Pennock's Fiero Forum
  Technical Discussion & Questions
  Fusible links keeps blowing after new battery, Help!

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version


next newest topic | next oldest topic
Fusible links keeps blowing after new battery, Help! by Bridgetown
Started on: 07-06-2014 02:45 PM
Replies: 20 (744 views)
Last post by: Bridgetown on 07-13-2014 06:14 PM
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-06-2014 02:45 PM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
I installed my LED marker lights and took my car for a drive yesterday. I was driving with the park lights on to make sure everything was working good. Parked the car, and like a dough head, I left the park lights on. Car was dead of course. Tried to put my trickle charger on it, but it was too far from a plug so there was too much resistance from the extension cord. Then i got the bright idea to jump it with my truck. Snap,crackle, pop my fusible link "E" to the alternator vaporized itself.
Pulled my battery, put it on the charger, it wouldn't take a charge. Figured the battery is done(its about 6 years old now), bought a new battery, replaced the fusible link, exactly like the old one. Fried the same link again.
Checked all the links and wires coming off the c500, alternator, and starter wiring. All the wiring looks good, replaced the link again, hooked up the battery, bam! Fried it again.
Now I have no idea what to check. Almost all my power wiring is in newer condition. Anyone have any ideas what I should check?
IP: Logged
PFF
System Bot
rogergarrison
Member
Posts: 49583
From: A Western Caribbean Island/ Columbus, Ohio
Registered: Apr 99


Feedback score: N/A
Leave feedback





Total ratings: 552
Rate this member

Report this Post07-06-2014 03:43 PM Click Here to See the Profile for rogergarrisonClick Here to Email rogergarrisonSend a Private Message to rogergarrisonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Did you use a meter, test light or continuity tester to verify all the other wires and links are good too ? Did you replace the fusible link with one rated the same ? Have you tested the alternator at any point. You were probably right the battery was junk. 4 years is about the life expectantcy of a battery, and when they are that old and you run them dead...it usually will not recharge. Are you turning everything off when you try to charge it. Check the wires going to the alt and starter for tightness too.
IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-06-2014 03:55 PM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
The link(s) I made was exactly the same as the one that was in there working fine for a few years 12awg with crimp connectors approx. 6" long. I didn't have access to a multi meter at the time.
I would be surprised if it was a bad alternator, it's never given me any trouble at all. I will check the connections to see if any are loose. Seems weird that I have had a flawless working system, and one dead battery causes all this. I really hate electrical issues!
IP: Logged
tebailey
Member
Posts: 2597
From: Bay City MI
Registered: Jan 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post07-06-2014 04:14 PM Click Here to See the Profile for tebaileyClick Here to Email tebaileySend a Private Message to tebaileyEdit/Delete MessageReply w/QuoteDirect Link to This Post
Sounds like you may have fried your alt.
IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-06-2014 05:11 PM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
Hmmm, can I test it in the car to see if that's it?
IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-06-2014 06:43 PM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
Well, I don't think it's the alternator. While I was working on the car, I put the old battery on the charger on the 2 amp setting. I was able to get it charged up to 80%. Wouldn't go any higher. So just for giggles, I swapped the new battery for the old one (now at 80% charged). With a new fusible link, it didn't blow. With the key on, everything works. But the car won't start now, turns over plenty fast, so I don't think it's for lack of power. Just wont fire up. Checked all the fuses, all good. What do you think? Fried my ECU perhaps?

[This message has been edited by Bridgetown (edited 07-06-2014).]

IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-06-2014 10:13 PM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
Ran out of time today, I'll have to go back tomorrow to check for fuel and spark, and hook my scanner up to the ecu. What else should I check?
IP: Logged
phonedawgz
Member
Posts: 17009
From: Green Bay, WI USA
Registered: Dec 2009


Feedback score:    (23)
Leave feedback





Total ratings: 290
Rate this member

Report this Post07-06-2014 10:41 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
Putting the charger on backwards could kill the Alt, could kill the ECM and could burn up the fusible links.

Usually when an ECM isn't working it is because the ECM isn't receiving power.

Does the check engine light come on key on engine off? It should. If it doesn't that points to a non-functioning ECM

Does the fuel pump run for two seconds when you turn the key to on (but do not crank it at all). If it doesn't that points to a non-functioning ECM.

If the ECM isn't functioning (fails BOTH above tests) take off the console remove the ECM plugs, unscrew the 4 bolts that hold the ECM to the plastic bracket (10mm). Remove the two plugs from the ECM. If your harness has ECM plugs with metal clips you WILL need a small screwdriver to pull them up to release them. Once you have the ECM plugs off of the ECM then take off the 4 blue or gray secondary terminal retention clips. Then look closely at the connectors and locate sides A&B (the small connector) and sides C & D) the big one. Note where pin 1 and pin 12 or 16 is for each.



Then plug the connectors back into the ECM. Be careful to not short anything out or probe pins other then the ones listed. These tests don't mean much without the ECM plugged in place. Using either a 12v test light connected to ground, or a volt meter with the negative lead connected to ground test the following leads.



Check for +12 on the TWO unswitched power leads B1 & C16 (both wires Orange)
Check for +12 on switched power wire (Key On) A6 (Pink or Pink/Black)

---------------------------------

2.5 alternate instructions

You will have to pull off the red and blue secondary pin retention devices.

Here is the wiring diagram of the 85 - 88 2.5 ECM. Again check for power on the Orange wires on Pin 15 (White Connector) ajd switched power on the Pink or Pink/Black on Pin 16 White.



84 - 2.5 - Hit me up if you have an 84 2.5 since neither of these match that ECM.

----------------------
Power to all the leads of the ECM but no function? Bad ECM

No power to the unswitched pins of the ECM? Check the ECM reset connector. If you don't have power there either then check the fusible link for the ECM.

[This message has been edited by phonedawgz (edited 07-06-2014).]

IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-06-2014 11:00 PM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
Check light comes on and pump runs, with key forward.
Also my innovate wideband connected to the ecu fine, and there were no trouble codes. I have another scanner that is a proper diagnostic type, I was going to hook that p tomorrow. Would there be a code if the ecu got cooked

[This message has been edited by Bridgetown (edited 07-06-2014).]

IP: Logged
phonedawgz
Member
Posts: 17009
From: Green Bay, WI USA
Registered: Dec 2009


Feedback score:    (23)
Leave feedback





Total ratings: 290
Rate this member

Report this Post07-06-2014 11:03 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Bridgetown:

Check light comes on and pump runs, with key forward.


Ok well then the ECM is at least somewhat functional. Time to look elsewhere however that doesn't mean the ECM is 100% ok.

Next check - While cranking does the tach rise to 200 rpm and then fall back to zero when you are done cranking? - Note what the tach says with the key OFF means nothing.

Which engine?

Have you checked for spark?

No response from the ECM is about the only code you will get to know that it is dead. Since it is communicating and the fuel pump relay and check engine light output are working I'd assume for now that it is working. You COULD have bad injector drivers however not real likely.

One more check for the ICM (Ignition Control Module) is to just bump the starter. Doing so should send an ignition pulse to the ECM. The ECM will then turn on the fuel pump again and shut it off two seconds later. If you are getting both the tach rising and fuel pump coming on then it looks like the ICM is working. If you lack both then it's time to look at the primary ignition system.

Don't actually crank the engine for the test. If you crank the engine you will build up oil pressure and the oil pressure switch will turn on the fuel pump. You will know it's the oil pressure switch turning it on if the fuel pump stays on for a long time and you don't hear the relay drop two seconds after you bump the starter.

[This message has been edited by phonedawgz (edited 07-06-2014).]

IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-06-2014 11:07 PM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
Tach did read rpm while cranking, didn't check what value though.
Engine is 3400 running OBD2 (your harness actually)
I will confirm fuel and spark tomorrow. Best technique for that?

My car is in storage so I can't work on it unless I drive to it. Sucks. Have to check more stuff tomorrow after work.
Thanks a lot for your help so far.

[This message has been edited by Bridgetown (edited 07-06-2014).]

IP: Logged
PFF
System Bot
phonedawgz
Member
Posts: 17009
From: Green Bay, WI USA
Registered: Dec 2009


Feedback score:    (23)
Leave feedback





Total ratings: 290
Rate this member

Report this Post07-06-2014 11:14 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
Well now you are making it hard.

You need to do the two following tests with the injector plug still on the injector. Slide a pin down past the seal till you can read voltage on the pin. First check the pink wire. Check to see what voltage you have during cranking. Then check the other pin while cranking. If the voltage on the non-pink pin is about 4V below the pink during cranking the ECM is firing the injectors.

IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-07-2014 11:29 AM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
Correction, my tach is not moving during cranking. The fuel pump doesn't come on again when I bump the starter. It does come on after it cranks over for a bit though.
IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-07-2014 11:51 AM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
Further testing for spark shows no spark during cranking on cyl 1 & 5. Didn't check them all but I think it's safe to say the issue is spark.
I checked power at the ICM. I have 12v to the ICM and the ground checked out good too.
Didn't have time to check for CKP signal. What should that be putting out to the ICM?
IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-07-2014 11:49 PM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
Had a bit of time to look at the car. Checked the CKP signal during cranking, it's putting out .06 vac during cranking, which I believe is within spec. I will check its resistance tomorrow, but I suspect it's not the crank sensor. Looking like most likely the ICM.
IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-08-2014 02:19 PM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
Checked some more stuff today. CKP sensor is holding a steady amperage during cranking, that shouldn't be should it? Isn't it supposed to occilate up and down during cranking?
Also resistance across the sender is 950 ohms, it is supposed to be between 300-900, right?
IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-09-2014 10:42 PM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
Bump!
IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-10-2014 09:59 PM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
Did some more research, and checking.
My CKP sensor is holding a resistance if .6 , which is within spec, as is my AC volts.
All signs are pointing to a faulty ICM. I picked up a new one, and I'll install it tomorrow. We will see what happens.
IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-12-2014 10:39 AM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
Installed them new ICM. Car ran ok by had a misfire over 2.5k rpm. I didn't have much time, so rather then test for bad coils, I replaced them. The car smoothed out a lot. But there is still a miss at full throttle. Otherwise the car runs perfect. Any ideas what I should check?
IP: Logged
phonedawgz
Member
Posts: 17009
From: Green Bay, WI USA
Registered: Dec 2009


Feedback score:    (23)
Leave feedback





Total ratings: 290
Rate this member

Report this Post07-13-2014 11:09 AM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
Old plug wires with too high of resistance can cause coil packs to fail when then can cause the ICM to fail.

They should be less than 10K ohms per foot.
IP: Logged
Bridgetown
Member
Posts: 1210
From: Alberta
Registered: Feb 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post07-13-2014 06:14 PM Click Here to See the Profile for BridgetownSend a Private Message to BridgetownEdit/Delete MessageReply w/QuoteDirect Link to This Post
I inspected the wiring in the ignition system more closely, and found a break in the wire caseing at the crank sensor plug. I swapped the wiring for a good one. The car has no missfire now under full throttle. Thanks for everyone who helped me figure this all out.
IP: Logged
PFF
System Bot

next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock