STOP:The answers to the questions are located in the comments. Also, if you do not see the information you seek in the first post, be sure to use the "Archive Categories" list in the left column or the search bar above. If you still need help, feel free to Ask Sparky

Sparky,


I have a 1997 Ford F-150 4x2. It has a electrical problem I can not find. The small relay in the fuse box clicks (I think it is the second from the top), the dome light flashes along with the clicking relay, also when you hit the brake the dome light comes on real dim and the door chime beeps each time you hit the brake, it is as if you opened the door, regardless of the door being open or shut. And the power windows do not work. I am not real good at tracking down wiring problems, but I did a Google search and everything I found pointed towards the gem module. So I bought a used one from a salvage yard and installed it. It still does the exact same thing. How much would you charge to help me find my problem? I already blew $150.00 on a gem that didn't work. I would like to get this truck going again. 




Hi David,


Initially my though twas a weak body ground but it could also be a blown/missing fuse with a circuit back feeding (requires removing and looking at the fuse element to check it). Check your owners manual for fuse locations. You also could have weak body power supply.  There also could be wire damage at the brake pedal itself. Just a few things to check. Does the truck run?

I do not have a set fee for helping. I prefer for you to donate, as a percentage of the repair savings. Much like you would  tip a waiter, a percentage of the restaurant bill. 




Yes, the truck runs. was working fine, my sister borrowed it, brought it back and I got in it about 30 minutes later and it was a mess, I swore she must have done something, lol but couldnt think of anything she could of done. It had a aftermarket alarm in it, it was going off all lights were flashing, horn honking ect.. along with the other problems. I tore the dash apart and disconnected the aftermarket alarm, and that left me with what I described earlier. I am going to go to the shop now and check all of the grounds and power wires, along with the fuses. 


I checked the power and grounds under the hood, fixed a couple that looked bad below the ebrake. Checked the ground in the loom to the door. We have all data but I dont know how to read the schematics. 



Hi David,

Do you have a scan tool that will communicate with the GEM?  Have you checked the grounds behind the right and left kick panels? Is there any sign of a water leak around the fuse box or GEM? Although you replaced the GEM, there could be corrosion inside the fuse box. Let me know what kind of scan tool, voltmeter, test lights or other diagnostic tools that you may have access to.



We have a Tech 2, a Genisus, and a older snap on scan tools, and volt meter, test light, ect. I checked the grounds on the left kick panel, replaced the ends on a couple of them that looked bad. I didnt know there were grounds on the right kick panel. I will check there tomorrow if I get a chance. I work in a auto repair shop. But I do mainly mechanical work, engine and frame. My boss is good with electrical stuff but he is always to busy.



Hello, you were right, I found a rusty ground behind the passenger side kick panel. Thanks so much. Its great to have my truck back.


Hi David,

I am glad your truck is fixed.







Hi Sparky,


I ordered a blower resistor and harness combo and two weeks after replacing it, the high blower does not work again. What could be the problem? All other speeds work.


Since all other speeds work we know that the ground is okay. What you need to do is switch the key on, set the blower speed to high (#5) and check for power on the red and orange wires at the blower resistor seven wire connector. Let me know what you find.

Sparky


Well Sparky,

I did what you suggested and found that the red wire was burnt. It started working as soon as I touched it. I guess I should have went ahead and changed the connector when I changed the resistor. I bought both at the same time but the connector looked okay.


Lesson learned. It is very difficult to predict if a connector will fail or not with this system. I agree with GM that the connector and the resistor should be replaced at the same time, regardless of how good it looks!!!!


Sparky



Sparky

I read your write-up on replacing a GEM module in a 1997 Ford. Thanks!

I have a 97 Expedition, the dealer told me after 10 minutes and $300 that I need a new GEM and the price tag was going to be $1700.

The symptom is this: everything remains on after the key is turned off and removed. Drains the battery. Does that sound like the GEM or are their other things that would cause this? Thanks


Dan



Dan,

I guess they just don't want to work on a 1997 Expedition. About $450 to $700 would be in the normal range for a GEM replacement on your truck, depending on the cost of the actual GEM for your truck. Some are higher than others depending on year and trim levels. Now on to your problem. You stated that everything stays on with the key off. Can you be more specific, windows, lights, dash warning lights, radio,engine, interior lights, wipers and etc? If the windows and radio stay operational but the dash warning lights are out, I would suspect one of the relays on the left side of the interior fuse box. Specifically relay #2 (battery saver relay) and relay #5 (accessory delay relay). Try tapping on the relays or removing them. If you remove them, look for signs of water intrusion. These trucks have known problems with leaking windshields that damage relays and GEM's. If the dash warning lights stay on along with other items I would suspect a faulty ignition switch or ignition switch linkage.

Sparky,

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Sparky

That was it, relay #2. Works like a champ, and change back from my $20. Much better than $1700.

Thank you so much!

Dan



Hi Dan,

Glad I could help. As we all know nothing is truly free, so I need some help from you. The site is intended to generate ad revenue to keep it free. Please encourage as many people as possible to use the site or if it is easier you can make a Thank You Sparky donation at the following link.

http://store.the-electric-connection.com/Category163


Sparky,

Hi Sparky,


I have a 2001 impala the radio lights and the (P.R.N.D.2.1) lights work in the daytime and at night I cant see them, Also the cluster lights dont seem to work at all, Can you give some tips please.

Arthur


Hi Arthur,

It would seem like either the panel dimming fuse is blown or the dimmer circuit board in the headlight switch is faulty. Have you checked to see if the switch is turned down to the full dim position?

Sparky


It's the first thing you do when something is not working is to see if it is turned on. It is fixed I went to work on it as soon as I read your reply, it was the dimmer circuit board.
Arthur







Sparky,
This past weekend I received the replacement Blower Motor Resistor for my '05 Chevy Silverado, installed it and now the blower is working fine.  However now the driver's side will only blow hot air (being in 100 degree texas heat I'm not sure if the heater was on or if it was just outside air) it will not blow cool air at all. The passenger's side seems to be working fine.
My assumption is not that the part is bad or that I installed it incorrectly, I would just like some tips on what I should do next.

Thanks for everything

Mike

Hi Mike,

First you need to try a recalibration procedure. Set the controls to high blower and temp to medium. Make sure the key is off. Disconnect the negative battery terminal for at least one minute. Reconnect the cable, start the engine and DO NOT adjust the controls. After about 4 minutes turn the key off for at least thirty seconds and then restart the engine, check the controls for function. If problem is gone calibration worked if it is still there you will more than likely have to replace the driver's side blend air door actuator, pretty easy. Let us know if you need more help.

Sparky


Sparky
 
The recalibration procedure worked like a charm. Thanks for your help, 
the next time I have a problem with my truck I know who i'm gonna ask first.
 
You're the best!

-Mike

I have a 2002 trailblazer Wednesday I had the battery replaced, since then I notice that whenever the a/c is cut on it dies out



Hi Sam,

It sounds like carbon build up on the throttle plate. If you can stand to drive it long enough the computer should learn around the condition just like it did over the life of the vehicle so far. If you want to clear it up sooner you should clean the throttle plate. Most shops keep the cleaner and will clean it for a fee or you can purchase throttle plate cleaner at most parts stores. If you clean it yourself you should wear some sort of protective gloves as you need to spray the clean on a rag and then wipe the throttle plate clean. Some disassembly is needed. If you have Throttle Actuator Controller (no throttle cable between throttle body and gas pedal) Be sure not to spray the throttle bore as it can damage the motor bearings and seals. Do you have a service engine soon light on?Sparky
No just changed the battery because I had to jump it off a few times and took battery in for evaluation it was still on under warranty so they just prorated the price of new one. Then this started happening. So just spraying this down will clear it up and car will not die with Air Conditioner on.

Hi Sam,
Yes, Cleaning the throttle body should correct the condition. You should be more sure that it will after you inspect and find some carbon built up on the throttle plate and throttle bore. However I do caution you about "spraying it down" , Apply the cleaner to a rag and wipe it clean. Excessive amounts of the solvents can damage seals, bearings, sensors and idle control motors!!!! Make sure you only use approved throttle plate cleaner. Other cleaners can damage interior coatings. Sometimes you have to wrap a rag around the end of a screwdriver or similar device and basically make a large Q-tip in order to clean it due to depth.
Sparky

Hi,
The heater / AC blower motor works erratically. It will not run on any speed except High most of the time.
However, even at "5" (Hi speed setting), it will not start immediately most of the time. If you set it to 5,
it may take 5 seconds or longer to begin running. Even after it is running it will not run at 4 or any lower
speed. Sometimes it did begin to run at a lower speed if you just left it there...it may start several minutes
later but was not predictable at all.
I am an electronics tech so have tried troubleshooting this situation. Initially, I assumed it was going to be
the "resistor" block since it at least always worked at high speed but got to where it never works on the
lower speeds. Then I got to thinking about this failure to start immediately on the high speed. I thought
if the motor "bearings" are getting bad, they may be resisting the startup on the lower speeds to where
it won't run except on high speed (with full voltage).
So I temporarily connected a new blower motor but it behaved the same way... runs after several seconds
of waiting, on high speed only. It doesn't run on any lower setting. I then checked for 12 volts at the connector
with the motor disconnected. It shows about 11.5VDC on the high setting and just a few tenths lower on each
lower setting. (I'm assuming with no load it is not showing the actual voltage drop on those lower settings
that would be normal with the motor connected).
So we know it isn't the motor and also not the resistors since it doesn't explain why the motor still takes
several seconds to start when on High as this should be applying the full battery voltage instantly. With
reading some amount of DC even through the resistors, they should not be an issue nor the series
hi temp fuse.
I noticed a relay "click" each time the blower switch is turned on so assumed it's contacts may be pitted
and responsible for part of the problem. After locating the "box" containing the relay, I noted there were
two other relays on the PC board which also contained 2-3 integrated circuit "chips" . The board had two
multiwire connector blocks which were the connectors for the cabling from/to this assembly.
I'm not familiar with this assembly. I have a "generic" diagram of the blower, switch, and relay but it doesn't show
any other circuitry involved. I'm wondering about the other components on this circuit board and if they are
involved in the function of the blower and it's turning on. I also noted that when the blower switch is turned
on to a low number, you hear the relay click on, but when up to the high setting, it clicks back to off???
Manually closing the relay contact seemed to have no effect on the motor.
So... after all this discussion, what are your thoughts on what is going on here and is this circuit board the
source of all the problem here? Is the circuit board repairable at a component level by myself? If I could get
the part numbers off the IC's, I may be able to change them as there are no other "active" parts on the board
and appears to be nothing overheated/burned.
The numbers found on the "box" with the relays were:
10097889 and 7156J These don't appear to be the GM part numbers and there were no other numbers found
except an insignificant one on the board itself.
Thanks for your support,
Harlan

Hi Harlan,
The first thing to check when the inop condition is power to the three fuses in the right hand fuse box. HVAC Control / 20 amp, HVAC Hi / 30 amp, DIC/HVAC 10 amp. The HVAC Hi fuse should be hot at all times and the other two should be hot with the key on. If all are okay the next step would be to check power and ground at the blower motor itself with all of the harness connectors in place. Let me know what you find and I will provide more info as you test.
Sparky



Hi Sparky,
Thanks so much for your tips. I have a wiring diagram of the circuit in question. After much troubleshooting, I did find the
supply voltage to the blower motor switch was very low to none! It at times would measure around 5 volts. Further checking
at the HVAC control fuse found the same condition at the SUPPLY side of the fuse.
I temporarily bridged that fuse to the adjacent fuse's supply (heavy gauge wire) and everything worked perfectly... all the
speeds of the blower switch functioned as they should. Oddly, with the fuse removed, the voltage on the supply side
would read normal but as soon as the fuse was in and the blower switch on, it dropped to nearly zero.
So the problem now is why and where is the 12 volt supply to this fuse losing it's voltage. There are two lighter gauge
pink wires on the back of that fuse block which carry the supply voltage. I have not been able to locate where they
originate due to the cumbersome wire bundle they run into. Apparently this circuit goes through the ignition switch but
then where does it eventually connect to the battery positive? With the small gauge wire being used (maybe 18-20 gauge..
which seems rather light for running a motor that consumes a fair amount of current) it wouldn't seem likely that much
arcing (corroding / oxidizing) would take place resulting in this condition in the switch.
Also you would think messing with the ignition key and switch position would have an intermittent result where
it would at times work at least to some extent.
If you can find the wiring diagram of how this fuse is supplied and where the supply wires physically run, that would be the
next step and a great help. At least then I could check the voltage at the input to the ignition switch to hopefully rule it out.
BTW... is the ignition "switch" removable from the key function itself... so the electrical switch could be replaced without
requiring a new "key / lock" assembly?
Thanks very much for your time and wading through this mess... been quite a struggle... aching back and sore neck from
crawling around under the dash, etc. :-)
Harlan
Good Morning Harlan,
As you stated in your first email, this has been an ongoing erratic condition that has gotten worse. The ignition switch is your problem as mentioned earlier. To check go to the ignition switch connector at the base of the column. It should make up the center part of a larger junction connection. Check both large red wires for 12 volt supply. If 12 volts is not present check the ignition fuses under the hood. If it is present and it most likely it will be then proceed to check the orange wire for 12 volts with the key on. It will not be there. Next jump the orange wire to one of the red wires and see if the blower now works properly.
The electrical part of the ignition switch can be changed without having to deal with the lock cylinder and key issues. It is fairly simple to change so don't be intimidated by it. You will probably have to invest in some torx bit drivers and sockets in order to replace it if you do not already own them. Any repair manual should show procedure but if you need help just drop me a line.
Sparky,


Hey, Thanks for the speedy reply... sure do appreciate it!
Well suppose it may be the ignition switch then if you're confident
there is nothing else in the "line" that would possibly limit the
voltage the way this behaves.
I don't have the car here now to look into it so will see what happens
when I try the steps you suggested.
Thanks again.. will try to let you know the results.
Harlan

Good Morning Harlan,
As you stated in your first email, this has been an ongoing erratic condition that has gotten worse. The ignition switch is your problem as mentioned earlier. To check go to the ignition switch connector at the base of the column. It should make up the center part of a larger junction connection. Check both large red wires for 12 volt supply. If 12 volts is not present check the ignition fuses under the hood. If it is present and it most likely it will be then proceed to check the orange wire for 12 volts with the key on. It will not be there. Next jump the orange wire to one of the red wires and see if the blower now works properly.
The electrical part of the ignition switch can be changed without having to deal with the lock cylinder and key issues. It is fairly simple to change so don't be intimidated by it. You will probably have to invest in some torx bit drivers and sockets in order to replace it if you do not already own them. Any repair manual should show procedure but if you need help just drop me a line.
Sparky,



Hello again,
After further troubleshooting, I did conclude as you suggested, the ignition switch is the entire
problem. I've never had this part of a car apart before so it was a bit challenging to get at the
switch area on the steering column. Managed to have something close to the necessary tools
to do the job but sure was a lot of work.
Another thing that made it more difficult was that the wiring harness to the connector block under
the dash needed to be reworked. I had tapped into about 5 wires some time ago when installing
a remote car starter. So I had to get that all out on the bench and splice those lines back into
the new wiring harness. Yes the switch is apparently only available with it's attached wiring
harness with black plastic connector block.
Well this has been a difficult one since I was hoping it would only be the blower motor at the
beginning but was really the ignition switch... can't wait to tear it apart and see what contacts
look like to cause this trouble. Also left in the new blower motor as it occasionally would squeal.
Thanks very much, Sparky and have a great day!
Harlan



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