electric prob.

[bigb9582]

well tonight i had to ride my bike home in the rain. when i parked it, before the rain it was fine. after geting down poured on, i went to ride home in the rain and now any time the rpms drop below 1500 the lights dimm bad or go off and my tach stops working. anything above 1500 rpms everything gos back to normal.
none of this happened before the rain, so any help as what to look for.

[bigb9582]

oh forgot. its a 79 standard.

[TopCatGr58]

Hey there BigB,

Welcome!! You might want to EDIT your profile to include the information about the MODEL, you put the year, but there are differences that can affect the advice we give!

Okay, rain isn't pure water, and has impurities in it which can make it a fair CONDUCTOR!!!

Your headlight turning off as well as your TACH points to your charging system! However, it could be the VOLT Reg/Rect that sits under your tank! Pull the tank and pull the reg/rect, clean the frame contacts...the GROUNDS for it, and also pull apart the PLUGS, check for corrosion, clean/dielectric grease them. Same for the plugs behind the FUSE BLOCK, 3 large white plugs for the ALT, they can corrode, and IF they get too much resistance, can actually melt or burn thru/away!

In other words, check the plugs and fuses for the charging system, as well as most of your other plugs/connectors, clean and apply dielectric grease to protect from further corrosion and water shorting!!
T.C.

[bigb9582]

ok i will check the connections. i had no prob. till my bike sat out in the rain.
one question tho. lets say if the water is shorting out the charging system how comes it gos away when i give it more rpms? wouldnt the water short it out regardless of the rpms? when it comes to some electric stuff i get confused.

thanx for any help.

[TopCatGr58]

Well, corrosion and resistance is more of what I'm expecting you to find, than just shorting out. At low rpms, the reg/rect and charging system may not be putting out enough to overcome the resistance of corrosion in some of the plugs, and when you finally rev it up, it then creates enough voltage/pressure to overcome the corrosion resistance and flow!? The water may have cause a small short in the reg/rect plugs so that at low rpms it isn't sensing the voltage properly and so not properly triggering the field coil or such to put out!? I'm no electrical guru, that's the status of the B'day boy today, RANDY!!!

Good Luck! T.C.

[bigb9582]

cool thanx for the info

[randy]

TC, I couldn't have said it better!

There are three things that afflict these old electrical systems:

corrosion, corrosion and corrosion

One more thing, bigb9582m how old is your battery? your symptoms could also describe a worn out battery that won't charge.

[bigb9582]

battery is about 2 months old

[bigb9582]

cleaned everything, went to salvage yard and got 2 regulaters. nothing, got no headlight now, but tach works, im stumped

[bigb9582]

ok now my light works, tach still dies under 1500rpm.
BUT now when my bike is running the MAIN fuse in the fuse block gets so hot it burns me, the fuse wont blow and its a 30 amp fuse. i dont know what to do now. i guess tomarrow im gonna have to start tearing apart my wire harness to see if there is a short someware.

[TopCatGr58]

Hey Big,

The tach reads signals/pulses from 1 of the 3 legs of the charging circuit.

There are diagnostic tests you can do for the REG/RECT. It grounds to the FRAME, did you clean the mounting surfaces and bolts that secure it to the frame? There are also diagnostic tests for the ALT/field coils as well. See the tech tips, hope you have a MANUAL!?

The Reg/Rects are known to go bad just due to the quality of the parts used. There is a Member on here that makes a replacement high performance unit for them, look in the Parts For Sale forum, the STICKY thread, Geezer's Reg/Rect!

But, yes, check the harness, look for wires chaffed or contacting the frame with bare wires, etc.! Also check the contacts in the MAIN SWITCH, you can take it OFF and take it apart to be sure the wires are still attached, have been known to come unsoldered! Just remove or disconnect the battery before doing so!
T.C.

[trapper_492001]

Corrosion can cause and will cause heat. The best thing you can do is pull every conecter you find and clean and use dieltric grease. I had problems with my head light. Found bad ground and could see some corrosion on another conecter the more I checked the more I found. Now no problem in the rain.

Trapper

[bigb9582]

well i bought 2 spare regulaters. i swapped one out, i left the switch on it got really hot and started smoking. i took it off and put another one on. i havent had any prob with this one yet but now the fuse gets realy hot.

no i dont have a book, which sux.

i will recheck the alt and reg again tomarow. i did check them and they were a little different then the values listed on the tech tips, but i cant remember what they were now.

not to sound like a goob but whats the "MAIN SWITCH" are u talking about?

[TopCatGr58]

The Main Switch, the KEY SWITCH at the handlebars, can be removed and taken apart to check!
T.C.

[bigb9582]

ooo ok i never thought of it as the main switch. haha
ill check it to.