly. What kind of resistor and what ohmage should I get?

If I can’t find one, what can I do to counteract the burning out?

Listed photo with 2 being the resistor

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Re: 78 AMF Resistor

If the resistor is missing it should only affect the brake light, not the tail light or head light. If your head light and tail light bulbs are blowing without the resistor, something is miswired.

I looked at the AMF manuals and wiring diagrams, but unfortunately the value of the resistor isn't listed anywhere.

I'd try like 5Ω. If that still results is blown bulbs, go lower. If the brake light is super dim, go higher.

Re: 78 AMF Resistor

Re: 78 AMF Resistor

While I’m on that topic, apparently I’m using the wrong headlight too, right voltage. Wrong wattage. The manual calls for (picture below) and I can’t find them, what’s a good equivalent?

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Re: 78 AMF Resistor

If I were you I'd get a modern 4.5" lens assembly with replaceable bulbs. Like this: https://www.treatland.tv/universal-moped-headlight-black-with-chrome-rim-p/best-headlight-in-the-land.htm

If you really want to stick with a sealed beam unit, a 6V 18W one will work: https://www.mopeddivision.com/moped-make/derbi/ge-6-volt-18w-sealed-beam-bulb-slide-terminals/

Re: 78 AMF Resistor

And these are trustable websites?

Re: 78 AMF Resistor

And for the one with changeable bulbs, what kind of bulbs would it take? And would it work with this housing?

(Also, excuse me for asking this makes me feel silly but I’m still a rookie at these bikes. What’s the connectors for the headlight and what’s the ones for the resistor)

image.jpg

Re: 78 AMF Resistor

Tri-ped Dave O.D.B. /

The housing on the roller AMFs mounts completely different so stick with the stock housing and just get the 18W sealed beam

Re: 78 AMF Resistor

> Tri-ped Dave O.D.B. wrote:

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

> The housing on the roller AMFs mounts completely different so stick with

> the stock housing and just get the 18W sealed beam

Good advice; I don't know much about AMF's specifically.

> Charles Ferro wrote:

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

> And these are trustable websites?

Treatland, mopeddivision, and dos cycles are indeed trustable websites.

Re: 78 AMF Resistor

♣Slew Foot♣ /

If the old one is there the color bands id it. 8Ω usually or 3.5 feet of wire curled up...

Re: 78 AMF Resistor

Old one was long gone, and for the 8 ohm one, where could I find one with those slide on connectors?

Re: 78 AMF Resistor

♣Slew Foot♣ /

Or...

Derp.

Re: 78 AMF Resistor

> Charles Ferro wrote:

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

> Old one was long gone, and for the 8 ohm one, where could I find one

> with those slide on connectors?

Maybe an auto parts supplier? However, those sure look like quick disconnects. You can buy the connectors and a crimper for real cheap. (edited)

Re: 78 AMF Resistor

And what wattage should it have, I’ve found 8 ohm ones but there a lot of different wattages. I’m getting a 18w bulb so should I do less than that wattage or more, like 20 watts for the resistor?

Re: 78 AMF Resistor

Power = voltage ^ 2 / resistance

Therefore:

P = 6v^2 / 8Ω = 36/8 = 4.5W

A 5W resistor or higher should be fine. The headlight and taillight (in parallel with one another) are in series with the brake light / resistor parallel circuit, so the actual applied voltage will be less than 6V even at high rpm.

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