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General Category => Maintenance => Topic started by: moparman70 on March 26, 2017, 07:13:40 PM

Title: 15 amp fuse blowing -
Post by: moparman70 on March 26, 2017, 07:13:40 PM
All -- item 43 on the schematics - ( yamaha book) is a 15 amp fuse -- It has most of the stuff on its cct -- from the tach - signals - gas gauge -- lights on instrument cluster etc.

This was blowing on my 86 --- obvisously there was a short to ground on a power wire somewhere and the trick is to find it.   I started by disconnecting the plug on the left side and under the tank but it was none of those areas.  Ultimately I had to take the right side covers - air scoop to look at the harnesses.   

I had an ohm meter on ground side of the fuse box -- good should be around 180 -- when it was shorting is was 2 or 3 ohms.   With the meter connected I wiggled the harness and found the harness in this area to be the culprit.   Specifically a white multi plug in the lower area -- a brown wire with had the insulation off and shorting --- arch marks etc.   -- corrected the wire and insulated.

So far so good ---

While this type of issue could be anywhere in the circuit -- I am posting this for others in case.
Title: Re: 15 amp fuse blowing -
Post by: red on March 26, 2017, 08:48:15 PM
Quote from: moparman70 on March 26, 2017, 07:13:40 PM
All -- item 43 on the schematics - ( yamaha book) is a 15 amp fuse -- It has most of the stuff on its cct --- obvisously there was a short to ground on a power wire somewhere and the trick is to find it.   I started by disconnecting the plug on the left side and under the tank but it was none of those areas.  Ultimately I had to take the right side covers - air scoop to look at the harnesses.  I had an ohm meter on ground side of the fuse box -- good should be around 180 -- when it was shorting is was 2 or 3 ohms.   With the meter connected I wiggled the harness and found the harness in this area to be the culprit.   Specifically a white multi plug in the lower area -- a brown wire with had the insulation off and shorting --- arch marks etc.   -- corrected the wire and insulated.  So far so good ---   While this type of issue could be anywhere in the circuit -- I am posting this for others in case.
Moparman,

NAPA and most auto parts stores will have liquid, brush-on electrical insulation in a bottle.  Two coats should do it.  They also may have spiral-wrap, which protects wires from abrasion by any nearby metal parts.  There is also a split-sheathing for the same job, which can be secured by tape or tie-wraps.  Choose the high-temperature versions of these products, for wiring near the engine.