Guages dim on hard acceleration
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From: Southern Illinois
Guages dim on hard acceleration
Hey guys,
I recently finished up a spark plug tune up which landed costing more due to new fuel injectors being added to the equation. Not that the tune up matters to my point, I have been driving my vehicle all over creation just making sure everything is solid before I take it on a couple hundred mile road trip in a month from now. Last night on my way home it was late and I had the road all to myself so I decided to open it up for a second to see how my vehicle responded to an instant jab to the gas. So the pedal goes down pretty far, RPMs shoot up, and transmission downshifts to keep up with my demand. In doing this I notice my entire instrument cluster went dim the entire time the load was applied. As soon as I backed off and tranny slipped into fourth, the dimness disappeared and all was back to normal.
Now, I've driven a lot of different vehicles and I can't for the life of me recall any of the others diming as well. Is this normal or is this one of those typical Ford symptons?
97 XLT 4x4 5.4L
I recently finished up a spark plug tune up which landed costing more due to new fuel injectors being added to the equation. Not that the tune up matters to my point, I have been driving my vehicle all over creation just making sure everything is solid before I take it on a couple hundred mile road trip in a month from now. Last night on my way home it was late and I had the road all to myself so I decided to open it up for a second to see how my vehicle responded to an instant jab to the gas. So the pedal goes down pretty far, RPMs shoot up, and transmission downshifts to keep up with my demand. In doing this I notice my entire instrument cluster went dim the entire time the load was applied. As soon as I backed off and tranny slipped into fourth, the dimness disappeared and all was back to normal.
Now, I've driven a lot of different vehicles and I can't for the life of me recall any of the others diming as well. Is this normal or is this one of those typical Ford symptons?
97 XLT 4x4 5.4L
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From: Southern Illinois
Didn't see a battery light although I have been watching. As for the belt tension, I will check that out as soon as the weather clears up.
The other thing I thought of was that I had the brights on so I don't know if I was pulling too much stress on the system at the time.
The other thing I thought of was that I had the brights on so I don't know if I was pulling too much stress on the system at the time.
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From: Tualatin, OR
It shouldn't make a difference having the brights on. Check alternator belt and then have a load test done on the charging system. Most places do it for free. It will either be a bad alternator or battery or both. Both are easy to swap out.
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JL
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Thanks for the replies. Had the alternator checked out and its fine (according to my auto parts guy) and the battery is brand new so I can rule that out of the equation (2 months since install). Also, I have not seen a battery light come on at all - even under that hard acceleration I did. I will get around to checking the tensioner sometime soon. I had a problem with temperature control that I had to address first. It could be belts as there is 108,000 on it and I know they are original.
On the 5.4Ls if the tensioner isn't applying enough force, is it as simple as buying a new one and bolting it on to the motor? I know on my old Chevy that's all that I had to do.
As always thanks for the insight. I'm learning quickly.
On the 5.4Ls if the tensioner isn't applying enough force, is it as simple as buying a new one and bolting it on to the motor? I know on my old Chevy that's all that I had to do.
As always thanks for the insight. I'm learning quickly.
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From: SE Texas
It could be the belt,but I find it VERY unlikely that it's the tensioner. That '98 F150 is Dad's now,and with 250K+ miles on it-the truck still has the original tensioner. My Tbird sees 7K rpms shifts at the track,and it's still got the original tensioner on it with just a bit over 250K miles as well. Neither have any issues with belt slippage.
JL
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On my '98 F150, the alternator was perfect at low RPM. It would test good at low RPM. The brushes were worn, and the springs that hold them against the slip rings had just enough tension to hold them solid up to around 3800 rpms. At that point the lights would dim, and at 5000rpms the battery light would come on. Changed the brushes($6 and a few minutes of my time), and fixed it. The truck had 107K miles on it when I got it, and this was the first thing I did.
It could be the belt,but I find it VERY unlikely that it's the tensioner. That '98 F150 is Dad's now,and with 250K+ miles on it-the truck still has the original tensioner. My Tbird sees 7K rpms shifts at the track,and it's still got the original tensioner on it with just a bit over 250K miles as well. Neither have any issues with belt slippage.
JL
It could be the belt,but I find it VERY unlikely that it's the tensioner. That '98 F150 is Dad's now,and with 250K+ miles on it-the truck still has the original tensioner. My Tbird sees 7K rpms shifts at the track,and it's still got the original tensioner on it with just a bit over 250K miles as well. Neither have any issues with belt slippage.
JL
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I take it that changing the brushes are pretty easy then. I know the alternator is right on top, so you slip the belt off, disconnect the alternator, crack it open and swap? To me that sounds like an easy/cheap enough task to see if that fixes my problem. Heck if I buy an alternator, I know that's at least $100 anymore.
JL
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JL
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