IHADAV8.com - Turbo Buick Tech, and Nonsense
Tech Area => General Buick Tech => Topic started by: phil_long on September 26 2015, 09:16:43 PM
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Ok, so I got the new water pump on today. Went pretty smooth. Got everything back together, and went to start the car. Well, the car turned over but it wouldn't start(I did have to give it a jump). I figured to check the fuses, and I noticed that the ECM/IGN fuse was blown. Ok, I have a spare 10 amp fuse, so I replaced it. I tried starting the car up again and it didn't start. :013: I go to check the fuse again, and I noticed that it was blown. Really? So I replaced the fuse again after triple checking everything I could in engine bay wondering what was shorting, if anything. Key on, engine off, the fuse blew again. So now I'm really pissed. I decided to change out the control module with a known working one I have here. After doing that, I replaced the fuse again, and Key on Engine off, I noticed my scan master stayed on. I say great, it should start now. I go to turn over, didn't start, check fuse, and its blown. I plan to do the No Start Tree tomorrow, but I don't what could keep blowing this damn fuse. :hmm
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Subscribed. :)
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This is nuts because the car started perfectly fine a week and a half ago. I haven't done anythings except for swap out the water pump. Now, I do have the K&N air filter drying right now so I didn't have that installed. That shouldn't be relevant to the issue, but just thought I'd share.
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Does it blow if you disconnect the ecm connectors?
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Havent tried that. So unplug the ecm and attempt to start. Got it. Keep you all posted
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ecm, maf, module, and esc module are the main things connected to that fuse so I would guess it is either one of those things, or, the wiring going to them.
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Hmmmm, I'll double check the MAF. I did unplug that to remove the intake to clean the air filter. I havent put the air filter back in yet. It was still drying at the time. Thanks Steve. My goal is to get the Buick Highway ready so i can drive around the world in it and meet you guys. :rock:
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Hmmmm, I'll double check the MAF. I did unplug that to remove the intake to clean the air filter. I havent put the air filter back in yet. It was still drying at the time. Thanks Steve. My goal is to get the Buick Highway ready so i can drive around the world in it and meet you guys. :rock:
Got snow tires on it? We live in igloos up here ya' know. :)
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And good rain tires for the wet coast!
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Well come on down. You know, once you get it running.
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Is this the car that had the ECM connectors replaced?
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Yes this is the car that I replaced the connectors on!! Great memory! Snow tires, and tires for the rain. Got it covered. :atbeer:
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Heat shrink /tape looks good on all those joints?
When one of us suffers we a suffer /remember....
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those connectors are solid!! I tripled checked them. Thanks daveismissing.
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Ok, so I had a few minutes yesterday to check some things out. I unplugged the ECM, and the MAF sensor, and Key on Engine off, no problem. The fuse only blows when the start is engaged. The battery is dead so I need to jump it again. Car's been sitting.
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anything around the water pump that could've gotten bumped or pinched that I'm overlooking? So far we know that the issue is during cranking and the ECM and MAF sensor itself can be eliminated...
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I've read a few posts over on the other board because I did a search. One guy found his TCC wire had shorted. I'm gonna get to unplugging some shit. Lol
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After looking at the diagrams, in theory, at least, this cannot be happening :D
Power goes into the ignition switch from a fusible link. When the key is in Run, it goes to the ecm-ign fuse. When it is in Start, it goes to the starter solenoid and the ecm-ign fuse at the same time.
the solenoid is not pulling any power thru the ecm -fuse because it is on the front side of the fuse.
So much for theory, I guess.
The solenoid is the purple wire coming out of the ignition switch, goes thru the bulkhead connector, and goes to the solenoid. If the purple wire, under the dash, has a bare spot in it and the wire going to the ecm from the fuse had a bare spot in it...then the current draw from the solenoid would pull some from the fuse and probably pop it. I would think this is highly unlikely.
More likely, would be under the hood where the purple wire comes out of the firewall and runs across to the starter. I have seen cases where the wiring bundle comes out of the firewall bulkhead and it forks-----this bundle is held up in the air by a stand off that goes over the valve cover stud. When this plastic stand off breaks the wiring bundle drops down until is laying on the valve cover...and that allows it to lay on top of the end of a long screw that comes thru the firewall...I think this screw is one of the accelerator pedal bracket screws.
The harness rubs on the threads of the screw and saws thru the insulation. This can cause some really strange things like blown fuses, blown fusible links and cross circuited connections etc. It is hard to see this screw but you can put your fingers behind the wiring harness and feel it..or pull the harness forward and see it. Sticks out a fair distance.
At that point, you have wires from the maf, esc module, ignition module and a couple of jillion more.
I think I would look at that point and make sure the wiring bundle is not laying on that screw.
I would also be sure the battery had a full charge on it so it does not force things to pull more current than normal
If you don't find a problem with the wiring and the effing screw...discon nect the purple wire from the starter solenoid and see if it still pops the fuse when you hit start.
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Thanks for the response. I'm going to unplug the control module as well to eliminate that as a whole. No way a bad coil pack could cause this? Anything else to unplug and try before fishing through the sea of wires?
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Hmmm....I don't recall telling you to fish around thru a sea of wires...
Let me try again.
1. Make sure the battery is fully charged
2. Make sure the wiring harness is not laying on that screw where the harness comes thru the fire wall under the hood.
3. Disconnect the purple wire from the starter solenoid if the fuse still blows after doing 1 and 2.
Because the fuse only blows in start, I am thinking its not a problem with the ignition module, maf, ecm, and probably the esc module but I do note that you did not mention disconnecting the esc module in the first go round.
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I was joking Steve!!!!
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So I unplugged the control module, ecm, scanmaster, and the MAF. Key on, engine off, fuse was ok. Plugged the Control module back up, key on, engine off, fuse ok. Plugged the ECM back up, the damn car started. :013: So i plug everything else up, and the car is running just fine. Im so pissed because I don't know what the hell happened or what I did. This car has never ran so quiet!! No more leaks from the coolant, and I'm ordering a new serpentine belt to the right sized one. I did check around where you told me to check Steve, and that wiring harness appeared to be fine. I'm losing my mind here. I do think I might invest in some new fans though, because the car runs a little too warm for the thermostat that I'm running. After driving around and giving some throttle, the temps got up to about 183. Seeing that the temp outside is only 62* and my thermostat is a 160, that's a problem. The fans dont sound like they're running as hard as when I first purchased them.
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So either charging the battery fixed the problem (first thing I always check is the battery charge level)
Or moving the wiring bundle when you checked it...
looks like one of the two "fixed" the problem...
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Yup! I want to look into it further I think. You'd be proud! My lazy behind finally cleaned my air filter. Now back to chasing down routine issues. Lol. Thanks a lot for the help Steve.
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I'm convinced that the low voltage is what is blowing the fuse. Not sure how or why, but I allowed the car to sit after driving for a week and half everyday straight, and I go to turn it over and low and behold the fuse pops again(battery died). I'm sure its time for a new battery as I've had this one for many many many years, but I just thought it was odd that a drained battery would cause the fuse to pop.
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In theory, low volts will require more amperes to do the same job. More amperes than the fuse wanted to pass apparently. At least that's my theory.
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And that's exactly what the problem was. The battery has a bad cell. Car is up and running perfectly fine now. :atbeer:
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in the old days, we just rolled it off and popped the clutch...moder n cars have to have a good battery
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gotta love the good old days
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Life was so simple and it looks really good to me now! :)
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Ok Steve, your theory is more than likely correct. Lol. I've replaced the battery in the car because the old one was done anyway. Had been in the car for 9 years. Lol. But, the fuse is still blowing. And, it's NOT during cranking, its just turning the key to on. This makes more sense than the scenario I provided the first time. I'll start back over from the beginning so I can find the culprit. I unplugged the ECM, and the fuse still blew. I'll keep you guys posted.
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Mine had a problem where the injector harness was shorting near the egr valve. Im not sure yours is similar but you could look on the manifold there and see if the harness is on the egr valve.
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Thanks Rich, I'll check that out as well!
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delete
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delete
ignore the diagram...wron g fuse
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so the diagram showing now I should ignore?
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yep, I thought I looked back and you said the ecm-sol fuse was popping...but I looked again, and it still says ecm-ign which is what I gave you the info on before
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here is the correct diagram....see if it pops when the module is disconnected as well
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Awesome diagram. Pretty basic! Thanks. I'll check it out
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ok ok, so apparently my knock gauge was the problem. The signal wire from the knock gauge I was running into the purple and black wire. The connection was fine, but a bit of the wire was exposed. Idk if the signal wire from the knock gauge was pinched or what, but after eliminating the splice between the signal wire from knock gauge to the ignition wire, all was well. :cheers:
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Dunno how easy we are going to let you off, guy_who_makes_ harness_for_a_ living
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LMAO!!!!!!!!!!!! I dont make harnesses for a living. Lol. There is no excuse for it though. :(