I am just trying to help out a friend that is not full of pocket cash with a 2001 Solera 4 banger. They have had a problem with the gauge and power windows fuse blowing and then they would stop the car and not be able to start it again until it got jumped. I read on the forum that the same fuse that controls the gauges and the window also controls the alternator, although I could not find documentation on that. Apparently if that fuse does control the alternator then when it blows while the are driving the car is now driving on the battery and therefore does not have enough power to start which is why when jumped- the car will start again.

Is this correct?

I read this has something to do with the VSS- is that correct and does it make sense?

I appreciate your help and any troubleshooting tips.

I drive Jags and do all the work on them, so I have a very good working knowledge of vehicles.

I appreciate your help.

Thanks

Tom in Plano/Dallas

 

There is a Gauge fuse but no Power Window fuse.

The Gauge fuse and other fuses to the power windows also fuse other circuits.

The Gauge fuse is one fuse of many in the alternator charge circuit and among other circuits powers some engine controls.

Which exact fuses are blowing and when do they blow?

When the fuses blow, do the door locks continue to work?

 

What is called on the plastic cover to the inside fuse box is "gauge" . When out or removed once replaced- the gauges do not work and the power windows do not work. Having already read many threads on the forum- that seems common with that fuse. I understand there is no listed power window fuse and perhaps bad wording in my first post led to someone thinking I was referring to 2 when I was referring to one.There are probably other things that are not working, but my concern is why is why it blowing and the VSS makes perfect sense and does it cut off power from the alternator- again what I have read on many threads on the forum.

My question is a very simple one- does this "gauge" fuse cut the alternator from powering the car and force the car to run on the battery- that would make perfect sense under the situation that is created and I understand how, after years , the electronics of the VSS would deteriorate and cause an over amperage to the speedometer and cause a blown fuse.

There is no other fuse, to my knowledge that is blown. The fuse blows when she is simply driving down the street and eventually the car dies and has to be towed or she stops, turns it off and then it will not turn on and has to be towed until the fuse is replaced, the car is jumped and then she drives and the same cycle repeats itself.

Tom

 

Yes, a blown alt fuse will cause the alt to stop working.

Would be odd for the VSS to overload as it's signal output is extremely low.

The Gauge fuse powers the following. See comments.

ABS and traction control. Never encountered an issue

Back up light. Common for the wiring going between the trunk and trunk lid to fray and cause electrical problems.

Charging system. Suppose possible if wiring issues at the alt plug or some strange issue with the alt regulator.

Combination meter. Never encountered an issue

Cruise control. Ditto

Door lock control. Possible if the wiring frays and shorts out. Typically between the driver's door and chassis.

Electronically controlled transmission and A/T indicator. Possible if a short in the rotary switch for the A/T indicator or wiring issues at switch.

Engine control. This is large area but would be rare unless wiring issues.

Headlight (w/ daytime running light). Never encountered an issue

Key reminder and seat belt warning. Ditto

Light auto turn off. Ditto

Moon roof. Ditto

Power window. Same issues as power door lock.

Stop light and tail light Both of these systems tie into the cars tail/brake light warning system (icon on dash). The system module can fail and cause electrical issues.

 

The "alt" fuse is not blown. My question was specifically does the "gauge fuse" affect the alternator when blown. She was told that by a local mechanic as well, but he did nothing but replace the fuse and left her stranded for another time.

The woman drives the car, the fuse blows out and then she is running on the battery and runs out of battery at some point and is left stranded. The forum is full of the VSS being the cause and in looking at the replacement procedures - given age and heat (especially in the location- and in Texas heat- the electronics degrade as do the gears that go into the transmission and this would create the perfect storm for this type of problem. Could not read engine codes as someone had erased them and you cannot put the car through a drive cycle unless you want it towed back. And while I do not like guessing about parts this seems to be the most likely suspect and even though the signal may be low- if degraded it can arc up the amps.

Thanks

TBB

 

To clarify, in the previous posts "Alt" meant ALTernator, not ALT fuse.

Do have links to references stating the issue appears to be the VSS?

Yes, a blown "Gauge" fuse can the alternator not to work. This fuse is wired to the alternators voltage regulator. If it blows the regulator will not work and thus the alternator will not.

Unfortunately the Gauge fuse powers a host of other electrical items. Many of these are much more likely to cause a blown fuse then the VSS.

If you do think it is the VSS, it is easy to replace. You could do this if having some metric tools. The part is held in by one bolt. Its located on the transmission above where the two axles plug into to it.

The part is available at the dealer, auto parts stores (call first to determine if they have it in stock), online parts dealers, etc.

The VSS connects to an electrical module in the combination meter which changes the signal to something the speedo and odometer can use. Then the signal goes to the ECU. Don't think this module is available separately thus if bad would need a replacement combination meter.

If the speedo is working OK, the VSS is working OK.

Until the problem is resolved suggest the following:

Is it possible for you to teach your wife to inspect the Gauge fuse for a blown fuse condition? If so can she then change the fuse.

You could pick up a low cost "voltmeter" that plugs into the cigarette lighter. Some meters display actual voltage while others have colored LED's as in green, yellow, red.

These LED's turn on based on the cars electrical system voltage. Green indicating the alternator is working OK, yellow indicating the cars system voltage is marginal (which can also happen with a heavy electrical load at low engine RPM). Red meaning the voltage is too low and thus a problem alternator.

The next time the Gauge fuse blows, the cars system voltage will drop to that of the battery. The voltmeter will display 12.8v ish indicating (for now) a fully charged battery instead of displaying alternator voltage (typically 13.5-15.1v).

If the meter is LED meter, the yellow LED may come on then the red LED as the battery voltage drops due to the electrical load.

Your wife then seeing this could inspect and if necessary change the fuse. This done before the battery becomes too low.

 

With all due respect, first this is not my wife. Second I have all those toots and have made use of them. Third, this women is not someone that is going to nor should she carry around 20 fuses to stop and replace one that blows every time she drives.

All of the stuff you are speaking of is for someone that knows nothing of cars and does not work on them. I own 5 Jags and do ALL the work on them minus taking out a transmission or aligning the car with a string in the driveway.

The speedo could work correctly until a certain point that the VSS is chugging away with degraded electronics in its sending unit and cause an amperage beyond the 10 that the fuse is.

I have already after reading the forum taken out the fuse while the car was idling and measured the voltage from the alternator and know it is at 0.

There could be a huge number of other causes, but I am not going to speed weeks of free time doing something that intense for someone I barely know. Based on my reads and discussion with several techs at Toyota dealership, the VSS is the high suspect.

This only occurs when she is driving or just cruising down the street. Zero to do with brake lights or using the windows, seats or anything else.She is just cruising at 35 and the fuse goes and no gauges or windows and that is the symptom. The VSS could simply have broken down -perhaps under heat and vibration and as it gets used more when driving will start to draw more and more amps until the fuse goes bye-bye.

If you have any other suggestion as to why only when driving it goes out- I am happy to hear it, but none of the normal tests that I have seen you post elsewhere on the forum has any ting to do with hw this problem comes about.

Thanks, however for verifying the alternator issue.

TBB

 

The Red/Blue wire to the VSS receives power from the Gauge fuse. The others are the signal output.

Check the wiring and electrical plugs at the VSS for possible cross connections causing an intermediate high current situation.

Inspect the VSS body electrical terminal area for damage that might cause a short between the Red/Blue wire and other wires or cause an internal VSS circuit overload.

Remove instrument console and inspect wiring and circuit board for the speedometer. Red/Blue wire is Cruise fuse power. Pink and Blue wires are VSS signal. Brown is ground. Violet/White is signal source for ECU. Orange is cruise light indicator power.

Ask driver if there is any link between fuse issue and turning on cruise control.

 

Thanks- easy enough to do. She has never used the cruise control before, per her words. That is quite believable as she drives in city traffic of Dallas.

T