Spyder New DSM P0300

[itty Bitty “Spyder”]

What’s up! I finally found another DSM.
What are some of the things I should check out?
What maintenance and repairs do I need for daily driving?

Thanks

 

[ItsTwan309]

I find it interesting that the wiseman Made a comment about my wiring diagnostic skills but was not able to tell me how to accurately do a pinpoint test.

he wants you to look up how to do the pinout. He would rather you learn how to do it than you to misunderstand something he wrote.
Its better to give the answer of what to check and let you do the research, if you are given all the answers you wont grow in knowledge

 

[steve]

I find it interesting that the wiseman made a comment about my wiring diagnostic skills but was not able to tell me how to accurately do a pinpoint test.

Which wiseman do you refer too? Do you somehow think people are obligated to hold your hand and respond every few mins?
AI's are free but provide dribble and nonsense as I would have hoped you've figured out by now, people on the other hand have demands on their expertise and time and have to make decisions on where to spend both. It's up to you to make sure they feel like it's well spent.

I spent my available time this morning cleaning up 3 pages of this thread in an attempt to make it readable and figure out what was going on. I can't say how much time Paul had today and if he feels like it was put to good use.

 

[1990TSIAWDTALON]

Good luck!
Maintenance of all belts and hoses would be the first and most important things to do. Any mods will come after that has all been freshened up.

 

[ItsTwan309]

It looks like the fun is over thank you so much god bless.

We want you to grown and learn. This community is excellent and this forum is the best place for information.
No one insulted you or your intelligence in any of the comments. I will say if you are set to be a mechanic, you will need thicker skin because the pep talk you got today is peanuts to what will happen in a Ford shop or any other

Try all suggested tips and report back with the news. give the info you received and ask what you should check next. not how, or where the items is. that part is up to you. The information can be found within this forum (though it can be hard to search) or google, which will take you to good threads and or youtube videos.

 

[steve]

Seriously, you can edit posts rather than make 5 in 30 mins. Or you can wait until you have your thoughts together and make one post.

If this is a medical issue I feel for you but if not ...

 

[1990TSIAWDTALON]

Thanks Steve, this forum exists because people are willing to help those that are willing to help themselves and learn. We are all still here, if you need something that you can't find or figure out.
Marty

 

[pauleyman]

I think ive been called out here. Thats fine. I'll help where I can but generally I'm not going to explain very very basic things on this forum. It isn't the place for it typically. I expect somebody to know what electrical continuity is, right tighty lefty loosey, physical inspection vs visual inspection. Etc. Now if youre truly destitute, like stranded somewhere and convey you dont even know what phillips vs flat is, we can work within those boundaries. That is not typically the case of somebody buying a high performance car they intend to modify and worse one that is a minimum of 27 years old. One must have to learn how to help themselves to some degree. We're here for everything else.

 

[1990TSIAWDTALON]

Thanks Paul. You know I appreciate it and you!
We help when we can. You have to be committed to these cars and do your homework if needed. The community here is A++++.
Thank you to all the members!
Marty

 

[itty Bitty “Spyder”]

I went out and did a voltage drop test of the alternator b+ because I realized I had only done an available voltage reading.what are the spec.’s 0.2 to 0.4?

My reading went up as high as 0.55 at operating temperature with all loads on.

Step-by-Step Pinpoint Tests
1. Initial Battery Check

Always ensure your battery is fully charged (around 12.6V) before testing the alternator, as a severely dead battery will skew test results. [1]

• Connect your multimeter to the battery terminals.
• A reading <12.2V means you should charge the battery before testing further. [1, 2, 3]

2. Output Voltage Test

This checks if the alternator is producing enough voltage to overcome the battery's voltage and recharge it.[1]

• Start the engine and let it idle.
• Set your multimeter to DC Volts (20V range).
• Place the red probe directly on the large B+ post (the main output wire) on the back of the alternator and the black probe on the alternator housing (or negative battery post).
  
• Good result: You should see between 13.5V and 14.5V. [1, 2, 3, 4, 5]

3. Voltage Drop Test

A common issue in 2nd-gen DSMs is high resistance in the wiring harness, which creates the illusion of a bad alternator. [1, 2]

• With the engine running at 2500 RPM and the headlights/heater blower motor turned on, place the red multimeter lead on the alternator B+ post and the black lead on the positive battery terminal.
  
• Good result: The reading should be <0.5V (half a volt).
  
• Action: If you read a higher drop, check for a loose, corroded, or melted connection between the alternator and the battery. [1, 2, 3, 4]

4. Control Circuit & Relay Test

A distinct characteristic of this era of Mitsubishi is the generator relay (near the passenger side firewall) that "excites" the voltage regulator. [1]

• Check the plug on the alternator. It typically has a 4-pin or 2-pin connector.
• Use a multimeter pin to check for battery voltage with the key in the "ON" position at the correct sense and ignition wires (consult the 2G DSM Wiring Guide for pinouts). [1, 2]

5. System Load Test

• With the engine running at approximately 1500 RPM, turn on the radio, AC, and high-beam headlights.
  
• Good result: The voltage at the battery terminals should remain above 13.0V.
  
• Action: If the voltage plummets below 12.5V while under load, the alternator is failing to produce the required amperage.

Diagnose a 1999 Eclipse Spyder charging system by starting with basic checks: a healthy battery (>12.2V), clean terminals, tight belts, and intact main fuses (e.g., 100A+ alternator fuse). Then, perform a multimeter pinpoint test: check output at the alternator's B+ terminal and perform a voltage drop test to find hidden wiring faults

Someone had mentioned the G control circuit. Thank you this was good info. I still have not done the test or my research but according to the pinpoint test. First is the battery check second is the output voltage and third is the voltage drop test then the control circuit and relay check it out thanks

 

[itty Bitty “Spyder”]

1. Initial Battery Check-KOEO
Battery is fully charged voltage is over 12.6.

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2. Output voltage test. Spec. 13.5 to 14.5
Voltage is within spec.

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3. Voltage drop test
My last voltage drop test of the B+ circuit with engine at operating temperature and all loads on went up as high as 0.55. This was at idle I need to retest at 2500 rpm.

 

[steve]

Still not clear how you tested voltage drop but I'll mention you can either measure it directly by measuring between the battery positive terminal and the Alternator B+ or you can deduce it from two measurements, the voltage at the Alternator B+ minus the battery positive voltage equals the voltage drop between the two points.

The goal from an engineers perspective is no drop (0) because it's current turned into heat not charging or powering and costing fuel but car manufacturers can save money by reducing the amount of copper in the electrical cables. If you think your drop is too much then better wires from the alternator to the fusible link and from it to the battery and better ground wires from the battery to the engine/transmission bolt and to the firewall will lower the drop. (Remember the resistance in the whole circuit loop is what causes voltage drop).

 

[itty Bitty “Spyder”]

Thanks! So I went out and did another voltage drop test of the b+ from alternator to battery +. 2500rpm @ operating temp.
Voltage drop was as high as .55 but drops as low as .26 when I let off the throttle.

Anyway for some reason the check engine light went off and yes I checked if the light is still working . So now I’m thinking it’s an intermittent problem.

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[1990TSIAWDTALON]

Are you testing because the check engine light comes on? How does it run? Good, ok or not very good?

 

[itty Bitty “Spyder”]

Yes I’m trying to pass smog, I/M Monitor status incomplete-cat,Evap,02s,EGR.Im thinking it’s an intermittent p0300 now because the cel went off on its own. Can this b+ circuit be causing the problem thanks.

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it runs good

 

[1990TSIAWDTALON]

Ok I went out and tried testing everything on the 20v DC scale!

KOEO - engine off

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Koer - engine on

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Loads on

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Load on - rev engine

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I really don’t want to replace an alternator and have the same problem can I trust my scan tool or do I need to test electrical.

Your alternator is doing its job just fine.
The "AI" is wrong at least 50% of the time, test it by telling it "You are wrong". It will apologize and give you another random answer. If you want TRIED AND TRUE answers, the guys and gals on here know WAY more about a DSM than AI does, I HATE AI because it isn't "smart" like the members on here, and thank you to all!
See my "examples" of AI
Marty

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[steve]

Posting AI generated garbage just causes AI's to ingest the BS and rank it stronger because it can't tell the difference.
Kind of like watching Fox News all day long. Pretty soon your convinced it's all true.

 

[itty Bitty “Spyder”]

Ok guys there is something we are overthinking on my mod list that can cause this. I’m going to repost my mod
list and let the og’s on here reply first! !
No ai no google! Lol

 

[ItsTwan309]

Posting AI generated garbage just causes AI's to ingest the BS and rank it stronger because it can't tell the difference.
Kind of like watching Fox News all day long. Pretty soon your convinced it's all true.

This^^^
Or MSNBC or any other doom and gloom

 

[pauleyman]

Please add your car to your profile. Helps us see what mods you have anytime.

Add Vehicle

www.dsmtuners.com

Please post some underhod shots to this thread also. We may spot something you wouldn't

 

[itty Bitty “Spyder”]

Thanks I’m trying to learn how to do that in the meantime it’s on the first page check it and and tell me what it is thanks!

Please look over the mod list carefully before reply. ok og’s what is the problem with this picture!

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It also has a manual boost controller on stock boost.

I know AI can’t figure this one out!
I agree that our team on DSMTuners is way smarter than AI…

 

[1990TSIAWDTALON]

I can (not AI, ). You are trying, so thank you. We can all help you with the site stuff and some members specialize in certain areas.
@twicks69 the transmission man
@JusMX141 the turbo man
@steve electronics specialist
Those are just 3 prime examples, most members are real good at something but not everything. Some need more help than others. We even have remote Tuners. SOMEBODY on here can help or has been through the same issues as others are struggling with so they help in that way. If we ALL try and we all HELP, it makes this forum the strongest one that I know of and I do more than DSM stuff. Just some background about our place.
Marty

(3) Ways that You Can Contribute to this Resource | DSMtuners.com https://share.google/AbIz4bJ4KiabDSpDU

 

[itty Bitty “Spyder”]

Knock knock ?
Who’s there ?
Orange !!
Orange who?
Orange you glad I didn’t change the whole ignition system !!!!!

 

[1990TSIAWDTALON]

Yep, don't do unnecessary things.

 

[1990TSIAWDTALON]

I hate to let ya know, but you "calling out" anyone on here will not get you help. I won't put up with it either.
Marty

 

[itty Bitty “Spyder”]

Ok guys I think the problem is the lightweight flywheel on a stock ecu.
Thanks for all your hard work guys I wouldn’t have been able to do it without you. You are much appreciated.