Low Voltage, belt slipping? What other causes?

Yellow302

Member
Mar 2, 2003
789
2
19
NJ
So here is my setup.

All new grounds and power lines.
New altenator.
New battery w/terminals.
Old belt. 8 years old
Old tensioner. 8 years old

After rebuilding the whole engine (that sat for three years)
The car was giving massive whine / chatter up front like a bad pully or something. I would spray it with some belt dressing and everything would go away for a few min then come back.
But the voltage was pegged perfect on R in normal.

I installed new headlights roxim or something like that. Which required me tapping into power from the fog light cabels, i belive. Everything was done perfectly and the head lights work great.
Now it is also colder out here in NJ being winter and all.

My sympoms now only exist when the car is warmed up (with headlights on or off). The voltage metter drops down to NO in normal and my temp guage spikes upward, not fullying but it shows that its 50 deg hotter than it really is. Voltage pops back to normal then the temp guage goes back down to a normal range.

When the car is on and cold it runs fine with the headlights on or off, makes no difference.

I have changed the battery terminals with brass instead of lead, (lead wasn't really locking on)
I have a new belt waiting to be installed this weekend.

Any other suggestions on what to look for with this issue? Please help :)
 
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Does this coincide with the fan coming on?

If you have a DMM, I'd use that for testing purposes. The gauge is too useless (esp since you might have a ground issue). If we knew exactly what your voltage was, that would help.

Definitely swap that belt in. Dressings do more harm in the long-term than good and 8 years is a ton of time to get out of an aftermarket belt (if it's not EPDM). You really need a belt gauge to tell the condition because newer high-end belts generally don't crack like they used to (neoprene does, EPDM does not). If worn, that could definitely lead to some slippage.

Not much help there but we'll get it figured out.
 
Does this coincide with the fan coming on?

If you have a DMM, I'd use that for testing purposes. The gauge is too useless (esp since you might have a ground issue). If we knew exactly what your voltage was, that would help.

Definitely swap that belt in. Dressings do more harm in the long-term than good and 8 years is a ton of time to get out of an aftermarket belt (if it's not EPDM). You really need a belt gauge to tell the condition because newer high-end belts generally don't crack like they used to (neoprene does, EPDM does not). If worn, that could definitely lead to some slippage.

Not much help there but we'll get it figured out.

Ok, ill swap the belt today and get it back up to operating temp and see if it happens again.
 
12-2-2012
So the belt I got was way to small. 87 inches.
The one I had on there was 95 inches. I bought a 94 inch and having it delivered.

Update on symptoms.
The voltage is bouncing cold and at any rpm now.

This should narrow my issue down to the voltage regulator on the altenator and or the wires that go into it.
I have ordered two new plugs that go into the voltage regulator. (both clips are broken on the plugs)
I did rewire and lenghten the green and yellow wires because my altenator is relocated due to the super charger.

How and what can I test now?
 
What is the actual voltage fluctuation (measured with a DMM)?

The regulator is likely to be the issue. You can take the alt to be bench tested if you want.
 
Update 12-8-2012
I installed a new belt. (fixed my squeak problem)
Replaced fuses. I used alot of di electric grease when I installed/replaced the fuse.
- Could using too much cause a lack of connection?

During my replacement of the fuses I used electric cleaner and fresh fuses.
The problem is better but not a 100%
I belive I should clean the fuse block more since I saw an improvement after replacing the fuse.
How / what can I clean those contacts with?
 
Unless your fusebox gets really wet (it should not), I would not use dielectric grease liberally at all. A dielectric is non-conductive so don't go nuts with it.

If you really think that cleaning the fusebox contacts is helping, I'd want to test voltage on a given fuse before and after cleaning to note the change in voltage. Unless there's visible corrosion on the contacts (or you see a marked change in voltage - say 0.10V or more), I would not expect much of a change to occur from cleaning (the car running better might be coincidence).

I've used jewelers screwdrivers to scrape dirty fuse contacts.
 
I can use a baby screw driver to clean it up. I will also do the full testing over xmas break.
I found the proper steps to test and replace if need be.
I will also have to check ground wires as well (even though they are new)
 
Tested out everything, everything looks ok.
Worked for about 5 min while driving perfect, I mean dead center fan on lights on radio on.

Problem, I have a paxton novi 2000, so the altenator is relocated to the bottom left of the car.

There is an Oil drain that goes from the super charger into the oil pan. This is leaking onto the altenator and I am almost certain it is getting inside the housing.

Could this be why when its dry from sitting over night it is perfect. then as the car warms up (oil dripping in) causing the internal contacts to not fuction correctly. But the next day work perfect again until warm.

I will be fixing that oil leak and wiping everything up that I can see. Is it safe to spray electrical cleaner into the altenator to aid in the oil removal?
 
In the meantime, can you install a basin of some sort above the alternator to help catch the oil? It's tough to say if this is causing the issue unless oil is really pouring in there. I think you'll just have to find a way to keep the oil out and see. It is promising that the alt does well initially every time you start it up.
 
In the meantime, can you install a basin of some sort above the alternator to help catch the oil? It's tough to say if this is causing the issue unless oil is really pouring in there. I think you'll just have to find a way to keep the oil out and see. It is promising that the alt does well initially every time you start it up.

It will be an easy fix. just undo clamp, slide hose down, tighten clamp. Job complete.

Just incase of any spillage I can throw a plastic bag over the atl.

Its just so damn cold to do any work this time of year, it sucks!
 
Just as the title says.
I am getting a bad hum or buss through the speakers.

I recall a grey connector by the coil being involved with this? Correct me if I am wrong. Would like to get rid of the annoyance.

Thanks!
 
Just as the title says.
I am getting a bad hum or buss through the speakers.

I recall a grey connector by the coil being involved with this? Correct me if I am wrong. Would like to get rid of the annoyance.

Thanks!


I combined these two threads but for a reason. I've read through both of them and I'll bet a dollar that they are related.

With all the part and wire replacements, it appears sir, that you have a stray voltage problem somewhere. It is likely a ground wire or cable and also very likely that it somewhere behind your dash. I've run across similar sets of symptoms probably half a dozen times or more. I had to chase of these gremlins down in my own car several years ago and it turned out to be a small ground strap under the dash. This strap was was the ground for much of the goings on in the instrument cluster and stereo chassis. I had mistakenly relocated the ground that was supposed to be going from the dash framework to the car chassis, and installed it so that it ended up going from the dash framework back to the dash. :(

It took me some time to figure out what had happened. The lack of this one ground caused all kinds of stray voltage problems. The various systems in the car were using every path it could find (power wires, antenna wires, etc.) to find a path to ground. Caused all kinds of weirdness in the audio system as well flaky and intermittent results from my gauge cluster.

Now your problem can just as as easily be a ground or incorrectly mounted power wire under the hood too. So go back through and check all of the things. It was helpful for me to start pulling fuses from the panel, one by one to help find the power source. Once found, I started looking more closely at that system and found the misplaced ground.

Good luck and... if you're handy with a probe and multi-meter, it can help you out a lot.
 
I combined these two threads but for a reason. I've read through both of them and I'll bet a dollar that they are related.

With all the part and wire replacements, it appears sir, that you have a stray voltage problem somewhere. It is likely a ground wire or cable and also very likely that it somewhere behind your dash. I've run across similar sets of symptoms probably half a dozen times or more. I had to chase of these gremlins down in my own car several years ago and it turned out to be a small ground strap under the dash. This strap was was the ground for much of the goings on in the instrument cluster and stereo chassis. I had mistakenly relocated the ground that was supposed to be going from the dash framework to the car chassis, and installed it so that it ended up going from the dash framework back to the dash. :(

It took me some time to figure out what had happened. The lack of this one ground caused all kinds of stray voltage problems. The various systems in the car were using every path it could find (power wires, antenna wires, etc.) to find a path to ground. Caused all kinds of weirdness in the audio system as well flaky and intermittent results from my gauge cluster.

Now your problem can just as as easily be a ground or incorrectly mounted power wire under the hood too. So go back through and check all of the things. It was helpful for me to start pulling fuses from the panel, one by one to help find the power source. Once found, I started looking more closely at that system and found the misplaced ground.

Good luck and... if you're handy with a probe and multi-meter, it can help you out a lot.

I did have to replace the headlight lamp switch and wiring. I was very carefull and used solder and heatshrink tube.

I could look for this group wire under the dash. Can you point me in the right direction? Under the dash, behind the cluster guage?

I have a brand new multi meter guage which is helping me rule things out.

All of my power and main grounds have checked out.

I am thinking there is a ground cable for the fuse box that bolts to the inner fender if I am not mistaken?
 
I did have to replace the headlight lamp switch and wiring. I was very carefull and used solder and heatshrink tube.

I could look for this group wire under the dash. Can you point me in the right direction? Under the dash, behind the cluster guage?

I have a brand new multi meter guage which is helping me rule things out.

All of my power and main grounds have checked out.

I am thinking there is a ground cable for the fuse box that bolts to the inner fender if I am not mistaken?


Without being underneath your dash to see the things that you can see, there's no way that I can think of to get you any closer than I already have. I might start with the things that you mentioned in your first post on this subject:

All new grounds and power lines.
New altenator.
New battery w/terminals.

Stray voltage can use ANY wiring in your vehicle in order to find a path to ground when the normal ground is not present. Even power supply wires can be used as a ground if voltage in that wire is less than the voltage that is trying to find a path to ground.

Also.... ensure you are using resistor type spark plugs and not off-road units. Leaking spark plug wires, a noisy or improperly grounded coil, weak ground to/from alternator, wiring to/from dizzy... the list can go on and on.

Remove, clean, and reinstall all of the grounds you messed with before. Ensure they're connected to the correct location and that you've not created a loop-back someplace.
 
Good call to combine the threads. :nice:

There's a stereo ground behind the driver's kick panel that's known for allowing whine.

Given the issues, you might want to first check for ripple with the car running. Anything over half of a volt is not good. Set your meter to AC Voltage and put the red lead on the output lug and the ground on the alt case.