Car Stall when when I turnon the headlights

Gotta love that wiring . . .
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ronj81

Car Stall when when I turnon the headlights

Post by ronj81 »

Hi,

I have a 1981 Fiat Spider. My car stall when I turn on the headlight. I played around with it by turning on the parking light and the car still run with no problem - but when I turn on the headlights the battery redlight indicator on the dash lit and few second later the car stall. One night I had to drive home with only parkling lights on...
Please help... :evil:
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81SPIDERMATT
Posts: 1239
Joined: Mon Oct 11, 2010 5:10 pm
Your car is a: 1981 spider 2000
Location: FORT COLLINS, CO

Re: Car Stall when when I turnon the headlights

Post by 81SPIDERMATT »

ok .... had a similar problem... very similar.... others will chime in on testing volts at the battery with car off and with car running.... these are needed readings to diagnose the problem.... loose belt .... bad alternator.... bad voltage regulator are all possible culprits..... local auto parts store can hook up a gizmo that can help a lot also to isolate certain faults in the system.... for me it was a bad voltage regulator.... i also have an 81 and the regulator is actually inside the alternator...i think it was 25 bucks and all was good again..... good luck... and post up some voltage readings if you get a chance
ronj81

Re: Car Stall when when I turnon the headlights

Post by ronj81 »

I have found the corporate of the problem, it something to with my key ignition switch. I remove the yellow wire and problem and place it in the acc. Now problem is every time i remove the key the red light turn on "battery indicator" . If i choose to get rig of the red light i have leave the key on acc switch but i cant remove the key. Ignition wiring is all jack up.
ronj81

Re: Car Stall when when I turnon the headlights

Post by ronj81 »

I may have spoke to soon... The car still stall but I have narrow it down. It only stall when it overheat or above 210 and when the radiator fan kicks in. She would start right back up when I start it but it dies down again until the car cools off. Any suggestion to this head scratching problem... Thanks
TX82FIAT
Posts: 1814
Joined: Mon May 03, 2010 11:04 am
Your car is a: 82 Fiat Spider 2000 CSO
Location: San Antonio

Re: Car Stall when when I turnon the headlights

Post by TX82FIAT »

You could have a couple issues at the same time makeing it harder to diagnose. First, did you test the voltage with the car on and the car off? Second, is it the original ignition switch? the voltage test is required to see if you have a charging issue or a battery issue. The fan does not run through the ignition switch like almost everything else including the headlights on a stock set up. If your alternator is not charging the system for a variety of reasons (regulator, grounds, lose wire, belt, age) then your battery is running down and is more prone to fail. Does you battery hold a charge? A voltage meter is only a couple bucks at harbor freight.

I'm going to catch hell for this one.... In the abscense of any testing equiptment, you could hook a running car up to the spider using jumper cables the same way you would jump start the car. start the spider up and let it run for a few heating cycles to see if your fan cause a stall and your headlights work.

Most likely it is something in the charging system (bettery or alternator) however, the possability exists that you have an ignition switch issue as well.
Buon giro a tutti! - enjoy the ride!

82 Fiat Spider 2000
03 BMW M3
07 Chevy Suburban
ronj81

Re: Car Stall when when I turnon the headlights

Post by ronj81 »

TX82FIAT wrote:You could have a couple issues at the same time makeing it harder to diagnose. First, did you test the voltage with the car on and the car off? Second, is it the original ignition switch? the voltage test is required to see if you have a charging issue or a battery issue. The fan does not run through the ignition switch like almost everything else including the headlights on a stock set up. If your alternator is not charging the system for a variety of reasons (regulator, grounds, lose wire, belt, age) then your battery is running down and is more prone to fail. Does you battery hold a charge? A voltage meter is only a couple bucks at harbor freight.

I'm going to catch hell for this one.... In the abscense of any testing equiptment, you could hook a running car up to the spider using jumper cables the same way you would jump start the car. start the spider up and let it run for a few heating cycles to see if your fan cause a stall and your headlights work.

Most likely it is something in the charging system (bettery or alternator) however, the possability exists that you have an ignition switch issue as well.

I measured the battery from the alternator terminal "engine off" and i am getting 12.47V , then i measure with it again at the same point "engine on" and i am getting 14.61V.

With that, i can eliminate the charging system. any other possible place to look at? The ignition switch is not original.
TX82FIAT
Posts: 1814
Joined: Mon May 03, 2010 11:04 am
Your car is a: 82 Fiat Spider 2000 CSO
Location: San Antonio

Re: Car Stall when when I turnon the headlights

Post by TX82FIAT »

Try measuring it from the battery terminals with the engine on and off. The 14.61V at the alternator terminals is very strong with engine on. I would verify that there is not too much of a fall off from the alternator through the ground to the negative terminal. If you do not have an original switch that could be part of the problem with the headlights as i am told the switches made in china and russia are not very good quality.

Hopefully you will not need to start testing circuits to find the week link.
Buon giro a tutti! - enjoy the ride!

82 Fiat Spider 2000
03 BMW M3
07 Chevy Suburban
ronj81

Re: Car Stall when when I turnon the headlights

Post by ronj81 »

TX82FIAT wrote:Try measuring it from the battery terminals with the engine on and off. The 14.61V at the alternator terminals is very strong with engine on. I would verify that there is not too much of a fall off from the alternator through the ground to the negative terminal. If you do not have an original switch that could be part of the problem with the headlights as i am told the switches made in china and russia are not very good quality.

Hopefully you will not need to start testing circuits to find the week link.
I measured the voltage on the battery terminal "engine off" 12.3V measure it again on the same terminal "engine on" 13.9V.
TX82FIAT
Posts: 1814
Joined: Mon May 03, 2010 11:04 am
Your car is a: 82 Fiat Spider 2000 CSO
Location: San Antonio

Re: Car Stall when when I turnon the headlights

Post by TX82FIAT »

Well, the good news is that should rule out the battery and the alternator. It does not rule out a voltage regulator or internal voltage regulator just yet. As you turn the lights on the voltage regulator should in teory adjust for the increased demand.
Buon giro a tutti! - enjoy the ride!

82 Fiat Spider 2000
03 BMW M3
07 Chevy Suburban
User avatar
81SPIDERMATT
Posts: 1239
Joined: Mon Oct 11, 2010 5:10 pm
Your car is a: 1981 spider 2000
Location: FORT COLLINS, CO

Re: Car Stall when when I turnon the headlights

Post by 81SPIDERMATT »

TX82FIAT wrote:Well, the good news is that should rule out the battery and the alternator. It does not rule out a voltage regulator or internal voltage regulator just yet. As you turn the lights on the voltage regulator should in teory adjust for the increased demand.

AGREED..... did you do voltage at the battery car running after headlights on,,, fan on ...wipers on and such... either or all ??

also autozone can hook up a tester and tell you quick
ronj81

Re: Car Stall when when I turnon the headlights

Post by ronj81 »

81SPIDERMATT wrote:
TX82FIAT wrote:Well, the good news is that should rule out the battery and the alternator. It does not rule out a voltage regulator or internal voltage regulator just yet. As you turn the lights on the voltage regulator should in teory adjust for the increased demand.

AGREED..... did you do voltage at the battery car running after headlights on,,, fan on ...wipers on and such... either or all ??

also autozone can hook up a tester and tell you quick
Yes, i took measurement "engine on" with highbeam on, radio on, wiper motor on, hazard on, and i am getting 12.6 v - but i can see that the lights dims just a little - my rpm is at 900. i let it run until the cooling fan turn on then the car dies. i start it again leaving everything as is the will not start. raditator fan still on. but when i turn off the headlight and put it on parking light on the car starts. where is this voltage regulator located that was mentioned?
TX82FIAT
Posts: 1814
Joined: Mon May 03, 2010 11:04 am
Your car is a: 82 Fiat Spider 2000 CSO
Location: San Antonio

Re: Car Stall when when I turnon the headlights

Post by TX82FIAT »

On the 81 it should be a small component attached to the alternator not a seperate unit like the old regulators. it hooks on to the alternator with two screws or allen bolts with a circle in the middle and two priongs that reach into the unit. You wont be able to see the metal spring loaded prongs until you take the unit off. Google fiat spider voltage regulator and it should pull up a pic.
Buon giro a tutti! - enjoy the ride!

82 Fiat Spider 2000
03 BMW M3
07 Chevy Suburban
majicwrench

Re: Car Stall when when I turnon the headlights

Post by majicwrench »

Your charging system working fine. It IS NOT your voltage reg giving you issues.
Need to find where the volt is dropping. Start by hooking voltmeter to coil positive, should show system voltage as car is running. Now start turning things on. Voltage should not drop much, never below 12 volts. What does it read when car dies??
Keith
ronj81

Re: Car Stall when when I turnon the headlights

Post by ronj81 »

majicwrench wrote:Your charging system working fine. It IS NOT your voltage reg giving you issues.
Need to find where the volt is dropping. Start by hooking voltmeter to coil positive, should show system voltage as car is running. Now start turning things on. Voltage should not drop much, never below 12 volts. What does it read when car dies??
Keith
Keith, I measured the voltage from the coil terminal, first measurement I place the + probe on the positive side of the coil and place the neg probe on the body of the engine - with engine on. I am getting 12.9 to 13.2V.

Then I measured the voltage again placing the probe on the positive side of coil and place the neg probe on the negative side of the coil - engine on, radio on and head lights on. I am getting a 1.9V - then I turn off the radio and headlight and see if there is any gain the on the voltage. Measurement still at 1.9 to 2.0V between the + and - of the ignition coil.

I am doing doing steps you gave above and I am not done yet but I thought I point out the obvious finding.
ronj81

Re: Car Stall when when I turnon the headlights

Post by ronj81 »

ronj81 wrote:
majicwrench wrote:Your charging system working fine. It IS NOT your voltage reg giving you issues.
Need to find where the volt is dropping. Start by hooking voltmeter to coil positive, should show system voltage as car is running. Now start turning things on. Voltage should not drop much, never below 12 volts. What does it read when car dies??
Keith
Keith, I measured the voltage from the coil terminal, first measurement I place the + probe on the positive side of the coil and place the neg probe on the body of the engine - with engine on. I am getting 12.9 to 13.2V.

Then I measured the voltage again placing the probe on the positive side of coil and place the neg probe on the negative side of the coil - engine on, radio on and head lights on. I am getting a 1.9V - then I turn off the radio and headlight and see if there is any gain the on the voltage. Measurement still at 1.9 to 2.0V between the + and - of the ignition coil.

I am doing doing steps you gave above and I am not done yet but I thought I point out the obvious finding.
Alright, more testing done. I place the +probe on the coil terminal and let the car run, Voltage reads at 13.1 -13.2, I turn on the lights - voltage reads at 13.1, turn on the hazard lights - voltage reads at 13.1, turn on the radio with amp voltage reads at 12.8 - 13.1v - Car Temp reach 210 and the fan kicks in - Voltage went from 13.0V to 11.80 up to 13.V down to 10.8 up 12. V down to 9.8 then the car stalled. When the engine turn off voltage reads at 11.9 as final reading. Its seems like the radiator fan is sucking up all energy of the car...
What is next?
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