battery draw questions and suggestion

[kndlindsey]

I have been having problems with starting the gt-t. have to jump it and then right after a drive it won't start again.

I found soybeans "how to track down a battery drain" or something to that affect. I think it should be a sticky in this part. It was very helpful.

Per the directions I took off the positive cable and then used a test light on the post and cable and sure enough it lit up.

Pulled all the fuses, which is a bit since there is a secondary fuse box in the engine bay. Started putting them back 1 by 1 and the last fuse in the engine bay was the culprit.

Traced the 3 red wires coming off that fuse, into the drivers foot area then followed them across to behind the instrument panel. Really didn't want to pull that and drop the steering but I needed to check the speedometer and dash lights anyways.

The culprit was a red wire going to the stereo labeled "backup power". I'm assuming this probably powered the clock on the stereo?

I put it on the charger last night and will start it today and let it run then try to restart to see if that cures the problem.

Someone on here had said that despite working on cars for a long time electricity was still "magical" to them. I feel the same way. I just stink at tracing wires and even when I can trace them I don't understand enough to troubleshoot. Maybe i will get the hang of it eventually...it took me months before my brain kicked in and understood offset and backspace

I see on the diagram that the 20gray wire runs to all the lights on the instrument panel and that it runs to a "rheostat" something or other. I haven't been able to locate and identify that thingy behind the dash yet.

Since i have no lights anywhere and no power going to the 20gray wire(that I can tell, remember i suck at testing wires) can someone direct me to where the power actually comes to the lights? Or have any suggestions? I replaced and checked all the fuses.

the car has been modified. The parking light, fog light and dash light adjuster for brightness have all been taken out and replaced with a rheostat? knob like on old cars push/pull for headlights, twist to adjust brightness of dash lights.

When you turn the knob it is pretty squeaky and makes a raspy sound. But when you pull it on, all the lights come on like they should, headlights, markers, tail lights, etc. and Ron remembers twisting the knob working for dash lights so I'm assuming it's a power thing not the actual switch.

Also, on the temp guage, can someone tell me the temps that correspond to the hash marks?

It is running warm when idling or just around town, as soon as you get out on the road and get some air to it, it drops back down. It has an electric fan but Dave said it's a pusher and he would rather have a puller and might like to put the original fan back on also for added cooling.

I was out and had it running with the radiator cap off, to see if it would circulate or not. I let it run for about 15 minutes, I never saw it circulate but Cody explained that since the cap was mounted off to the side of the rad that it actually cycles through the little tube, across to the rad and you won't see it flow through like one with the cap right on top of the rad.

He had me step on the gas and let off and the water did surge up and down in the cap so he said that means the water pump was working. It ran at about the thick hash mark, the one after 1/2 and befoe the red. It has gone higher than that while driving in town but never to the red.

I nearly scalded cody as I decided i was done testing and reached in and turned off the key and when I did, it shot most of the antifreeze and water up into the air like a old faithful. Luckily he was standing back. Neither of us had any idea it would do that.

The battery issue and running hot are the only two things i need to get diagnosed to be able to go to a Dust Off car show next weekend. we need to adjust the carb hoping that will bring the boost up, it only gets to 4psi max but i'm not so worried about that part.

[ronskydivepops]

I can' t help with the electrical issues. ( I stink with electricity too!) But the temp gauge I can. Reading from left to right the 1st mark is 104, 2nd is 140, 5th is 176, 6th is 194, 7th is 212, and last one on right is 248.

[rsefczek]

i'm not the swiftest at electricity either but i'm in a very similar situation (my dash lights aren't working but everything else does). the gray wires to the lights all come off a common source (a terminal block on the back of the dash near the speedo). this common source gets the power from the rheostat (on my dash a switch, on yours, apparently, a knob) . the yellow connector has the wire that goes from the dash to the fuse box. if i ever figure out where my problem is, i'll let you know!

bob

[opelnut10]

That reostat completes a circuit and if the circuit is not as it should be then the lights will not operate or will be dim if making a interupted circuit. Clean the contacts on the back of the reostat and check it then.

[opelnut10]

The most important part to keeping your temperture down is (1) circulation (2) air movement and (3) coolant level. The electric fan in front of the radiator will aid in cooling but it also blocks some airflow going down the road. I like the fan mounted to the water pump and driven by the engine(a seven blade fan and a fan shroud). The shroud directs the air through the radiator instead of all around it and the thermostat allows the coolant to remain in the radiator longer so it can be cooled.

[Bill Hoffmann]

The culprit was a red wire going to the stereo labeled "backup power". I'm assuming this probably powered the clock on the stereo?

Correct. It holds the memory presets and powers the clock, but it shouldn't draw enough current to drain a battery overnight. A more likely cause would be an audio amp that has had its "remote" terminal tied to the main power lead, which would keep it on all the time. Do you have an external amp?

I see on the diagram that the 20gray wire runs to all the lights on the instrument panel and that it runs to a "rheostat" something or other. I haven't been able to locate and identify that thingy behind the dash yet.

That's on the row of rocker switches under the radio, to the left of the lighter. It's the one that doesn't click and has a symbol on it that looks like an instrument face. It is supposed to adjust instrument illumination.

Since i have no lights anywhere and no power going to the 20gray wire(that I can tell, remember i suck at testing wires) can someone direct me to where the power actually comes to the lights? Or have any suggestions? I replaced and checked all the fuses.

The 20 gray wires for Instrument Panel illumination are tied to a junction block (a bunch of male spade connectors), which is sourced from an 18 gauge gray wire that comes from the rheostat. The feed for the rheostat is an 18 gauge gray/green wire that goes through the yellow I. P. connector to the first fuse position. That fuse has two sources, the headlight relay and the parking light rocker switch. If your headlights have been rewired with a standard push-pull switch, chances are the dash light feed was eliminated in the process. All this stuff is in the wiring diagrams, by the way.

the car has been modified. no doubt

The parking light, fog light and dash light adjuster for brightness have all been taken out and replaced with a rheostat? knob like on old cars push/pull for headlights, twist to adjust brightness of dash lights. When you turn the knob it is pretty squeaky and makes a raspy sound. But when you pull it on, all the lights come on like they should, headlights, markers, tail lights, etc. and Ron remembers twisting the knob working for dash lights so I'm assuming it's a power thing not the actual switch.


Since the replacement push-pull switch has a built-in rheostat (the raspy thing), there is a tap for dash lights on it (it would probably be a physically small terminal on the switch). You can check if it works with your test light. If it's dead, you could tie a new feed to another switched terminal (use you test light to find out which terminals go hot when the switch is on). The dash lights would come on but have no brightness control. From here, I would run the new feed the same way as the original if possible, i.e. through the original fuse. Just copy the circuit from the wiring diagram. You may find most of the original wiring in place. My GT had a push-pull setup when I bought it. First step for low beams, second step for high beams! When I rewired my headlights I was able to return to the stock setup because the relays and old wiring was all still there. Good luck.

Bill

[kndlindsey]

okay, my head is still swimming with all the electrical and i will probably be plopping that one is dave's lap, lol! ah, it's good to have a significan other that can do electrical

on the cooling and starting. I went out today and jump started it, the mercury light on the pole where i plugged the charger in had tripped the breaker. I got it to start and let it idle for about 15 minutes. At about 8 minutes in it was around 194, then i saw the guage drop back down to 176 so I'm assuming that was the thermostat opening, but then after running it longer it went back up and settled at 212 where it seems to want to run.

Dave wants the original fan and shroud back on, in addittion to the electric fan so i will be doing that today. Barney will be donating some parts

On a good note, after running it and shutting it off, it started every time. I will go out later and see if it still starts.

Dave still thinks there is probably a charging problem but when I did the battery drain test that wire is the one that was draining so I am going to hope that was it.

When you turn it on and have it running the amp guage runs at about +10, it did settle to around zero once but when i was watching it was at +10 and when i turned on the headlights it dropped to -10. I have done some reading on this but don't remember enough to know if that is normal or a problem and what problem?

Thanks guys, Kim

[Bill Hoffmann]

When you turn it on and have it running the amp guage runs at about +10, it did settle to around zero once but when i was watching it was at +10 and when i turned on the headlights it dropped to -10. I have done some reading on this but don't remember enough to know if that is normal or a problem and what problem?

The ammeter should hover around zero with the engine running and things working as they should. A 10 amp positive reading on the ammeter indicates the battery is severely discharged, and the alternator is charging it. Any negative reading means the alternator isn't keeping up with the load, and you are discharging the battery to run the car. There is another possibility that can confuse the issue. Since you have had some "rewiring" already, it could be that some new feeds have been taken from the battery or starter post. That will cause the ammeter to read incorrectly. Any new feeds should be taken from the alternator B+ terminal so that the ammeter can read the current drawn by the new device.

[kndlindsey]

I know there is one feed coming directly off the positve battery cable, i believe it runs the electric fan, not sure though, haven't looked at things long enough to memorize them. Darn, i was so hoping that i didn't have to do the alternator.

Dave and Ed think I should just take in the alternator off Barney, and have it checked and then amped(pun intended) up to 65 amps. As long as the price works out okay. We have a guy locally that does this sort of work and is very good.

[Bill Hoffmann]

I know there is one feed coming directly off the positve battery cable, i believe it runs the electric fan, not sure though, haven't looked at things long enough to memorize them. Darn, i was so hoping that i didn't have to do the alternator.

You may not need to. Instead of the battery cable, just take the feed for the fan from the big stud on the alternator. Not to bring up old topics, but it should start with a fuse or 6" fusible link (preferably) directly connected to the alternator stud, then spliced to your fan supply wire.

Dave and Ed think I should just take in the alternator off Barney, and have it checked and then amped(pun intended) up to 65 amps. As long as the price works out okay. We have a guy locally that does this sort of work and is very good.


That could help if your problem is too much drain from you cooling fan and other accessories that your present alternator can't keep up with, but if you have a constant drain it will stress your battery with frequent discharge-charge cycles. You still need to find out what's causing the drain.

You never answered the stereo amp question. Is there one? I have an old radio, not even digital, no clock, that would drain my battery in a couple of days if it was connected to a constant (unswitched) supply, even if turned off.

A more useful tool for figuring this out is a multimeter with a 10 Amp DC range. You have to be careful, because if you exceed 10 Amps you may damage the meter (usually there's fuse protection inside, though). An ammeter is always inserted in series into the circuit. To figure out where the drain is, make sure the ignition and all accessories off. Then remove fuses one at a time and touch the meter probes to the fuse terminals. The meter will measure the actual amount of current flowing in that circuit.

[baz]

kim have you tried swopping to a known good battery and having yours checked ,it could just be dead

[SpringGT]

About the heating problem, try taking the electric fan off and put the stock seven (?) bladed fan and radiator shroud back on. That is all I have on my air-conditioned '73 GT and the engine temp runs right in the middle of the gauge, even in Houston and New Orleans summers. Losing the electric fan may also help with the charging problems.

[kndlindsey]

Bill, lots of good info from you and I am absorbing it. I still forgot to look and see what the piggybacked wire to the positive post is running but will tell dave and we will try hooking it to the alternator instead. beats taking out the alternator as this car has power steering added and it that sits right on top of the alternator.

As far as an amp, like an add on to go with the stereo? Don't think so, just a cassette player/radio in the dash and then 2 speakers in the back, little ones.

I thought i had it licked but after running the car tonight for about 15 minutes when i shut it off it wouldn't start again. Course I didn't have the battery cables on tight, hadn't retightened them from doing my testing. Dave thinks it's that, I think there still isn't enough alternator to keep up with the elec. fuel pump and elec. fan that have been added.

Dave swears I'm an alien but when i was changing out the batteries(answer to next question, yes baz, i put the battery i just bought new for the other yellow opel and the one I took out was from Mar. of 2004 but I think i will get them both tested) If i put my arm on the air cleaner, it's up front, mounted in the nose area above the battery, and then put my wrench on the positve cable to disconnect it, I get little pops in my forearm. Like a little pinch. I thought maybe the polished aluminum housing was just scraping my arm, but I rubbed it up and down, and then layed my arm on it like i had before, then touched the wrench to the cable and PINCH again. Haven't gotten Dave or Cody to test it out yet, i think they just like thinking i'm nuts.

SpringGT, that is what i spent the better part of today doing. No way to get the shroud on, the turbo bits and pieces crowd the area by the radiator cap too much to get it in there. For some reason the crank pulley(remember i'm a novice) was a double pulley on this car. I had to take the rad out, then take off the pretty chrome pulley on the water pump area, then pull the fan from Barney, it was a 7 blade that had been trimmed down but it was too thick.

some lines from the power steering are running along the bottom side of the rad area and it tilts it in towards the engine more than normal so you can't fit as much in between the engine and rad. So I had to go look at my other yellow opel, it had a much thinner fan, but blades were too long.

Had to take off the double pulley and swap it for a single from other car, trim the fan blades down and grind some off a bolt on a little pulley for the power steering i believe. God I'm beginning to hate the power steering.

Had to take off the electric fan because we had to use an impact wrench to take off the double pulley and it wouldn't fit. Finally got the whole shebang back together and went to start it and the electric fuel pump wasn't coming on. Traced the wire and we were a little puzzled as it seems to run up and over to the carb. Anyways i got in to turn the key on so Dave could test for power and lo and behold the fuel pump was running again.

We fired it up(no jumping needed) and let it run. It was at 212 in short order but Dave was adding back antifreeze and water as we of course lost most of it during the work. Once he got the water back in it dropped down to 176 and the slowly up to 194. The electric fan wasn't coming on so I revved it up some and then it kicked in. With an electric fan and a five blade shortened fan it runs right at 194.

With the turbo adding a lot of heat to the engine compartment does that seem okay? Of course that was just idling and for about 20 minutes or so. So I don't know, we will see.

out of curisoity. My power steering stuff says Toyoda on it?