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While at the track last weekend our alternator went. No parts stores in the area had any x1/9 alternators, voltage regulators, etc etc. Since we had to swap an engine anyway we decided to invest some time in mounting a more common alternator.
Read more to see how we installed self (internally) regulated delco remy 10si alternator in our x1/9
Note: this is for a race car so the wiring in your street fiat may be different and especially different if it has an external voltage regulator (which you would need to remove). I can't remember how the marelli or bosch alternators that came with these cars were wired, but there is always (somewhere to the back of the car) a tie to the starter (connection to battery) and a "switched" source from the dash to excite the alternator.
From this page (found in the wiki) we found some Delco Remy Alternator part numbers:
http://www.madelectrical.com/electricaltech/delcoremy.shtml
The local NAPA had a AC-DELCO 321-39 in stock (10si 3-o-clock) : 10SI, 63 amp, at 3:00 (AC-DELCO # 321-39, Lester #7127-3) .
Note that this is one of many model numbers of this size alternator. The 12si is supposedly smaller, but we wanted a lower output alternator because we don't need that much power (we basically just need a battery charger).
Installation is straight forward but requires fabrication and is best done with the engine out of the car (but could be done in-car)
Wiring is easy, if you take a few minutes on google you can easily understand a GM 3-wire alternator.
Step 1) do your research
step 2) go to auto parts store, get the following:
a) alternator
b) electrical pigtail for the [1 2] connector on the back of the alternator
c) 12volt 1 amp (or higher) diode or 10 ohm resistor or idiot light to tie in between the "exciter" line [1] and your switch. The exciter line needs either a diode (most reliable), resistor, or warning lamp (most valuable to driver) so you can shut the car off. without this it will back-feed power and keep your coil energized. Stock cars may have this in line already but I can't comment on that.
step 3) go to home depot and get some 1-1/4" angle iron or find some other iron bits to fabricate your upper mount, your stock upper mount is useless.
step 4) - Make the lower mount:
We cut the crank pully side of the lower alternator mount off (basicaly sliced a third off) with a sawzall and a very good steel blade. We marked it by bringing the alternator to the car and eyeing up the belt alignment. This is not as good as having a bracket on both sides of the lower alternator mounting tab, but it's the best we could do and worked fine
step 5) - mount the alternator in the lower mount, snug the bolt, it should line up well and barely fit with the belt
step 6) make the upper mount, first using the existing mount as a template to drill holes in the new steel. Fabricate the bolted piece first, the alternator piece second, and the tie piece third. Tack and remove from car for final welding
step 7) wiring:
- Take the pigtail you got from the store and connect the [2] wire (red) to the [battery] ring terminal. Connect the charging wire from your starter to the [battery] ring terminal. connect the [1] wire (white) to your dash switch with the diode/resistor/idiot light in line.
step 8) start the car, test voltage (should be 14.4). turn off car, ensure it turns off. If it doesn't charge your exciter wire might not be correct (diode might be backwards, warning light burned out, etc) reverse and repeat experiment. Be sure you understand your wiring system and how everything is connected before you just test stuff... you can cause a fire!
--
Notes - lessons learned
- the hardest part and the most critical is the lower mount, this ensure you have good belt alignment. We were lucky and got it first shot.
- A "12-o-clock" alternator might be easier to wire as they are closer to the rear of the car
--
Read more to see how we installed self (internally) regulated delco remy 10si alternator in our x1/9
Note: this is for a race car so the wiring in your street fiat may be different and especially different if it has an external voltage regulator (which you would need to remove). I can't remember how the marelli or bosch alternators that came with these cars were wired, but there is always (somewhere to the back of the car) a tie to the starter (connection to battery) and a "switched" source from the dash to excite the alternator.
From this page (found in the wiki) we found some Delco Remy Alternator part numbers:
http://www.madelectrical.com/electricaltech/delcoremy.shtml
The local NAPA had a AC-DELCO 321-39 in stock (10si 3-o-clock) : 10SI, 63 amp, at 3:00 (AC-DELCO # 321-39, Lester #7127-3) .
Note that this is one of many model numbers of this size alternator. The 12si is supposedly smaller, but we wanted a lower output alternator because we don't need that much power (we basically just need a battery charger).
Installation is straight forward but requires fabrication and is best done with the engine out of the car (but could be done in-car)
Wiring is easy, if you take a few minutes on google you can easily understand a GM 3-wire alternator.
Step 1) do your research
step 2) go to auto parts store, get the following:
a) alternator
b) electrical pigtail for the [1 2] connector on the back of the alternator
c) 12volt 1 amp (or higher) diode or 10 ohm resistor or idiot light to tie in between the "exciter" line [1] and your switch. The exciter line needs either a diode (most reliable), resistor, or warning lamp (most valuable to driver) so you can shut the car off. without this it will back-feed power and keep your coil energized. Stock cars may have this in line already but I can't comment on that.
step 3) go to home depot and get some 1-1/4" angle iron or find some other iron bits to fabricate your upper mount, your stock upper mount is useless.
step 4) - Make the lower mount:
We cut the crank pully side of the lower alternator mount off (basicaly sliced a third off) with a sawzall and a very good steel blade. We marked it by bringing the alternator to the car and eyeing up the belt alignment. This is not as good as having a bracket on both sides of the lower alternator mounting tab, but it's the best we could do and worked fine
step 5) - mount the alternator in the lower mount, snug the bolt, it should line up well and barely fit with the belt
step 6) make the upper mount, first using the existing mount as a template to drill holes in the new steel. Fabricate the bolted piece first, the alternator piece second, and the tie piece third. Tack and remove from car for final welding
step 7) wiring:
- Take the pigtail you got from the store and connect the [2] wire (red) to the [battery] ring terminal. Connect the charging wire from your starter to the [battery] ring terminal. connect the [1] wire (white) to your dash switch with the diode/resistor/idiot light in line.
step 8) start the car, test voltage (should be 14.4). turn off car, ensure it turns off. If it doesn't charge your exciter wire might not be correct (diode might be backwards, warning light burned out, etc) reverse and repeat experiment. Be sure you understand your wiring system and how everything is connected before you just test stuff... you can cause a fire!
--
Notes - lessons learned
- the hardest part and the most critical is the lower mount, this ensure you have good belt alignment. We were lucky and got it first shot.
- A "12-o-clock" alternator might be easier to wire as they are closer to the rear of the car
--
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