I own a 1979 Trans All all stock with Olds 403 motor. Twice this has happened to me... Back in January 2014, started car from cold, let it warm up, then press brake pedal to put in drive and car instanly dies. No power anywhere except headlights. Was told to change fusible links down by the starter which I did and car ran again. Incedently, the fusible links had already been changed by previous owner(s) so likely not a new problem. What was interesting is that I disected the old links and neither looked fried.
Issue did not happen again until this past weekend. Exact same scenario. So I know to change out the links to get it running again.
Anyone have any leads as to where the short is originating? Again, this happens when I press the brake pedal to put it in drive after a cold start and short warm up period. Very randon, has happened twice in last 9 months. Anyone had this happen to them?
I think I'd investigate up under the dash to see if there is something shorting out by the movement of the brake pedal before I'd go chasing gremlins in the circuits.
You may want to also make sure the battery ground is good to the block and the battery. A bad ground can change the path that current flows and could be pulling extra current through the fuse link that normally would not be there.
I agree with techinspector, check to see if the brake pedal assembly is pinching or slicing through any wire connections. Also, check for a loose connection on the brake switch which should be located at the top of the brake pedal assembly. See if it is properly attached, or maybe it has come apart and when the circuit opens, causes a direct short to the fused system. Follow the leads back from this brake switch pod, see if they might be connecting to some other sort of relay that may have been installed to act as a kill switch for the car. You did not say if the car was automatic or manual. If automatic see if the 'neutral safety switch connection on the column connector is loose or frayed. If this is an automatic, the next time it fails, drop the car into neutral and see if it will start then. If so, it's your your floor shifter transmission indicator pod gone bad, tells the system it's in drive when it's still in park, but when you move shifter to neutral, it clears the check point and allows car to start. techinspector, what do you think of this possibility?
Hey thanks for the replies! I really do appreciate them. Love my Trans Am but this problem has it just parked in my garage.
The car is an automatic TH350. There is no alarm on it. The only change made is the previous owner installed an electronic fuel pump back by the gas tank and the power for it was tapped somewhere in the engine bay.
Also, I have peeked under the dash where the brake pedal assembly is located and could not find anything touch a wire. Many times after the January incident I tried to recreate the probem but no luck so I thought I magically went away until it happened again last weekend.
Finally had a free day so I tinkered with the T/A... When this happend the first time back in January, I replaced the two fusible links and all turned out well. Car had power again and it started. Afterwards, I cut open the two links that I had just removed and noticed neither was fried or had blown which I thought was odd.
So yesterday I experimented by jacking up the car, removing the bolt on the starter, then placing the bolt back on the starter and tightened it, lowered the car, and voila - power is back and the car started!
I did not change the links, just went through the motions as if I had.
Could I have a bad positive cable? Bad connections? Or maybe a need a new starter? Should I still search for a short? I'm stumped. Lol!
If you don't have a ground cable between the block and frame, I'd install one as I believe that you have a ground problem. Ground the engine to the firewall and the block since they were probably left off when the engine was installed.
There is a ground strap on the rear of the passenger side head to the firewall. But I noticed the negative battery cable does not have the ground that usually goes to the fender. I am going to get all new cables and clean up all connections.
Dumb question - by simply removing the bolt on the starter where the positive battery cable attaches, then reattaching it, what exactly is happening that revives power to the car for me to fire it up again?
If there is any grease or oil on the bolt you are reestablishing contact by taking it off and putting it back on. Also if you do not have a lock washer on the bolt I would suggest that you install one as your connection could possibly be loosening up in which case you're not getting the full voltage to the solenoid.
I see. Thanks! Trying to learn how these things work.
Although the bolt was on snug, there is no lock washer. I will install one when I get the new cables. The bolt wasn't too greasy but there is definitely some gunk all around that area on the motor.
Do not over tighten, the bolt is copper/brass and it strips easily. A regular lock washer will work, but in that application I prefer outside star lock washer.
Thought I would share an update of this situation. Up to this weekend, I still had no power when turning the key. Decided to check the wiring. I began at the wire terminal/block on the firewall and almost immediately found something. The main red wire up near the brake booster had been poorly spliced and crimped . The crimped connector was burnt and the wires had poor/no contact. I pushed in the wire to make better contact, went into the car and turned the key and what do you know, the motor cranked. I followed the red wire and only to find a second crimped section! Bought some 10Ga wire and replaced the section of wire but I soldered the connections and covered them with heat shrink. Car is back running! Yay. I hope this was the problem. Some pics: First crappy crimp job: Close up:
I like crimping, but I like using bare connectors, and an indent type crimper, like a Stakon tool. I slip heat shrink tube over the wire first, and then shrink it over the connector after the crimp. Bare can also be soldered after the crimp, and that makes a very solid connection.
Yes that 10ga wire is pretty thick. Althouh my soldering skills aren't the best, I was able to get a nice connections where the crimps had been. I gave the wires a good tug and they did not budge.
Thanks for the crimping tips. I will look into the Stakon tool.
Not sure why those crimps were there in the first place. I suppose old repairs to the wire. I could see that the red insulation on that wire as it headed down towards the main block on the firewall is not in the best of shape so I wrapped it with electrical tape for now. My goal is to replace that entire red wire all the way down near the starter where then it brances off. The booster and hood are in the way so that will be a future project.
Thanks again for the help! It was nice taking it out for drives Saturday and Sunday.
This is the Stakon crimper I use. It's for non insulated connectors, but I use it on insulated also, and just put heat shrink over the connectors either way.
When soldering large gauge wire, 10 and above, after the wire is stripped I apply flux to the exposed wire. If not there I will drill a hole in the connector being used to allow solder to flow. Then I will clamp the wire in a vise or a helping hands fixture, you can find one at HF, place the terminal on the wire and and heat until the flux starts to flow. You can use a heavy duty soldering iron or a small torch, Bernz-O-Matic or pencil, to apply heat and feed solder through the hole in the terminal until it flows the entire length of the connection. I forgot to say that heat shrink should be added down the length of the wire before putting the terminal on.
When you trace that wire down , make sure there is a fuse /fusible link protecting that wire . that wire is likely the main power supply to the fuse box & as such is always hot , possible that the short splice wire you replaced was originally a fusible link that went bad... hate to see you burn the car down..
dave
that red wire could also be the power supply to the heater fan , either way , be sure it's protected...
When you trace that wire down , make sure there is a fuse /fusible link protecting that wire . that wire is likely the main power supply to the fuse box & as such is always hot , possible that the short splice wire you replaced was originally a fusible link that went bad... hate to see you burn the car down..
dave
that red wire could also be the power supply to the heater fan , either way , be sure it's protected...
Thanks for that Dave. I didn't even think that it may have been a fusilble link at one time.
The red wire coming off the fuse box goes down to the area around the starter where it branches off in three directions. One goes to the starter solenoid where there is a fusible link (I know because I already replaced it). But not sure about any other fusible links down the road where those other two red wires end up (alternator maybe?).
If you want you can replace those fusible links with circuit breakers. I have all my hot wire feeds running thru a 70 amp resettable circuit breaker, with the exception of the battery cable that runs to the starter. Works great and is very handy when working on the electrical system..... I manually trip the CB and all the circuits are dead, when I store it for the winter....... no more disconnecting the battery etc...... The main feeds are protected by the CB and the individual circuits are protected by the fuse block.
Here she is. Pretty much all original. Just wish didn't have the electrical bugs.
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