Voltage Drop When Blower Motor Is On
02-01-2013, 09:58 PM
#16
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Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
Done this?
Improving the Instrument Panel Ground
The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release ****. The screw will have either a ¼" or 5/16" head on it.
This ground point is responsible for handling the ground circuit for the following items: Dome lamps, Seatbelt and key warning, trans comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.
The problem is that where the ground point is located does not have a good contact with the chassis where the ground should be. The solution is simple.
Make up a jumper wire with #10 gauge wire about 10" long. On one end, crimp on a ¼" round wire terminal. On the other end, crimp on a 3/8" round wire terminal.
Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other.
Look above the driver’s side plastic kick panel just forward of the top of the hood release ****. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely.
**Special note for Comanche owners: Make your jumper wire 12" long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**
Revised 11-29-2011
Improving the Instrument Panel Ground
The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release ****. The screw will have either a ¼" or 5/16" head on it.
This ground point is responsible for handling the ground circuit for the following items: Dome lamps, Seatbelt and key warning, trans comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.
The problem is that where the ground point is located does not have a good contact with the chassis where the ground should be. The solution is simple.
Make up a jumper wire with #10 gauge wire about 10" long. On one end, crimp on a ¼" round wire terminal. On the other end, crimp on a 3/8" round wire terminal.
Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other.
Look above the driver’s side plastic kick panel just forward of the top of the hood release ****. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely.
**Special note for Comanche owners: Make your jumper wire 12" long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**
Revised 11-29-2011
02-01-2013, 10:02 PM
#17
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Year: 1990
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cruiser54 I just installed the ground from the negative battery terminal to the closest 10mm bolt, tightened up the belt, will be working on the cluster ground and will get the engine stud taken care of. Hopefully this is it. Otherwise Ill look more into the link xj guy suggested.
02-09-2013, 07:35 AM
#18
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Year: 1996
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I recently ran into the same problem, the other day I was doing a tune up but the guy at advance auto gave me the wrong rotor and cap, so I did the plugs and wires, would this have an impact on voltage drop? I know it sounds wired or stupid, but it was right after that, also I hit a bump and the relay cluster in the dash under the steering column fell out, could this have stretched or ripped the ground loose? Thanks for any help! Also when the motor is cold, I get a high pitched sound from the engine compartment when I first start it for about 30-50 seconds
02-09-2013, 11:13 AM
#19
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Year: 1990
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Im not quite sure what is going on with your first problem of the voltage drop after you replaced the rotor cap and wires. Have you gotten a volt-ohm meter to test the voltage at the battery to make sure your gauge reading is correct? the low voltage could just be a bad connection between the gauge and the reading point. The second problem with the high whistle sound coming from the engine I have an idea for. Check each bolt holding the intake manifold and exhaust manifold on to make sure they are tight. I recently had a high pitch whistle coming from the engine and it was because a few bolts were loose.
UPDATE: I have put in the grounding wire from the gauge cluster to a bolt on the frame. It wasn't the exact one specified in the article though. I found a bolt that was a bit bigger and was located a little higher and towards the engine from the hood release handle. Along with this I decided to test the voltage at the battery and compare it to what my gauge said. When I had my AC running, KC lights on (2), head lights on, and my aux fan going I got a reading of 13.5 volts at the battery but then at the gauge it said I have around 10-9 volts. So I'm thinking the wire between the gauge and the point where it connects into the electrical system is malfunctioning. Thoughts? anyone know where the battery gauge taps into the electrical system?
UPDATE: I have put in the grounding wire from the gauge cluster to a bolt on the frame. It wasn't the exact one specified in the article though. I found a bolt that was a bit bigger and was located a little higher and towards the engine from the hood release handle. Along with this I decided to test the voltage at the battery and compare it to what my gauge said. When I had my AC running, KC lights on (2), head lights on, and my aux fan going I got a reading of 13.5 volts at the battery but then at the gauge it said I have around 10-9 volts. So I'm thinking the wire between the gauge and the point where it connects into the electrical system is malfunctioning. Thoughts? anyone know where the battery gauge taps into the electrical system?
02-09-2013, 02:07 PM
#20
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Im not quite sure what is going on with your first problem of the voltage drop after you replaced the rotor cap and wires. Have you gotten a volt-ohm meter to test the voltage at the battery to make sure your gauge reading is correct? the low voltage could just be a bad connection between the gauge and the reading point. The second problem with the high whistle sound coming from the engine I have an idea for. Check each bolt holding the intake manifold and exhaust manifold on to make sure they are tight. I recently had a high pitch whistle coming from the engine and it was because a few bolts were loose.
UPDATE: I have put in the grounding wire from the gauge cluster to a bolt on the frame. It wasn't the exact one specified in the article though. I found a bolt that was a bit bigger and was located a little higher and towards the engine from the hood release handle. Along with this I decided to test the voltage at the battery and compare it to what my gauge said. When I had my AC running, KC lights on (2), head lights on, and my aux fan going I got a reading of 13.5 volts at the battery but then at the gauge it said I have around 10-9 volts. So I'm thinking the wire between the gauge and the point where it connects into the electrical system is malfunctioning. Thoughts? anyone know where the battery gauge taps into the electrical system?
UPDATE: I have put in the grounding wire from the gauge cluster to a bolt on the frame. It wasn't the exact one specified in the article though. I found a bolt that was a bit bigger and was located a little higher and towards the engine from the hood release handle. Along with this I decided to test the voltage at the battery and compare it to what my gauge said. When I had my AC running, KC lights on (2), head lights on, and my aux fan going I got a reading of 13.5 volts at the battery but then at the gauge it said I have around 10-9 volts. So I'm thinking the wire between the gauge and the point where it connects into the electrical system is malfunctioning. Thoughts? anyone know where the battery gauge taps into the electrical system?
I would unplug, clean, and refresh the one behind the battery.
One reason I wrote this:
I suggest unplugging EVERY electrical connection in the engine bay you can find, whether engine related or not, and spraying it out with a good electronics cleaner, visually inspecting the terminals making sure they haven’t retracted into the plastic holder, and then plugging it back together. There’s a critical 10-pin connector for the front lighting system located in front of the air cleaner and behind the left headlight assembly. Don’t miss that one
. Also be sure that the connectors to the ballast resistor mounted near the air cleaner housing are clean and tight.
ALL of the relays should be removed, the terminals wire-brushed until shiny, and the receptacles sprayed out with contact cleaner. Then plug them back in. I do this on every Renix Jeep I purchase or work on for someone else.
Revised 07/23/2012
02-09-2013, 02:34 PM
#21
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Year: 1996
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Thank you ill give it a try, mine drops to about 10-12 I'm guessing bc as you the gauge is 9 then 14, I'll put a mete on it tomorrow at work, thx again
02-09-2013, 02:36 PM
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02-09-2013, 09:45 PM
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02-09-2013, 10:13 PM
#24
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02-10-2013, 01:43 PM
#25
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so I followed the tan wire best I could and found a gray colored connector right behind the battery. I pulled it apart, got some electric connector cleaner spray and put it back together. It really hasn't changed anything. At first it was working great, but then the gauge started acting up again. I did turn on all my electric accessories and let the engine idol. One of the upgrades I've done is a manual override switch for the aux electric fan, which I had turned on. Randomly while I had all the electric goodies on and the engine idling, I would hear the rpm of the aux electric fan rise (the sound the fan made went to a higher pitch) and the electric gauge in my XJ went up. Then dropped down again along with the sound of the aux fan. The other thing observed was when I had all my accessories on (head lights, KC's, aux electric fan) the gauge was at 11-12 and the battery was at 14.3 My main question is, should I now unplug the BIG connector right by the master cylinder and clean it out along with pulling the gauge cluster and cleaning that connection? and any idea to why my fan would randomly get more amps so it could rev to a higher rpm? Again thanks for all your input so far.
02-10-2013, 02:01 PM
#26
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so I followed the tan wire best I could and found a gray colored connector right behind the battery. I pulled it apart, got some electric connector cleaner spray and put it back together. It really hasn't changed anything. At first it was working great, but then the gauge started acting up again. I did turn on all my electric accessories and let the engine idol. One of the upgrades I've done is a manual override switch for the aux electric fan, which I had turned on. Randomly while I had all the electric goodies on and the engine idling, I would hear the rpm of the aux electric fan rise (the sound the fan made went to a higher pitch) and the electric gauge in my XJ went up. Then dropped down again along with the sound of the aux fan. The other thing observed was when I had all my accessories on (head lights, KC's, aux electric fan) the gauge was at 11-12 and the battery was at 14.3 My main question is, should I now unplug the BIG connector right by the master cylinder and clean it out along with pulling the gauge cluster and cleaning that connection? and any idea to why my fan would randomly get more amps so it could rev to a higher rpm? Again thanks for all your input so far.
02-10-2013, 02:02 PM
#27
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Year: 1989 xj sport 2dr
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Engine: 12 hole bosch Injectors
so I followed the tan wire best I could and found a gray colored connector right behind the battery. I pulled it apart, got some electric connector cleaner spray and put it back together. It really hasn't changed anything. At first it was working great, but then the gauge started acting up again. I did turn on all my electric accessories and let the engine idol. One of the upgrades I've done is a manual override switch for the aux electric fan, which I had turned on. Randomly while I had all the electric goodies on and the engine idling, I would hear the rpm of the aux electric fan rise (the sound the fan made went to a higher pitch) and the electric gauge in my XJ went up. Then dropped down again along with the sound of the aux fan. The other thing observed was when I had all my accessories on (head lights, KC's, aux electric fan) the gauge was at 11-12 and the battery was at 14.3 My main question is, should I now unplug the BIG connector right by the master cylinder and clean it out along with pulling the gauge cluster and cleaning that connection? and any idea to why my fan would randomly get more amps so it could rev to a higher rpm? Again thanks for all your input so far.
Ive got a 3 foot 3/8 extension and a 3 1/2 socket ....
02-10-2013, 07:11 PM
#30
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Cruiser54 I have sprayed out and cleaned these connectors
freegdr Here's a pic of the connector I was talking about. Its on the drivers side of the Jeep by the brake master cylinder.
UPDATE: When I started my XJ up again I noticed it was going up and down in volts so I measured it. It was going from 16.1 volts to 14.5 randomly. Usually with half a minute to a minute after it jumped up to 16.1 volts it would jump back to 14.5 This happened only during warm up and when I pulsed the accelerator. I'm not sure why this would happen. I've never delt with a problem with too much voltage. Ill definitely be hitting the books!
freegdr Here's a pic of the connector I was talking about. Its on the drivers side of the Jeep by the brake master cylinder.
UPDATE: When I started my XJ up again I noticed it was going up and down in volts so I measured it. It was going from 16.1 volts to 14.5 randomly. Usually with half a minute to a minute after it jumped up to 16.1 volts it would jump back to 14.5 This happened only during warm up and when I pulsed the accelerator. I'm not sure why this would happen. I've never delt with a problem with too much voltage. Ill definitely be hitting the books!