1983 GS750E SIGNAL Fuse Blown.

[Quasimodo]

My '83 GS750E keeps blowing the SIGNAL fuse whenever I rev up the bike to about 4K--5K RPM for a short time (i.e., ~30 seconds), deactivating the instrument panel and all signal lights save for the headlight. All the other fuses are all right.

What I've done so far is replace the fuse box---the original one was a bit beat up---and the rectifier with another used one. Still the same problem.

I've also monitored the voltage output at the battery terminals and it reads 15.55, and slowly going up, at 4K--5K RPM. I know that's not right from reading the service manual and the stator papers. I'll try to follow the diagnostic detailed in the latter when I get some time, but does anybody care to hazard a guess, perhaps based on previous experiences, as to what the problem may be? Will I need to make another voluntary donation to BikeBandit for a new stator and/or rectifier?

Thanks in advance.

[SPARKSS]

Assuming your battery is ok (any cranking problems?), the problem is most likely an open regulator (or bad connections to it). This is what's allowing the voltage to continue to climb.

[Quasimodo]

Assuming your battery is ok (any cranking problems?), the problem is most likely an open regulator (or bad connections to it). This is what's allowing the voltage to continue to climb.

Thanks for responding.

The battery should be all right. It's new and I don't have any problem starting the bike up. I don't ride it often and it doesn't have any trouble starting even after a 2--3-week lay off.

Will one of those Electrex R/R units be a good choice? They're quite a bit less than OEM ones and I haven't seen any negative reviews.

Thanks again.

[Mark whiz]

With voltages over 15v, I'd definitely say that your regulator/rectifier is toast. The 1st time I had one go bad on my '85 700 it kept blowing out the headlight bulb and it was pumping out over 15volts at the time.

I have an Electrex unit on my bike right now and it is doing a good job - putting out around 14volts, give or take .5v depending on ambient temperature.

[txironhead]

Do the Honda Regulator conversion. Very easy to do, they're cheaper and designed to handle current better. I'm running one off of a CBR600 and it took me about 20 minutes to install it. It even bolted right to the factory location.

[Quasimodo]

With voltages over 15v, I'd definitely say that your regulator/rectifier is toast. The 1st time I had one go bad on my '85 700 it kept blowing out the headlight bulb and it was pumping out over 15volts at the time.

I have an Electrex unit on my bike right now and it is doing a good job - putting out around 14volts, give or take .5v depending on ambient temperature.

I'll order a new R/R. The one that's on the bike is the original, I think, and is most probably due to be replaced anyway.

Many thanks for your response.

[Quasimodo]

Do the Honda Regulator conversion. Very easy to do, they're cheaper and designed to handle current better. I'm running one off of a CBR600 and it took me about 20 minutes to install it. It even bolted right to the factory location.

I read about this and have been trying to find out exactly which part # would work on my bike. Do you happen to have that info or can point me to a place where I can find out?

Also, will it be a simple matter of cutting off the existing connector and matching wire colours?

Thanks.

[txironhead]

There are many posts on the topic in this section, do a search for "honda regulator". Many have pics and/or very detailed instructions.

There is no set "part number". People have used regulators off of CX400's, CBR600's, even '99-up GSXR. Basically you need a three-phase regulator. It will have three yellow wires, one or two red wires (positive), one or two green wires (negative), and maybe a black wire (voltage sensor). The CBR600 regulator I used had three yellow, one red, one green and one black. The posts here will tell you which factory wires go where, and what to do if your bike has the headlight loop (if your bike has the "headlight off" option, you do).

A few words of advice:

If you do decide to connect the red wire directly to the battery, make sure you install an inline fuse. Having a plastic box full of acid blow up right under your butt will ruin an afternoon ride.

Regardless of how you wire it, make a separate ground wire (length of wire with two "eyelet" connectors) to go from one of the regulator mounting bolts to a tested ground on the bike. The factory regulator is grounded to the battery box, which is insulated by non-conducting rubber grommets (doh!).

Replace all of the "bullet" connectors with quality spade connectors. Try to find some that are rated for marine use. If you can't find those, get the best quality you can find. Crimping them on is not as good as soldering them on, but if you don't solder them use heat shrink tubing to get it as watertight as possible. I've even seen people heat shrink the assembled connectors, then if they need to replace them they cut the tubing off.

MAKE SURE that all of the other grounds and connectors are as clean as possible. Emery cloth and aerosol electrical parts cleaner work great. Make sure the main ground cable is in good shape (the one bolted to the top of the engine case). Clean the terminals on your fuse box and starter solenoid. Bad connections are responsible for 95% of electric-related problems on these bikes.

This may sound like a lot of work, but it can all be done in one industrious afternoon. While you're at it, clean the connectors on your coils, that's also a problem spot on these bikes.

[Quasimodo]

txironhead:

Thanks for your suggestions and advice. I'll do some more digging and hopefully I can fix this problem soon.

Does anybody else have more suggestions about where and what to look for?

[Nessism]

Go to the For Sale forum and look up the guy selling Honda R/R's.

I've recently bought a R/R off a 2004 Honda CBR600 - paid $28 shipped off ebay. It has three yellows (for connection to the stator wires) and two pairs of red and black. No sense wire for that model bike it seems. I haven't hooked it up yet but it should be easy enough.

[Quasimodo]

Thanks for all the helpful suggestions. I ordered a new Electrex unit and put it on, and it seems to be better. Right now it's measuring about 13.2V at the battery terminals at about 4--5K RPM. However, the SIGNAL fuse is still blowing! One interesting data point: the problem occurs much more easily when the bike's hot (i.e., running for a while). Not sure what the difference is, the voltage is still about the same. But, the fuse can blow within 1 second of the bike starting if it's already hot to begin with.

I do think I've bad connectors for the R/R unit---I bought ones that I think are too big for the wire, but I decided to give them a shot anyway though I've problems crimping them properly---and probably bad connections to the harness. So, I'm going to get better ones and try them next. In the meantime, are there any more things I should look into?

Thanks again.