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In Need of Second Opinions on Electrical...

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gunnermaiden

Proven Member
72
1
Jul 27, 2016
Phoenix Area, Arizona
First off, apologies for the LONG read in advance.

Secondly, I'm very sorry if some things have already been mentioned in this post, I could not seem to find the clear details and answers I was looking for.

Thirdly, hello everyone!

I have a 99 GS (auto) 420a non turbo that I picked up as a running-project to have it built the way I want. My main goal right now is to restore it and have the proper work done on it to continue keeping it on the road the way it was meant to be. These cars are more and more difficult to find in good, unmolested condition and I want to save this car. Fortunately for me, money isn't a problem but that does NOT mean I am wasteful with my funds, I am a careful spender and rather particular because I used to be poor as fck and I worked hard and long to be where I am now. Moving forward,

The kid who owned it before me destroyed it. Wires every which way, leaking trans, lots and lots of electrical problems, which seems to be most of my problems. Here's a description of the things going wrong that I believe are all electrical related:

-Rough start. Starts everytime, just roughly
-Will not run cold, must wait for it to warm up
-Rough idle -- sometimes bogs down and almost stalls out at stop signs/lights
-Dash is obliterated. The only thing that functions properly is the speedometer. Won't display anything.
-Interior lighting (when the headlights are on) flashes on and off randomly and can't seem to stay on
-A/C is out. Recharged it, blew cold, but then made my PCM(?) overheat and then A/C lost power (being in Phoenix, it's a big deal to not have an A/C)
-Upon driving, trans is unpredictable. Some days it has zero issues, moving through no problem. Other days it won't move into third. I believe this is electrical considering how the rough the wiring is visibly. However, it leaks and I don't know the status of the leak.
-I guess I might as well mention that the doors only open from the inside, no door panel cover on the driver's side, and no radio in it at all. The previous owner removed it since you have to leave the windows down to get in it and it looks like he messed with the wiring behind the radio compartment as well.

There are a lot more issues, although the electric is my main concern right now since I am mostly concentrated with how healthy it runs and not how it looks/how comfortable it is at the moment. The body is straight with no rust (AZ car). It might be at 177xxx original miles, but I don't know how accurate that reading is on the dash considering nothing else on it works properly.

I did drop it off at a garage that specializes in restorations last week. This week I received an email from the owner that said this:

Ac system low on freon, serviced system & ac does blow cold at this time but shuts off do to computer temperature going high. The Gauge on the dash shows normal but when you hook up the computer scanner it show high above 230 but then loses temp & drops below normal and back up. Lights on your dash like the check engine light not coming on, there are several codes that come up on scanner. The starting issue has always started but sometimes not so easy. With all the wires just routed places, I think that the best place to start on this car would be a new wire harness & PCM

So here's what I need a second opinion on. My quote is roughly 10 hours worth of labor to replace and rewire the harness and PCM. Which is going to end up to be around $1k or so (it's stated that is could end up being a bit less in the end). Is there ANYTHING else I need to have replaced for this particular part of the project? Any related related relays /computers other than the PCM? Any fuses? Suggestions to look for to advice the shop on? Owner of the shop has not yet responded to what the codes are saying exactly. I know that 2 off hand already are going to be for the exhaust and the airbag (aftermarket parts installed by previous owner), but I have no clue what the rest could be. Note: I am going out and buying the replacement parts and dropping them off at the garage since I wanted to be the one to pick the parts, which is why I am asking these questions
 
try changing your coolant temp sensor. its reading too high and its shutting off the a/c compressor.
 
I've never heard of anyone removing the CTS. What's in the hole where the CTS is supposed to be? Take a pic if you can.

Also, when I recommended changing the tps I didn't realize you were actually throwing trans codes. You can change it if you want, but I doubt it will help.
 
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try changing your coolant temp sensor. its reading too high and its shutting off the a/c compressor.
Will do, I drove it for an hour this morning and had zero issues with the A/C, but we'll see if that changes on the way home tonight.

@PlanZero , yeah me either, I'll try to get a pic soon. Question for you, I read on a different DSM forum site that if you clear the codes using the reader, unplug/or completely change the TPS you can start from a clean slate to help decipher the problem. I've never heard of doing this, what do you think? Also I checked the HOT zone levels today, still good.
 
That is untrue. Clearing codes with a reader won't do anything. Technically when replacing the IAC with a new one you're supposed to disconnect the battery to allow the ecu to reset, but I've replaced several tps and IAC without disconnecting power.
 
That is untrue. Clearing codes with a reader won't do anything. Technically when replacing the IAC with a new one you're supposed to disconnect the battery to allow the ecu to reset, but I've replaced several tps and IAC without disconnecting power.
Glad you cleared that up for me, also I just crawled underneath it in the parking lot, the pan on the transmission is scraped up pretty bad along with some dents (previous owner did mention to me he had the car lowered at one point, probably ran something over). Hopefully that's my only reason for a leak on the trans...

*Edit, typed the same sentence twice.
 
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@gunnermaiden If you ever need help with your DSM look up AZ Speed Center. They focus on DSMs and have done a lot of work to my 4g63 but they do it all. Tunes, rebuilds, whatever LOL. Shop owner is very knowledgeable about DSMs and is always willing to help. A plus is that they're in Phoenix!:hellyeah:

Also, if you haven't already, join DSM Arizona and AZ-DSM Force on facebook :thumb:
 
@gunnermaiden If you ever need help with your DSM look up AZ Speed Center. They focus on DSMs and have done a lot of work to my 4g63 but they do it all. Tunes, rebuilds, whatever LOL. Shop owner is very knowledgeable about DSMs and is always willing to help. A plus is that they're in Phoenix!:hellyeah:

Also, if you haven't already, join DSM Arizona and AZ-DSM Force on facebook :thumb:

Awesome, thank you so much!! I've been looking for a place that knows a load about DSM's in town! Don't know why I couldn't find it, but definitely thanks so much for letting me know! I don't have Facebook though, I'm one of those weirdos hah.
 
@gunnermaiden no problem man! I made a fb just to join the car groups haha. But i highly recommend AZ Speed Center, if you had a fb you would see how much the community loves them. They really go out of their way to help get everyones DSMs running ROFL
 
Question: How can I tell if a solenoid/relay is fried? I'm starting to suspect some of my idling/hard start problems are the ASD, I'd like to check it before buying the part and not sure how to go about this. What should I look for when I unplug them to check if they're good? If my PCM is bad, could it be destroying other relays/solenoids? Also, what's a good test to check if my PCM is actually dying? Couldn't really find anything clear on that one.
 
Question: How can I tell if a solenoid/relay is fried? I'm starting to suspect some of my idling/hard start problems are the ASD, I'd like to check it before buying the part and not sure how to go about this. What should I look for when I unplug them to check if they're good? If my PCM is bad, could it be destroying other relays/solenoids? Also, what's a good test to check if my PCM is actually dying? Couldn't really find anything clear on that one.

I'm sorry, what's an ASD? Relays can cause problems; the easiest way to check is to swap it with a known working one (like for the headlights, or something that won't interfere with operations); solenoids are usually just voltage based; the ecu just fires off a signal to see if they're working. You can test them with a basic multimeter.
 
ASD = automatic shut down
ASD relay = MFI relay

if your ASD relay was bad, your injectors wont work, neither will the coil.

I just noticed the picture of your engine bay. It looks like you may not have a good ground. where do you have the (-) cable (off the battery) attached to the chassis?

here is the part out of the manual on checking relays:
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here are the diagnostic flow sheets for hard starting and unstable idle.
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if you haven't already, you can go HERE to download the service manual and find other useful sh1t
 
Last edited:
First off, apologies for the LONG read in advance.

Secondly, I'm very sorry if some things have already been mentioned in this post, I could not seem to find the clear details and answers I was looking for.

Thirdly, hello everyone!

I have a 99 GS (auto) 420a non turbo that I picked up as a running-project to have it built the way I want. My main goal right now is to restore it and have the proper work done on it to continue keeping it on the road the way it was meant to be. These cars are more and more difficult to find in good, unmolested condition and I want to save this car. Fortunately for me, money isn't a problem but that does NOT mean I am wasteful with my funds, I am a careful spender and rather particular because I used to be poor as fck and I worked hard and long to be where I am now. Moving forward,

The kid who owned it before me destroyed it. Wires every which way, leaking trans, lots and lots of electrical problems, which seems to be most of my problems. Here's a description of the things going wrong that I believe are all electrical related:

-Rough start. Starts everytime, just roughly
-Will not run cold, must wait for it to warm up
-Rough idle -- sometimes bogs down and almost stalls out at stop signs/lights
-Dash is obliterated. The only thing that functions properly is the speedometer. Won't display anything.
-Interior lighting (when the headlights are on) flashes on and off randomly and can't seem to stay on
-A/C is out. Recharged it, blew cold, but then made my PCM(?) overheat and then A/C lost power (being in Phoenix, it's a big deal to not have an A/C)
-Upon driving, trans is unpredictable. Some days it has zero issues, moving through no problem. Other days it won't move into third. I believe this is electrical considering how the rough the wiring is visibly. However, it leaks and I don't know the status of the leak.
-I guess I might as well mention that the doors only open from the inside, no door panel cover on the driver's side, and no radio in it at all. The previous owner removed it since you have to leave the windows down to get in it and it looks like he messed with the wiring behind the radio compartment as well.

There are a lot more issues, although the electric is my main concern right now since I am mostly concentrated with how healthy it runs and not how it looks/how comfortable it is at the moment. The body is straight with no rust (AZ car). It might be at 177xxx original miles, but I don't know how accurate that reading is on the dash considering nothing else on it works properly.

I did drop it off at a garage that specializes in restorations last week. This week I received an email from the owner that said this:

Ac system low on freon, serviced system & ac does blow cold at this time but shuts off do to computer temperature going high. The Gauge on the dash shows normal but when you hook up the computer scanner it show high above 230 but then loses temp & drops below normal and back up. Lights on your dash like the check engine light not coming on, there are several codes that come up on scanner. The starting issue has always started but sometimes not so easy. With all the wires just routed places, I think that the best place to start on this car would be a new wire harness & PCM

So here's what I need a second opinion on. My quote is roughly 10 hours worth of labor to replace and rewire the harness and PCM. Which is going to end up to be around $1k or so (it's stated that is could end up being a bit less in the end). Is there ANYTHING else I need to have replaced for this particular part of the project? Any related related relays /computers other than the PCM? Any fuses? Suggestions to look for to advice the shop on? Owner of the shop has not yet responded to what the codes are saying exactly. I know that 2 off hand already are going to be for the exhaust and the airbag (aftermarket parts installed by previous owner), but I have no clue what the rest could be. Note: I am going out and buying the replacement parts and dropping them off at the garage since I wanted to be the one to pick the parts, which is why I am asking these questions
Wow! Where to start....Any of those one or two things themsleves in my opinion aren't a big deal and probably an easy fix but the list goes on and on which is never a good sign. Sounds like a lot of things and not necessarily cheap fixes are in play especially regarding the wiring and ecu and transmission let alone the entire AC system in question. I'm not trying to sound like a negative Nelly but if you decide to fix that car I guarantee you won't get half the money back that you put into it. I wish you luck as I owned a 420a and I'm aware of the headache.
 
@PlanZero , I'll try the test you mentioned and put the multimeter in my shopping list for the parts store.

@dustyboner , so glad you posted those, I couldn't get the manual that was provided on this site to fully download. I saved them! Definitely useful! Also, I feel dumb as sht now that you pointed out the negative battery cable... how did I miss that :ohdamn:. Definitely going to check that out tomorrow after I close up my shop.

@DavidJamesDSM , the more research I do and the more this thread develops I'm starting to pinpoint more things and it sounds like it's getting simpler each time I discover something. I have high hopes! The A/C is actually running great now. I've been "testing" out the car and dailying it this week (mainly because my actual daily ate a Prius on the freeway and is in the bodyshop) and it seems the more I drive it, the harder I drive it, the more it works it's problems out. Hasn't had the third gear issue since last week and my A/C is ice cold with no over heating or dying out. And I've hardly done anything other than eyeballing, tightening things that were loose here and there, and checking fluids everyday. Next week I'm actually going to go into action now that I'm armed with adequate knowledge on where to start, because I know nothing goes away on it's own. Gotta love these 90's cars and their big personalities :p.
 
@PlanZero , I'll try the test you mentioned and put the multimeter in my shopping list for the parts store.

@dustyboner , so glad you posted those, I couldn't get the manual that was provided on this site to fully download. I saved them! Definitely useful! Also, I feel dumb as sht now that you pointed out the negative battery cable... how did I miss that :ohdamn:. Definitely going to check that out tomorrow after I close up my shop.

@DavidJamesDSM , the more research I do and the more this thread develops I'm starting to pinpoint more things and it sounds like it's getting simpler each time I discover something. I have high hopes! The A/C is actually running great now. I've been "testing" out the car and dailying it this week (mainly because my actual daily ate a Prius on the freeway and is in the bodyshop) and it seems the more I drive it, the harder I drive it, the more it works it's problems out. Hasn't had the third gear issue since last week and my A/C is ice cold with no over heating or dying out. And I've hardly done anything other than eyeballing, tightening things that were loose here and there, and checking fluids everyday. Next week I'm actually going to go into action now that I'm armed with adequate knowledge on where to start, because I know nothing goes away on it's own. Gotta love these 90's cars and their big personalities :p.
Well I'll admit I'm proud of you for biting the bullet and jumping head first into this car. I know speak for a lot of people on this website, yourself and I included, that the Mitsubishi community is very forgiving and always welcome to lend a hand. Keep it up fam :) glad to hear your eclipse is working out
 
Okay, more pictures upon request:

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This was how I found it the day I bought it, pulling it out again for photo purposes. I tried to follow the wire but the property manager was out patrolling and I couldn't risk getting caught doing something I'm not supposed to >.> (maybe I'll start planning a schedule to go to the AutoZone parking lot to do this..)

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How the previous owner wired up the aftermarket HID's (red wire with pathetic electrical tape). Hasn't been causing problems so far but I thought it was funny LOL

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Where my ground is going. This is directly behind the radiator on the driver's side, looks like it's attaching to the frame. It continues to move downwards and underneath the engine (obviously) but it was a weird angle and my hand doesn't move like that hah.

Haven't drove or started it for 2 days now (got the daily back), dollar-coin sized puddle where the trans is leaking, levels still looking the same... while I was out there I confirmed that there is NO engine oil leaks, power steering leaks, etc etc. Just the trans leak.

I wanted to check the relays more and run the multimeter but I surely would've been caught, definitely need to plan a day at the AutoZone parking lot soon. My only fear with that is that I'll mess it up more and not be able to get home L O L
 
the first picture looks like the plug for a HID ballast.

as far as the ground it should ground to the body like in the picture and then it goes down and bolts to the transmission to give the starter a good ground. if it only attatches to the transmission and not the body, it could cause alot of electrical problems.
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the first picture looks like the plug for a HID ballast.

as far as the ground it should ground to the body like in the picture and then it goes down and bolts to the transmission to give the starter a good ground. if it only attatches to the transmission and not the body, it could cause alot of electrical problems.
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Yikes, my ground doesn't match the picture or description at all... Just bumped that up the priority list.

And the first picture, why tf wouldn't the previous guy who owned it just not work with that harness instead of the red wire in the 2nd picture? Is that common to find on these cars?
 
Are you sure that wire is for the HIDs and not a fuse for an aftermarket stereo? Where does it go? Most slim HID kits are plug and play with the factory headlight harness. No idea why the PO would make it more complicated.

I'm not entirely sure where it goes. Sorry I'm such a n00b :(. I do know the stereo harness is not hooked up at all, the wires and harness were left bunched in a rat's nest inside the stereo compartment not attached to anything. PO ripped the stereo out after he broke the door handles off and busted a door handle rod inside the door and apparently decided to take the whole wiring for the stereo with the stereo as well. There's not even any wires for the speakers :toobad:. This is why we can't have nice things, hah.

When I get it to location where I won't get fined for looking at it, I'll take better, more detailed pictures of all the other shenanigans I find. Didn't really find what I was looking for the other day unfortunately
 
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