ok, while driving my dash will keep cutting out (mileage cluster goes dead, gauges won't work), but it seems to only happen when i go WOT. has anyone else had this issue? i know its electrical but i don't really know where to start looking. checked my grounds and they all looked good. just replaced the alternator bc the old one went bad. could a low battery cause this? any help or advice is appreciated.
dash going haywire
03SXT
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ok, while driving my dash will keep cutting out (mileage cluster goes dead, gauges won't work), but it seems to only happen when i go WOT. has anyone else had this issue? i know its electrical but i don't really know where to start looking. checked my grounds and they all looked good. just replaced the alternator bc the old one went bad. could a low battery cause this? any help or advice is appreciated.
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anybody? could really use some help. list of things i've done so far:
1) checked all grounds, all connectors, looked for loose wires, checked all fuses. saw nothing out of normal, cleaned my grounds, and replugged all connections.
2) had alternator tested and it was bad, replaced it, had same issue, the replacement tested bad, they exchanged it, i'm still having the same problem. voltage stays down in the red and flutters very little, gas gauge does the same, when i get to about 4K rpm my odometer goes out and the gas, voltage, and oil pressure gauges go dead. speedo and tach seem fine but they did flutter before also, just not anymore for some reason.
3) unplugged pcm, checked pins, checked for cracked wires in the harness, etc. the pcm is a brand new reman. one i bought a couple weeks ago. the truck runs fine other than this issue and when the gauges and odometer die the truck will act like it misses as they flicker.
4) replaced battery. no improvement, have tested both and they are both good.
5) replaced TPS. still no improvement although it did idle smoother, but interior lights and gauges still flicker at high rpm.
i've googled and searched and came up with a few possibilities but no results were posted and it usually is a dead end for more info or very vague on symptoms so hard to really tell if it relates to my issue. i'm at a loss for where to check now, any advice or info is greatly appreciated! thanks.
1) checked all grounds, all connectors, looked for loose wires, checked all fuses. saw nothing out of normal, cleaned my grounds, and replugged all connections.
2) had alternator tested and it was bad, replaced it, had same issue, the replacement tested bad, they exchanged it, i'm still having the same problem. voltage stays down in the red and flutters very little, gas gauge does the same, when i get to about 4K rpm my odometer goes out and the gas, voltage, and oil pressure gauges go dead. speedo and tach seem fine but they did flutter before also, just not anymore for some reason.
3) unplugged pcm, checked pins, checked for cracked wires in the harness, etc. the pcm is a brand new reman. one i bought a couple weeks ago. the truck runs fine other than this issue and when the gauges and odometer die the truck will act like it misses as they flicker.
4) replaced battery. no improvement, have tested both and they are both good.
5) replaced TPS. still no improvement although it did idle smoother, but interior lights and gauges still flicker at high rpm.
i've googled and searched and came up with a few possibilities but no results were posted and it usually is a dead end for more info or very vague on symptoms so hard to really tell if it relates to my issue. i'm at a loss for where to check now, any advice or info is greatly appreciated! thanks.
The lights should not be flickering. If the alternator is good, including the rectifiers, then I'd be thinking PCM as it is the voltage regulator. Unless you have another bad alternator.
Where'd you get the alternator?
What are you getting for voltage, engine off, and engine on? Then load it up with the heater on high/lights/etc. What is it now? Bring the rpms up to about 1500 and check again. Use a digital meter, not the one in the dash.
You're not getting a "no bus" message? I'm still thinking that something is up with the PCM.
Where'd you get the alternator?
What are you getting for voltage, engine off, and engine on? Then load it up with the heater on high/lights/etc. What is it now? Bring the rpms up to about 1500 and check again. Use a digital meter, not the one in the dash.
You're not getting a "no bus" message? I'm still thinking that something is up with the PCM.
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i'm pretty sure this alternator is ok. i tested the output of it and according to my multi-meter its showed around 15 volts coming off the bolt on the back of it. that was at idle. i'll have to test under load but for idle that should be about right IIRC. its just a stock replacement reman. unit from advanced auto.
i'm not getting any codes or no bus messages. i tried to do the cluster check also and it didn't show any codes either. i'm leaning towards computer also, which really sucks bc i just got it a few weeks ago. on the upside, it is covered by warranty so i would only have to pay to ship it out for inspection, which i hate bc of the down-time. i'm really trying to exhaust all possible causes before i have to do that, but if i don't figure it out by tomorrow evening i'm gonna make the call i guess. i've spent $300 since i put the 408 back in just a few weeks ago, its nickel and diming me to death.
edit: also, i can drive it for a few minutes (just around the yard) and it will start to sputter and then die. sometimes it doesn't want to start back up and sometimes it will fire right back up immediately. :huh:
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I had a similar issue and I had wires broken loose at the main connector to the key switch on the underside of the steering column.
Also .... have you tried another set of gauges to see if it could be a problem with the gauges themselves?
Also .... have you tried another set of gauges to see if it could be a problem with the gauges themselves?
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i looked well under the dash and around the steering column and didn't see anything abnormal, but i'm still going to pull the dash back and check the connector to the cluster coming from the wiring harness to see if its pulled loose or something. i don't have access to any other gauges, the one from my 03 won't work. i wouldn't be surprised if i overlooked something though, the previous owners turned the dash into a complete birds nest of wiring. i'm going to double check all the splices and stuff they did to make sure.
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damn, i still havent got this figured out yet. i managed to barely make it a few miles up the road to advanced auto to check codes and it only had one: p1492, which is battery voltage/ambient temperature too high. so i went and snatched the BTS off my other truck and plugged it up, same thing is still happening. i barely got home, it was sputtering and would jump lean trying to die on me the whole way home, sometimes sounded like the engine was off then it would catch spark or something and come back to life. got to my road and it cut off completely and i just did have enough speed to get to my house and up the driveway.
i have uploaded a video of what its doing. take a look and any advice is greatly appreciated! i'm about ready to set this bitch on fire and collect insurance.
edit: also, i have a relocated battery, its in the bed. i have my methanol tank sitting in the battery tray. could this cause the problem? seems to me it would read it being cooler and would adjust the voltage up. i'm about to go pull the battery tray out and check all the wiring from that sensor back through the harness. i may also try a ignition off leak detection to see if some voltage is leaking out somewhere while the truck sits, although i don't think this is the case bc the battery isn't being drained that i can tell. i'm thinking i'll probably mess with it through the weekend and if nothing changes i'm going to send the pcm out for inspection to be sure the voltage regulator isn't fried. seems very unlikely to me though, i mean its a fresh pcm and usually its hard to fry it from what i read.
i have uploaded a video of what its doing. take a look and any advice is greatly appreciated! i'm about ready to set this bitch on fire and collect insurance.
edit: also, i have a relocated battery, its in the bed. i have my methanol tank sitting in the battery tray. could this cause the problem? seems to me it would read it being cooler and would adjust the voltage up. i'm about to go pull the battery tray out and check all the wiring from that sensor back through the harness. i may also try a ignition off leak detection to see if some voltage is leaking out somewhere while the truck sits, although i don't think this is the case bc the battery isn't being drained that i can tell. i'm thinking i'll probably mess with it through the weekend and if nothing changes i'm going to send the pcm out for inspection to be sure the voltage regulator isn't fried. seems very unlikely to me though, i mean its a fresh pcm and usually its hard to fry it from what i read.
Something is going on with your electrical system. The lights and gauges should not be following the rpm like that at all.
The PCM starts to act really weird when the voltage gets low.
What's the voltmeter reading, certainly less than 14, is it even out of the red? Put a real meter on it and with some actual numbers.
The PCM starts to act really weird when the voltage gets low.
What's the voltmeter reading, certainly less than 14, is it even out of the red? Put a real meter on it and with some actual numbers.
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the numbers on the volt gauge are 8 (red), 14 (middle) and 18. it has always ran at around 14-15 normally when i had my 360 in there. so you are saying read the voltage coming off the post on the back of the alternator right?
Read the voltage at the battery. It should, better, be the same as at the alternator output. Watch the voltage as you give it gas. It'll rise a bit, that's normal, but you should be around 14 at idle, maybe up to 14.6 at rpm.
Watching the video, the voltmeter is very low, barely off the peg. The PCM can't handle voltages that low.
Watching the video, the voltmeter is very low, barely off the peg. The PCM can't handle voltages that low.
It does appear that the PCM is getting low voltage.
I know it sounds really basic, but make sure all your grounds are good, clean, and tight. Also, with the engine swap, make sure you have a good ground between the engine and frame, and (of course) the battery to the frame.
I have had grounds that looked good, but when they were removed, there was corrosion between the ground and the frame.
Also, since you have relocated the battery, is the ground going to a *clean* spot on the frame (i.e. grind off the paint)?
On your old engine, there was a bundle of ground wires that were bolted to the front of the engine, near where the coil was located. If these are not good / tight / clean, all kinds of weird things can happen. This ground feeds many items, including part of the ignition circuit.
If all of the above checks out, move to the positive side. Clean the alternator terminal and ring terminal that bolts to the alternator.
In two (of three) of my Mopar vehicles, gauges acting weird are tied to low voltage...caused by bad batteries, or grounding.
I know it sounds really basic, but make sure all your grounds are good, clean, and tight. Also, with the engine swap, make sure you have a good ground between the engine and frame, and (of course) the battery to the frame.
I have had grounds that looked good, but when they were removed, there was corrosion between the ground and the frame.
Also, since you have relocated the battery, is the ground going to a *clean* spot on the frame (i.e. grind off the paint)?
On your old engine, there was a bundle of ground wires that were bolted to the front of the engine, near where the coil was located. If these are not good / tight / clean, all kinds of weird things can happen. This ground feeds many items, including part of the ignition circuit.
If all of the above checks out, move to the positive side. Clean the alternator terminal and ring terminal that bolts to the alternator.
In two (of three) of my Mopar vehicles, gauges acting weird are tied to low voltage...caused by bad batteries, or grounding.
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voltage at the post on the alternator at idle is around 15.6-15.7. battery voltage at idle is 15.4-15.5. so it seems that it is charging, so the alternator must be ok. i can't give it gas right now, neighbors are probably asleep or trying to go to sleep and my truck is loud as hell lol. i'll have to check the voltages with gas tomorrow.
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i checked the grounds but i will go over them all again tomorrow just to make absolutely sure i didn't miss any. the alternator is brand new so its clean and the cable running to it from the distribution box is fairly new, its terminals are clean.
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