97 Intrepid keeps blowing Engine Control fuse under the hood when i try to start it
24 Answers
OrLackThereof answered 13 years ago
The fuse you describe....where is it? In the fuse block, or are you talking about a large, primary fuse right off of the positive battery lead? If it's in the fuse block....disconnect your battery then remove the fuse block, flip it over and inspect it with a light and look for damage i.e. melted portions of plastic, corroded or melted connections, etc. I'm thinking if we're talking the fuse block here, and the starter and ECM fuses are next to eachother in the block, that they're shorting to eachother. Make sure you've got the proper amperage fuse for both the starter and ECM.
yes its in the fuse block its a 20A fuse next to the starter fuse. I took the fuse block off and checked it nothing looks damaged at all.
OrLackThereof answered 13 years ago
It's right next to the starter fuse? Count on the block being bad for sure then...when you energize the starter circuit, it's jumping to the ECM circuit and blowing the fuse. The damage may not always be obvious. If you're feeling froggy, pull the ECM and starter circuit wires OUT of the fuse block carefully, then crimp-spade them, plug their fuses in, and try it. That will take the fuse block out of the picture and isolate the two circuits.
OrLackThereof answered 13 years ago
Or pull the ECM fuse and put a voltmeter on both sides of the female spades in the block while someone cranks the car. If you see a voltage spike on the ECM side, there you go, shorted block.
ok thanks im going to go try that real quick and see what happens ill be back in a few i hope this works im trying to get this car running so i can make it home for thanksgiving.
OrLackThereof answered 13 years ago
Keep me updated. By the way if this is helpful, I could use the rep points.... :)
Ok so i took the engine control fuse out and used a mult-meter on both the prongs where the fuse waswhen i tried to turn the car over the voltage reading cut in half
OrLackThereof answered 13 years ago
Remember you're wanting to check amperage as well....I may have mistakenly said voltage above, my mistake.
Same thing when i try start car the amp reading drops
OrLackThereof answered 13 years ago
Okay, that's normal. Does it pop the fuse while cranking or right at start? There may be a short going into the ECU then instead. When did this all start...did it do anything strange when it was running last?
It does it when its cranking. i was driving it and everything was fine then i pulled into a driveway to turn around and i backed up put the shifter down into the slap shift position (which i had never used before) and when i went to pull forward the car just died and wouldnt start after that it just keeps blowing that fuse
ok i take that back ive used the slap shift before but never starting off so ive never had the slap shift in first gear before this
OrLackThereof answered 13 years ago
Here's what I'm not getting. If you're not getting a spike at the fuse, then you can't be blowing that fuse. But you ARE. Which tells me that your digital meter, being digital and with no graphing function, is not sampling fast enough and is missing the spike that's popping your fuse. If you can get your hands on an old-school analog meter (needle), it *might* be able to capture it...but otherwise, I'm thinking you're gonna need a graphing meter. And you said you're sure the correct amperage fuse is installed, correct? I would suggest going up 5amps on the fuse, or mayyyybe even 10, to see if it still pops, but I'm really afraid of the possibility of frying your ECU so I wouldn't do that.
speaking of that how can you tell if the ecm is fried. The fuse block calls for a 20A fuse thats what was in it and i tried a 30A it blew it to
OrLackThereof answered 13 years ago
I don't know if there is a way to test it to be honest with you, seeing as how complex it actually is. Most of the time the solution here is to swap it with a known-good one and see if it runs. However, with your particular problem, it's a toss-up as to whether you might fry a new one....because I've never heard of an ECU failing and popping the fuse, they usually just quit running or throw multiple codes that are more or less random jibberish. You can *try* swapping it if you want man but it won't be cheap....your best bet for that is going to be a scrap yard.
If i try a diff ECU does the intrepid it comes off of need to be a slap shift to.
OrLackThereof answered 13 years ago
Try to match the part numbers....it needs to be the same year or within the bracket where everything was carry-over and nothing was changed between years.....needs to have the same engine.... If the transmission is different, it will start and run but it won't be driveable. But if you're ONLY looking to test it and not keep it, just make sure the engine, connections, and years match up.
OrLackThereof answered 13 years ago
That isn't the route I would necessarily go, but give it a shot if that's what you want to do, just do your best to make sure it's returnable if it doesn't work... Just don't up the amperage on that fuse, keep it stock.
THANKS ALOT DUDE!!!! I bypassed the fuse box like u said and separated the circuit with fuse and all and IT RUNS!!!
OrLackThereof answered 13 years ago
Glad to hear it....I had a feeling, but I hate to start bypassing things without a confirmation!
Ya i thought about trying to do that to start with but wanted to wait and see if somebody with a little more knowledge than me on the subject would suggest it you know what i mean. I was bout to give up on being able to get it fixed and be able to make it home for thanksgiving im in cleveland going to a school for power sports tech. THANKS AGAIN MAN!!!
I had the 20amp engine control fuse keep blowing in my 97 Intrepid while driving. I researched numerous forums and one thing was consistent. Most posts stated that this is due to an electrical short. After investigating my wiring, I proceeded to remove part of my car's computer. I found condensation in the computer. I dried it out with a hair dryer (on warm, not hot) and the car has been fine since. I should add that my car had been sitting in rainy conditions for a week while I was on vacation. I hope this helps guide anyone else who may have this issue.
I’m having this same issue. However when we bypassed it, with the fuse, it continued to blow. If we bypass the fuse altogether, it runs. Any suggestions??