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Discussion Starter #1
Noticed that the headlight on rhe 96 savage seemed awfly dim. Both low beam and high beam. I had just charged up battery a few days ago. But im wondering if its the bulb itself. Seems if it was the bulb one beam would still be bright but I could be mistaken. Could the headlight be misaligned like cars? And how do you go about aligning them? I am just praying it is not an electical issue....we all know how fun those are......
 

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Hi Zippy
You said you had charged the battery a few days ago..Was that because it went dead? Have you checked the charging system? How old is the battery? I usually get around 4-5 years out of mine,
On one of my bikes I found had a problem with the charging system, I checked by taking a Volt Ohm Meter and with bike running and someone holding throttle at 3500rpm, holding the meter ends at appropriate positive and negative battery terminals, checked to see what it read, I knew I had a problem when mine only read 11.8 volts, meaning it wasnt charging, it should have read around 14+ volts.
On the other hand if it had read 14+ volts and my battery was still going dead, probably the battery unless there was an wiring issue. Thats just my method that works for me and I am sure others have their own tried and true method.
Do you have a repair manual? If you do it will show the factory method for checking the charging system.
I am unfamiliar with your particular bike so I suggest getting a manual and following their recommended troubleshooting method.
Regards
Ed
 

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if you are comparing that one to the headlight of the S40, think of the years between them...more than likely the Savage just has a lower wattage bulb....anyway, to see if it is electrical, start the bike up at night and see if the light gets brighter with higher RPM...it may not be the most accurate, but it will give you hint
 

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Discussion Starter #4
I had to charge the battery because the bike sat about a month and 1/2 without being on a tender. Light is very dim. Joe was riding behind me yesterday and u could tell that it just wasnt very bright. I will have the battery tested. I dont have a tester for her yet. But oh yeah I brought the clymers manual for it. Forgpt about that...duh me. I dont wanna keep driving her being dim stupid cagers cant see use with high beams.....
 

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You can get a multimeter for less than $20 either online or at many retail stores. It's an invaluable tool for the home mechanic and can eliminate a lot of guesswork.
 

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Discussion Starter #7
My son has a fancy multimeter he had to buy for school. It has so many buttons on the darned thing, I might be able to blow up Pluto with the darned thing. I'll wait till he gets home from work and have him test it. May not be a diesel truck, but I'm sure he can figure it out....
 

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Here's a valuable lesson on VOLTAGE DROP that will benefit anyone diagnosing dim headlights or other "underperforming" circuits...

Zippy, go get a beer, sit down, and take the time to learn this. You will thank me 1000 times over the next 10 years....as you help and teach others this simple but powerful diagnostic technique.

With your motorcycle turned off, measure your battery voltage. A fully charged battery is 12.6 or above. A 50% discharged battery is 12.3. (Surprised???)

You can't trust any diagnosis work you do unless you're working with a fully charged battery. Plug in a charger if necessary.

Start your motorcycle up. Have someone hold the throttle at 2-3000 rpms. Put your voltmeter across the battery terminals. You should see 13.8, something like that. That's alternator output charging voltage. It could be anywhere from 13.6 to 14.8. Above or below that, you have bigger problems...

Let's assume you have a solid 13.8 Volts

Next, leave one test lead on B+, and touch the other to the motorcycle frame. You should still see 13.8 or else you have a bad/loose/dirty battery terminal or ground strap.

Next, leave one test lead on B-, and touch the other to where B+ (the fat red cable) goes into your starter (assuming you can reach it...) You should still see 13.8 or else the battery positive terminal is loose or dirty.

Next, with the throttle still at 2-3000 rpms, measure the voltage across the headlight wires, WITH the headlight plugged in and illuminated. Dim or bright, either one...

(Probe either by stabbing the wires with a needle, backprobing the headlight, connector with the test leads, whatever, but DO NOT UNPLUG THE HEADLIGHT! It must be illuminated, current must be flowing through the circuit!

With dim headlights you're gonna see 11.8 or something like that, indicating a VOLTAGE DROP of 2.0 volts is occurring. You've got a bad or corroded connection, dirty or worn-out contacts in a switch, a bad ground, corrded fuzeholder, something like that.

For a headlight circuit you want a voltage drop of LESS than .2 volts for maximum brightness.

So now it's time to backtrack and find out where you're losing the 2 volts.

Start by putting ONE test lead on the battery negative, and the other on the headlight +. Do you still only have 11.8, or did the voltage jump up more than .2 volts. If so, you have a dirty, corroded, or otherwise "bad ground." Find where the headlight is grounded, to the frame or whatever, and clean it.

If both dim and bright are affected, since they share a ground connection, it's a likely suspect!

Next put a lead on battery positive and headlight negative. If you have a full 13.8 volts, then the voltage drop is occurring in the positive feed to the headlights.

You're trying to determine which "leg" of the circuit has excess resistance, causing a voltage drop to occur. Or it may be shared between both legs!

MEMORIZE THIS: A voltage drop occurs when current flows through an undesired resistance!

Now, mind you, Japanese manufacturers may run positive to the headlight all the time, and switch the ground on and off, or vice versa.

This whole testing technique is called "Voltage Dropping" a circuit, because the Voltage available to the headlamp is NOT the same as what is available at the battery / alternator output.

Some voltage has been "lost" or "dropped" somewhere along the way...

So now, you are going to continue to backtrack. Leaving ONE test probe on the battery the whole time, check the output of the headlamp dimmer switch, Maybe the contacts inside it are burned. Check the voltage at the output of the fuse holder for the headlamp You test voltage at every point in the circuit from the bulb BACK to the battery until you identify the connector, switch contact, relay contact, ground connection,... that is loose, corroded and causing the voltage drop to occur.

You start probing at the headlight, and walk your probe backwards to the battery, one leg at a time.

A little emery cloth will clean up most dirty contacts -- you don't ALWAYS have to replace the switch, especially if it's "white rust" from water ingress..
I've found spray contact cleaner seldom works....

A circuit must be POWERED UP and operating in order to perform a voltage drop test. Current must flow through a "bad ground" or "dirty contact" to create a voltage drop --- V =IR --- voltage equals current times resistance.

A dirty contact, bad ground, corroded fusebox may only add .2 ohms or so of resistance, but with a 10 amp headlight that creates a 2 volt drop --- 10A * .2ohms = 2 volts I * R = V.

Loose or corroded battery terminals, a corroded ground strap to the frame, a dirty ground connection at the headlamp itself... these things all add an undesired resistance.

(The resistance is TOO LOW to accurately measure with an ohmmeter, which is why we measure the VOLTAGE DROP it creates instead.)

Now, on my Subaru, MHI (stupidly) routed full headlamp power not only through the headlamp switch, but the worn out dimmer switch, and through pathetic 14AWG wiring. Headlights were yellow/dimmer than snot!

Instead of rewiring it in 12AWG, or even 10AWG, and paying $160 for a replacement dimmer switch, the solution was to install a headlight RELAY.

It didn't matter that the existing circuit only had 11.8 volts. That's plenty to switch a relay. I din't have to fix it! I wired the RELAY with 10AWG right to the battery, and from the relay 12AWG to the two bulbs.
(Actually 2 relays, one for dim, one for bright...)

That plus adjusting my (old, relay-style) voltage regulator up to 14.0 volts and my 30 year old Subaru had flamethrowers for headlights.

A half volt drop in available voltage can make your headlamps 50% dimmer. Yeah, that much!

So to recap: To VOLTAGE DROP a circuit it has to be operating, current has to be flowing. A bad ground, corroded switch or relay contacts, dirty connection, whatever, adds a small undesired resistance to a circuit (say .2 ohms) that creates a voltage drop as current passes through it. That prevents the headlights, or whatever, from receiving the full 13.8 volts, making them dim.

Voltage dropping a circuit is the process of comparing the voltage available at the battery (alternator output) to what's actually available at the headlamp, whatever, and then back-tracking to find the undesired resistance created in the circuit by dirty, worn, corrded contacts, connectors, ....

If you can understand and correctly perform a voltage drop test, on headlights or any other circuit, you are ahead of 90% of the auto and motorcycle mechanics in every shop in the country.

If you still don't "Get it," don't beat yourself up. Take this one-time chance to PM/Call me, let me go over it again with you, and you'll have a diagnostic skill you'll use the rest of your days.

I know what you're thinking Zippy, you're gonna actually have to study this, take it one step at a time, it ain't gonna be easy...but I assure you it'll be very worth it to you in the long run....

Voltage dropping a circuit is one of those things, it's so simple, once you "Get it," you'll do this...



REPEAT: A voltage drop occurs when current flows through an undesired resistance!
 

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Discussion Starter #10
Holy crap, I think I may need a 20 pack for that one!!! So far I have stuck to the easy stuff. Adjusted headlight, helped a little bit. The battery ends do look a bit corroded, so I'm going to clean them all up tomorrow and see what happens. Had the bike driving behind me while I was in my cage(at dusk), and didn't notice any fluctuation in the headlights. But I did get caught by a fisherman fishing on the side of the road...he was casting out and caught my car, so I was too busy laughing the rest of the ride home.....Still waiting for son to get out of work so he can show me what buttons I need on that contraption of his....
 

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You can do it Zippy.

All you have to do is turn the meter on, set it to VOLTS, and start by measuring the battery voltage.

If you can do that, you can do the entire voltage drop procedure. Easily.

It's ok if you want someone there for moral support, but YOU can do this!

Be bold!
 
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