• Welcome to the Two Wheeled Texans community! Feel free to hang out and lurk as long as you like. However, we would like to encourage you to register so that you can join the community and use the numerous features on the site. After registering, don't forget to post up an introduction!

Rectifier heats up even with key turned off

Forums New posts
P

paulpah

0
Joined
May 23, 2017
Messages
45
Reaction score
5
Location
Frisco, TX
I bought my 2004 Aprilia Futura with the connectors from the rectifier to the bike's circuit soldered.

A friend and I cut the soldered portion out and installed connectors to them. after 1 week of riding around with the bike completely fine, i rode home from work 2 days ago with an extremely strong burnt plastic smell. The connector connected to the rectifier was the culprit and my battery was kaput as a result as well.

After replacing the battery, even with the key off, the burnt smell reappears from that particular connector and the rectifier gets hot in under 2 minutes, i immediately disconnected the battery and now i'm clueless as to why this happens even with the key not inserted into the ignition.

Any clues here?
 
The rectifier has an internal short to ground. The shunt to ground is stuck. There is no fuse to trip from the rectifier to the battery, so everything just keeps heating up.
 
RollingJ said:
The rectifier has an internal short to ground. The shunt to ground is stuck. There is no fuse to trip from the rectifier to the battery, so everything just keeps heating up.
Click to expand...
So he needs to replace it correct? Or hit it with a hammer????
 
Replace the rectifier.

For goggles you could disconnect the rectifier connector and check for resistance (rectifier side of connector) from the pin leading to the battery to the pin leading to ground (or the case of the rectifier).

There should not be continuity, and resistance becomes a load and generates your heat.

I'm sure than made sense.
 
Maybe also look to see why the R/R is in circuit with key OFF?? Soldered wiring indicates a problem not addressed. I like RollingJ's thoughts. AND, why no main fuse[aren't they 30-50 Amps?]?
 
wanabeguru said:
Maybe also look to see why the R/R is in circuit with key OFF?? Soldered wiring indicates a problem not addressed. I like RollingJ's thoughts. AND, why no main fuse[aren't they 30-50 Amps?]?
Click to expand...
The fuses are fine at 30amps i'm curious to, why is it heating up with the key off.
 
POssibly the heat damage has shorted the regulator to ground? Most Futura owners had issues with high resistance connections on the regulator, lots of them out there with a melted fairing over the regulator/regulator connector. Go up on the AF1 forums and research it. The issue can be fixed, I believe there are (were) kits to fix this.

P.S. There is a Futura section of the forum, good information if you need it. Click HERE
 
paulpah said:
The fuses are fine at 30amps i'm curious to, why is it heating up with the key off.
Click to expand...
Sounds like current flow when key is off. Possible high resistance short maybe to ground. Loose connections heat up as well as high resistance shorts or grounds and possibly not blow 30 amp fuse. Loose electrical connection = heat someone was addressing issue with solder joints. Keep after it you will solve the mystery. I would pull negative battery cable when I park it and see if it still heats up, from internal residual temperature, They do have cooling fins.
 
The original slip on connector probably melted due to high current draw or a high resistance, it sounds like you inherited a problem in the electrical system. A high resistance condition will generate heat, plastic hates heat. Hope you can sort this out, that is a sweet ride!!
 
paulpah said:
The fuses are fine at 30amps i'm curious to, why is it heating up with the key off.
Click to expand...
You said fuses are fine at 30 Amps. My limited knowledge of your bikes electrics makes me wonder why there is more than ONE 30 Amp circuit. My bike has ONLY ONE HIGH AMP FUSE. All the rest are 15 or less. If you have multiple 30 Amp fuses that don't belong a PO was covering the problem by overfusing. So, can you use a meter to read current[placed in series with circuit under test]? Meter must have a scale high enough so you don't damage it[i'm gonna guess 20 0r 30 Amp range. Connect meter to EACH circuit on bike noting readings[to be matched against wiring diagram or at least fuse in circuit[which may be wrong value]]. If you have a digital meter it won't matter which way you connect it as you are looking for the NUMBERS it shows. I'm thinking you will find a circuit reading way higher than expected[the culprit]. You may have to follow wires as there could be scrapped insulation causing a partial short. Hope this helps. If all else fails, i can get you a great deal on my patented smoke re-injection kit! Good luck, stay in touch. BTW, stay away from reading main battery cable current as most meters can't read that high.
 
wanabeguru said:
You said fuses are fine at 30 Amps. My limited knowledge of your bikes electrics makes me wonder why there is more than ONE 30 Amp circuit. My bike has ONLY ONE HIGH AMP FUSE. All the rest are 15 or less. If you have multiple 30 Amp fuses that don't belong a PO was covering the problem by overfusing. So, can you use a meter to read current[placed in series with circuit under test]? Meter must have a scale high enough so you don't damage it[i'm gonna guess 20 0r 30 Amp range. Connect meter to EACH circuit on bike noting readings[to be matched against wiring diagram or at least fuse in circuit[which may be wrong value]]. If you have a digital meter it won't matter which way you connect it as you are looking for the NUMBERS it shows. I'm thinking you will find a circuit reading way higher than expected[the culprit]. You may have to follow wires as there could be scrapped insulation causing a partial short. Hope this helps. If all else fails, i can get you a great deal on my patented smoke re-injection kit! Good luck, stay in touch. BTW, stay away from reading main battery cable current as most meters can't read that high.
Click to expand...

The Italians always need to do things differently, there are 2 sets of wires coming out of the rectifier(2 + and 2 -) hence the 2 fuses, on the wiring diagram these 2 are shorted. shortly after making their way past the connectors. As to why Aprilia didn't do away with just 1 big fat cable to lower resistance is anyone's guess.

But the culprit has been a shorted rectifier, replacing it has solved the issue(not to jinx it). Forza Italia.
 
You must log in or register to reply here.
Back
Top