1985 GS550ES Fuese Block Getting Warm

[Guest]

I have a 85' GS550ES and I have voltage drop issues, no surprise here. But I found that the fuse block is getting warm. I tried to disassemble the fuse block but I couldn't get it to separate. I have battery voltage input to the block but all my outputs are .5v less, not a big deal but I have close to 2 volts drop at my coils. I cleaned the kill switch contacts and got it to 1.75v drop at the coils.

What else should I clean? does it run up to the ignition as well?


I could do a coil relay mod but I would rather keep original.

Any input on what I should do next?

[Curtie94]

I was checking key on engine off. So I started it and found that im above 12.5v at idle so I think I have sufficient voltage at the coils. I was just chasing my own tail.

That might also explain the fuse block since it was powering the coils.

[fbody_mike]

Mine gets warm too. I disconnected the connector at the bottom and reconnected it and it seems to get warm still but not as warm. I know I have around 1 volt drop from the battery to the ignition. I didn't try reseating the fuses but that might help some too.

[cowboyup3371]

You really should go through and clean all connections to include the back of the fuse block.

[posplayr]

https://www.thegsresources.com/_forum/showthread.php?237763-Recommended-Products-for-Preparing-Electrical-Connenctions&highlight=contact+cleaner

[Redman]

I dont know if the 85 ES fuse block is same as my 82, but if it is, yah, there are connectors internal to the fuse block. So are opportunitys for bad connections inside the fuse block. I dont specifically recall how to get it apart, other than by prying on the back to seperate from the body.
Be prepaired internal parts to fall all over the place.
I think I got mine apart, and then just replace it with a salvage unit off ebay. .... and then got another extra one also.


I would also suspect the connections where the wiring harness pluggs in.

I would suspect that some if not most all the voltage drop is at the ignition swtich.
Check voltage at the small red wire (from the main fuse) and check voltage at the orange wire (from ign swtich to the head-ignition-signal fuse). If a difference tat would most likley be the ignition swtich. Check voltage at the same wires on back of ignition swtich to verify.

[Curtie94]

I have about 1v of drop from the battery to my coils. The fuse box looks just like the one pictured.

I went through and cleaned all the connections I could get to easily. I had to repair some wiring on the ignition switch due to a break. The power wire from the ignition switch to the tail light was broken. I didnt see much of a voltage drop through the ignition switch, I believe it was .3v.

I am going to run the bike and check to see if the fuse block gets warm while running or if the coils being powered all the time with the key on was the cause.

Thanks.

[Corvette95]

having similar issues with 86. Did you ever solve this?

[Brendan W]

having similar issues with 86. Did you ever solve this?

Open and clean the ign switch the kill switch and the fusebox and every plug and connector in between particularly the fusebox rat tail plug.
Individually they may not be a lot but six or seven components add up quickly.
Check the fuses with the bike running. You may find one end of a fuse is a lot warmer than the other end.
This can be a defect in the fuse, presume you have glass, where the solder inside the cap has cracked.
Now start thinking about the grounding side. Bad grounds will take voltage as well.
It's worth looking at the info on here about single point grounding, SPG.

[Steve]

Anywhere you have a connector in the wiring harness, you have three interfaces, or connections. You have one where the wire is crimped into a terminal, another where that terminal touches another terminal, and a third where that terminal is crimped onto the next wire. Every one of those interfaces is a potential for corrosion. Corrosion will resist current flow, and that translates as heat and voltage loss.

Now trace the current path between the battery and the coils. Remember that every time you see "connector", you have 3 potential sources of corrosion.

Battery
Connector
Fusebox
Main fuse
Connector
Main harness to the front
Connector
Ignition switch
Connector
Main harness back to fusebox
Connector
Ignition fuse
Connector
Main harness to front
Connector
Sub harness to right handlebar
Kill switch
Sub harness back toward main harness
Connector
Sub harness toward coil
Connector
Coil
Connector
Wiring toward ignitor
Connector
Ignitor
Connector
Wiring to ground.

If you only have a one-volt loss at the coils, ...

.