Important: Improvements on Saturn Alternator Swap

[lasthope05]

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Are you sure you ground the block correctly? Part A needs to be ground down completely to match part B.

 

[RipperXX]

Well son of a bi*** that would have been nice to know! In the only thread I found from several years ago on a 1g, that picture wasn't available, most weren't any longer actually. Thank you for posting that.

 

[DSM98GSX]

Ripper,

After years of fabbing and modifying, I can tell you a sharpie is your best friend! So that I knew where to clearance, I literally colored the area's I thought were hitting and got it mounted as best as possible then moved it up and down a bit to "etch" the sharpie area. This told me exactly what was hitting. I had to grind down the "A" part quite a bit to get the movement.

As for the 1 wire, it's definitely worth it. You literally start the car and it starts charging. No relays or anything needed. Make sure you check out the turnbuckle info I posted on page 17. Helps a ton and looks clean! Good luck

 

[RipperXX]

Never mind

 

[RipperXX]

Never mind. I just figured it out. What do guys with the 1 wire setup do with the factory plug?

Installed! Now let's hope the factory wiring that's never been used in the last 14 years actually works! Since the dip shit previous owner cut the factory wires I had to lengthen them. I used 8 gauge wire and crimped on terminals like you see on the charging post but smaller, and used a brass screw and nut to secure them together, then head shrinked the connection. Well all of them actually and covered connections I with wire loom.

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I need to figure out a way to shield it and the wiring from the exhaust heat...

 

[boostdawd]

I used hard wire loom and heat reflective sleeving.

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[DSM98GSX]

I don't have a picture of it but since I have my battery relocated to the trunk, I rewired from the alternator back. I used (I think) 1/0 welding wire. Probably a bit overkill but the outer protective coating in the engine bay is what I was considering. When you run any kind of wire next to a heat source, it's a good idea to protect said wire from the extreme heat that melts the coating. Looking at the wire you have, it probably doesn't have the highest heat rating so I would definitely consider doing a heat reflective sheath at a minimum. As for the stock plug, I no longer have that one installed on the car so cant help you there.

 

[RipperXX]

Yeah im going to look for some heat reflective sheathing for the wiring. I have reflective tape from DEI I'm tempted to clean the back of the alternator with acetone and try to stick some on it, and just cut out the vent holes with a razor...wish I had done that before installing it the last time. Oh well.... I was just happy I finally got the bastard on .

 

[RipperXX]

Well, got it installed. Went to start the car, turned over..and over...and over huh. Not even trying to fire. So I look and see I tucked the fuel pump wire out of the way and didn't remember to connect it. Ooops yeah that would do it. So I connect it, car fires up on the 2nd try, I hop out and grab my multi-meter...12.08volts hmmm why aren't you charging!? Shut the car off.. start probing the charging circuit...wait how can there not be continuity from the fuse, alternator side to the positive post...start following wire...Ooops again I swore I connected that... okay 3rd times a charm.

Start the car, check battery voltage at the battery, 12.5, 13, 13.5, 13.8 wow! This thing is a beast! 14, 14.15, 14.28, 14.32, 14.37, 14.4, 14.44, .46, .48, .50, .52, .53, .54, stabilized at 14.55v. All in under probably 45 seconds on an old tired battery, damn color me impressed, and at idle!

I was going to take it for a quick spin but I'm messing with the seats and the lap belts aren't installed so that will have to wait. But thank you for those who helped with advice on this! Now I just need to wrap up that seat project and get a piece of heat reflective sheathing on those charging wires and see if I won the lottery on the alternator charging above 6200rpm as it sounds like some don't like high rpm.

Curious to see how it affects AFR as well.

 

[boostdawd]

Good stuff man! Definately a worth while mod.

 

[SasaniFab]

Well, got it installed. Went to start the car, turned over..and over...and over huh. Not even trying to fire. So I look and see I tucked the fuel pump wire out of the way and didn't remember to connect it. Ooops yeah that would do it. So I connect it, car fires up on the 2nd try, I hop out and grab my multi-meter...12.08volts hmmm why aren't you charging!? Shut the car off.. start probing the charging circuit...wait how can there not be continuity from the fuse, alternator side to the positive post...start following wire...Ooops again I swore I connected that... okay 3rd times a charm.

Start the car, check battery voltage at the battery, 12.5, 13, 13.5, 13.8 wow! This thing is a beast! 14, 14.15, 14.28, 14.32, 14.37, 14.4, 14.44, .46, .48, .50, .52, .53, .54, stabilized at 14.55v. All in under probably 45 seconds on an old tired battery, damn color me impressed, and at idle!

I was going to take it for a quick spin but I'm messing with the seats and the lap belts aren't installed so that will have to wait. But thank you for those who helped with advice on this! Now I just need to wrap up that seat project and get a piece of heat reflective sheathing on those charging wires and see if I won the lottery on the alternator charging above 6200rpm as it sounds like some don't like high rpm.

Curious to see how it affects AFR as well.

What I still don't understand is when I had the Saturn installed dsmlink was reporting voltage in the 13s, when I checked with a multimeter it was in the 14s? I ended up going back to the oem alternator? How are you guys wiring it in?

 

[RipperXX]

I opted for the 105amp modified 1 wire setup. It's not optimal, but it's by far the easiest, and so far it's pumping out good voltage up to nearly redline. I'd have to check a log but I think it does fall to 13.8 later in the pull and stabilizes there until redline but that's still way better than before.

I only have a small radio, original sized and number of speakers and the engine & associated systems to power. Considering the original was what, 65amp's I figured the 105 was plenty, and it seems to be enough.

 

[DSM98GSX]

I opted for the 1 wire 200 Amp as well. Made it extremely easy to do considering my wire tuck. This is by far the best alternator I've had in the Eclipse. My main concern was the swap to EHPS (Electro-Hydro Power Steering) system was going to draw too much in a lower amperage setup near idle and lower RPM (which is where PS is used the most). Plus a 1 wire setup, and I don't have to worry about swapping all kinds of wires around to make it work with a new exciter...Yes please.

 

[AndrexZ]

Hey guys just finished up my Saturn alternator swap. And it's awesome!

If someone could give me a little info on this situation....I bought a brand new 105 amp from advance auto. Install was easy wiring was alright. I ran 2 new power wires to the fuse block then another 8 to the battery. I also ran 8 gauge ground to the battery. I ran the S terminl with a 12 gauge wire to my radio illumination wire. With I am seeing 14.7 at 900 rpm idle and a 15.3 volt charge at around 1500 rpm. Is that really bad? I unhooked the S wire and get a steady 14.3-14.8 from idle to 2000 rpm. I also noticed it seems not to stutter, as bad with no S wire hooked up. I was running the gm maf-t without a chipped ECU so I could only get o about 2k before it started running like sh**.

Glenn I was wondering if I could get your input on the 15.3 volt charge if thats ok thanks!

Hello,
Were you able to find out if 15.3v was dangerous during a cold start, did it lower once engine warmed up?

I was able to find a source for my "S wire", I connected it to the 12v wire that feeds my gauges that was about 12.8v (I think it is too low), Fuse box was receiving 13.8V, alternator was generating 13.9v.

Once I connected the S Wire, alternator generated 15.1v (measured at the alternator positive bolt).

I guess it would have lowered once the car reaches its normal temperature but I preferred to disconnect it since I was not sure if that voltage was safe.

Can anyone tell me if that is a safe voltage for a cold start?

Note: I also tried connecting the S wire to the positive post at the battery (which is in the trunk) but I didn't notice so much difference..

 

[rarest_90_DsM]

Hello,
Were you able to find out if 15.3v was dangerous during a cold start, did it lower once engine warmed up?

I was able to find a source for my "S wire", I connected it to the 12v wire that feeds my gauges that was about 12.8v (I think it is too low), Fuse box was receiving 13.8V, alternator was generating 13.9v.

Once I connected the S Wire, alternator generated 15.1v (measured at the alternator positive bolt).

I guess it would have lowered once the car reaches its normal temperature but I preferred to disconnect it since I was not sure if that voltage was safe.

Can anyone tell me if that is a safe voltage for a cold start?

Note: I also tried connecting the S wire to the positive post at the battery (which is in the trunk) but I didn't notice so much difference..

Did you ever get this solved? Are you getting 15v at the battery as well?
I installed the Saturn alt on my 90 eclipse with the jayracing relocation kit. Lots of good write ups for a 2g and 1g but conflicting wiring diagrams for a 1g. I ended up wiring the F (black wire on Saturn harness) to a switched 12v in the engine bay (top right wire on windshield wiper motor) and the s wire (red 12gauge wire Saturn harness) to the battery fuse, at the under hood fuse box (not the alternator fuse) . Then ran a ground wire from the battery directly to the case on Saturn alternator. Heat shrink up my stock connections and tucked them into the harness. Car runs amazing changed the whole car. 15v at the alt cable 14s at the battery. No draining the battery with the key off. Hope this helps anyone trying to do this on a 1g.

 

[motomattx]

I just ran the output to the battery junction block and the one thin wire from the alternator to the same junction and it does perfect.

 

[AndrexZ]

Did you ever get this solved? Are you getting 15v at the battery as well?
I installed the Saturn alt on my 90 eclipse with the jayracing relocation kit. Lots of good write ups for a 2g and 1g but conflicting wiring diagrams for a 1g. I ended up wiring the F (black wire on Saturn harness) to a switched 12v in the engine bay (top right wire on windshield wiper motor) and the s wire (red 12gauge wire Saturn harness) to the battery fuse, at the under hood fuse box (not the alternator fuse) . Then ran a ground wire from the battery directly to the case on Saturn alternator. Heat shrink up my stock connections and tucked them into the harness. Car runs amazing changed the whole car. 15v at the alt cable 14s at the battery. No draining the battery with the key off. Hope this helps anyone trying to do this on a 1g.

Since I wasn't able to find out if higher voltage than 15v was safe enough, I decided to conntect the S wire to a higher possitive (instead of using the 12.8v line I found another one of 13.2v) that way the Alt regulator will not compensate that much voltage, (now it generates 14,5v in a cold start and 14.0v in a regular operation).

 

[curt-s]

Finally got around to doing this. Couldn't find the pigtail locally with sense and the one I've been running only has L and F, but I did find a GM headlamp connector pigtail and used the larger terminal from that to alter mine and add the S(ense). Great thing is it comes with two the same size so if you accidentally mess it up, you have another.

Cold start, like above, 14.5 and then with headlamps it ran between 13.8 and 14.1 consistently even at idle. Beautiful. I did have a couple drops to 13.5 or even one to 13.3 but it was very brief.

15C ambient temperature today and I was running without the lower exhaust shield because I think it's been contributing to my phantom knock, so the alt likely saw some increased temperatures but it still performed great.
@turboglenn you're magnificent

 

[turboglenn]

that's great to hear I'm glad to see this thread still helping people, I seartched it for my own information today as I'm having intermittent output issues with my saturn alt on my 1g

 

[o0GuitarKid0o]

Hey heres somthing to add! You can use the 1998-2002 saturn alternators . The one I got was a 1.9 liter motor but was exactly the same as the I think 3.1 liter. So if your in the wrecker looking and cant find any 90s ones grab a 2000! Just double check it before you buy it. You'll notice theres no fan blades to worry about for your tensioner

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This is the one in my car and as of right now I left out the feild circuit(F), it was causing a humming sound as it was a constant 12v signal going to the alternator and not switched. Next year I'll wire it up .

35$ all said and done at the wrecker as I couldnt find a dsm alternator or 1996 saturn alternator with the fan.

 

[motomattx]

Good info!

 

[curt-s]

I have been wondering if those would work but wasnt certain due to design change. Your belt sits neutrally aligned? Awesome.
I am at a solid 13.8 after heatsoaking and only drop to 13.5 at higher revs but having cheaper alternatives since these are impossible to find in this city is frickin fantastic.
Its just a shame these saturns are disappearing and theyre such a PITA to extract an alt from..

 

[motomattx]

They ARE a pita to pull the alternator from, what kind of engineer located that thing half way down the engine up against the inner fenders anyway?

 

[o0GuitarKid0o]

I have been wondering if those would work but wasnt certain due to design change. Your belt sits neutrally aligned? Awesome.
I am at a solid 13.8 after heatsoaking and only drop to 13.5 at higher revs but having cheaper alternatives since these are impossible to find in this city is frickin fantastic.
Its just a shame these saturns are disappearing and theyre such a PITA to extract an alt from..

Yup sits pretty much the exact same as the OEM alternator . The Tensioner is the trickiest part tbh . I used the saturn bolt for the block .
And yup couldn't find a mid 90s one at all at bucks. And litteraly I spent more time at bucks removing it due to the crappy spot behind the block. Only took an hour to throw on I made a temporary tensioner bracket as I didnr want to remove my power steering pully .

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I added a second bolt to secure it but once I have time I'll bend a steel bracket and do it properly

 

[o0GuitarKid0o]

Made my temporary tensioner bracket smaller and moved the belt closest to the driver side fender 14.2 volts at idle and lowest so far is 13.8 gotta getter hot and check out my logs

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