Charging System and Power Distribution (Alternator Burning Potential Fix)
01-05-2016, 12:27 PM
#1
Racer
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Charging System and Power Distribution (Alternator Burning Potential Fix)
Hi
My 1991 has been having alternator trouble over the past few years. I have gone through about 10 alternators and I finally think I have found the problem. It seems during my conversion to right hand drive, the charge wire going from the alternator to the junction block was split, one going to the battery, the other going to the junction block. The charge wire at the junction block was very hard and darkened. From the wiring diagram I see that another wire on fusible link B goes from the junction block to the alternator regulator terminal "S"
My issue was the voltage read at the regulator terminal "S" was always just over a volt lower than the voltage read at the battery. Over the years I added extra grounds, extra thick charging wire directly to the battery, but never paid attention to the wire that goes from the battery to the junction block connection. My alternator consistently wanted to put out over 14 volts without any load and a hot engine, causing itself to burn up.
Before I go replacing more wires I wanted to see if anyone had any insight into why in the attached power distribution from FSM shows the alternator output charge wire going directly to the junction block, and then a smaller gauge wire from the junction block to the battery, rather than going to the battery directly.
If there was a good reason to have the main charging wire go straight to the junction block rather than the battery, I am happy to keep this set up and replace the wiring with thicker gauge. Does anyone know about this?
If I were to reverse the order and keep my thick gauge charging wire to the battery directly, and then add another wire to the junction block, could this cause further issues later on?
I have yet to test the fusible link B to see if that also has high resistance leading to the voltage drop reading at the regulator. I will try this week and post back.
Cheers!
My 1991 has been having alternator trouble over the past few years. I have gone through about 10 alternators and I finally think I have found the problem. It seems during my conversion to right hand drive, the charge wire going from the alternator to the junction block was split, one going to the battery, the other going to the junction block. The charge wire at the junction block was very hard and darkened. From the wiring diagram I see that another wire on fusible link B goes from the junction block to the alternator regulator terminal "S"
My issue was the voltage read at the regulator terminal "S" was always just over a volt lower than the voltage read at the battery. Over the years I added extra grounds, extra thick charging wire directly to the battery, but never paid attention to the wire that goes from the battery to the junction block connection. My alternator consistently wanted to put out over 14 volts without any load and a hot engine, causing itself to burn up.
Before I go replacing more wires I wanted to see if anyone had any insight into why in the attached power distribution from FSM shows the alternator output charge wire going directly to the junction block, and then a smaller gauge wire from the junction block to the battery, rather than going to the battery directly.
If there was a good reason to have the main charging wire go straight to the junction block rather than the battery, I am happy to keep this set up and replace the wiring with thicker gauge. Does anyone know about this?
If I were to reverse the order and keep my thick gauge charging wire to the battery directly, and then add another wire to the junction block, could this cause further issues later on?
I have yet to test the fusible link B to see if that also has high resistance leading to the voltage drop reading at the regulator. I will try this week and post back.
Cheers!
01-05-2016, 02:36 PM
#2
I would think constructing a tailored positive cable routed to a MAXI FUSED JUNCTION BLOCK with the + sized cable, a pigtail of the same metric used now to the factory JUMP BLOCK and the + sized cable continuing to the alternator. Maybe consider +2 from the battery to the MAXI, +1 for the pig-tail and of course the +2 from MAXI to the alternator with a 120AMP MAXI block used.
Look at some of the Cooper/Bussman product, maybe the HI-AMP circuit breaker types OR just a BOLT IN HI AMP FUSE
http://www1.cooperbussmann.com/pdf/f...a4236a26bf.pdf
Of course you need to do the tailored post connection for these and the starter cable also. The S - terminal could likely remain the same routed to the MAXI I believe or +1 maybe. This is how I've done this in the past, a fellow told me what he wanted and I got him what he asked for paying little attention to his sketches, take FSM wiring to an AUDIO/electronics shop there and ask, BUT THEN asking maybe one or two more for an opinion.
Being a RHD conversion I don't know why maybe the factory JUMP BLOCK just wasn't replaced aside from the rest of the circuits likely functioned well from there.
Look at some of the Cooper/Bussman product, maybe the HI-AMP circuit breaker types OR just a BOLT IN HI AMP FUSE
http://www1.cooperbussmann.com/pdf/f...a4236a26bf.pdf
Of course you need to do the tailored post connection for these and the starter cable also. The S - terminal could likely remain the same routed to the MAXI I believe or +1 maybe. This is how I've done this in the past, a fellow told me what he wanted and I got him what he asked for paying little attention to his sketches, take FSM wiring to an AUDIO/electronics shop there and ask, BUT THEN asking maybe one or two more for an opinion.
Being a RHD conversion I don't know why maybe the factory JUMP BLOCK just wasn't replaced aside from the rest of the circuits likely functioned well from there.
Last edited by WVZR-1; 01-05-2016 at 02:48 PM.
