midnightride42

87 N/a automatic

ok i have posted before that my fues keep poping every now and then and to the point where it is melted. sence then it has not happened but,

ok had the starter go out replace it along with bigger and better battery. sence then,

ok i posted this too, my car is stuck in overdrive , i can hit the button but nothing happenes. shifts fine but wont go to redline at WOT. so know it stuck in overdrive.

also in the last few day i can turn the car on and the exhaust temp guage lights up but the neddle is stuck then all of a sutton will move or wont till the car is turned of and back on. then this morning i went ot start the car and both my exhaust temp guae and a/f guege didnt light up and windshield wiper didnt work. i turned the car off took key out and put it back in and turned key and then there you go both guages worked and so did the windshield wipers.

any idea on what could be going on here.

my logicon has been out for a while but im going to take a dayu and see if i cant work out all the electrical problems.

could it be the battery or the guages using to much power? i have them hooded up using the cig fuse holder and the i believe sun roof fuse holder. so they are always on and lid up when car is on.

it s kind of scarry not having windshield wipers. etc. please let me know if anyone has ny input.

i am assuming its prob. just a little thing that needs some attention. well that is i hope.


plus whos the one to talk to about the logicon? going to search for write ups but incase i run into trouble would like to write someone instead of posting in here.

thanks again
andy

alwayssideways

sounds a little like me .. i can have my radio on and stuff. but when i open the door. my radio shuts off, and all my liights go out.. i think for me it a door switch and a loose fuse in my fuse box. but if you have the gauges hook up to your ignition they shouldnt just shut off unless you have a bad ground . or bad connection . but if your wipers are doing the same thing.. i would clean all the grounds you can find . the fcs are known for haveing bad electronics. normally caused by bad grounds.

WAYNE88N/A

42, you're confusing me with all of your problems, lol...

First thing that popped in my head is a bad ignition switch...Try "jiggling" it while on to see if your wipers and/or gauges come back on...

If this isn't it, you've got some wiring problems, but you need to take them one step (or component) at a time- start with the wipers (which just might be the switch), and go from there...

midnightride42

well the wipers have worked fine till now except the first turn, the go up then get stuck but this morning like i said i turned the car on and the aftermarket gauges didnt come on eve nthe air fuel ratio guage and neither did the windshield wipers. driving lights came on tought and so did the normal guages in the car. first time that has happened.

where all the grounds located or let me refrace that is there a photo of all the ground i should be cleaning/ replacing in our car in the haynes manuel?
let me know please


ill try the hole ignition thing.

man one problem after another i tell ya.
thanks a lot for all the replies so far.

SureShot

With that many symtoms, I'd look upstream for a common cause.

The body is grounded to the engine by a short primary wire that bolts to the topmost part of the bell housing, and clips on to a cheesy spade connector on the firewall, just to the right of center (passenger side) above the brake & fuel lines.
That wire carries ALL accessory & ECU load.
If that wire is the least bit weak, your electrons will get creative & try to find another path in the harness grounds.
Then all kinds of bizarre things can happen.
An original exhaust system will have some ground straps, but who has an original exhaust?

midnightride42

are you saying it could be the exhaust? didnt know the exhaust had a ground. i will look into twhat you just left me. thanks again
im going to get a voltmeter and see what i come up with

thanks again.

WAYNE88N/A

No, the exhaust wire is just a bonding jumper- not a ground wire. It was designed that way to prevent static electrical buildups under the car (probably from the airflow) from discharging and creating sparks back there, where you would least want sparks

Remember, ground wires carry current for components to use, bonding jumpers just maintain a "similar electrical" potential between the metal parts of a machine. Aircraft have billions (it seems) of bonding jumpers, none of which are actual circuit ground wires (helps during the lightning strikes)...

SureShot- you're forgetting about the main engine-to-chassis ground wire...The one at the starter...It can also carry all of the loads related to the ECU, if the housing-to-housing contacts are nice & clean...

kabooski

My car has MAJOR electrical problems right now
pain in the ***

My headlight retractor fuse keeps blowing
I think I fried my Microtech computer wont power on
My electric fan is on a Relay which had one "hot" one "cold" ground and power feed
well now the "cold" is "hot" I.e always on when it only came on when I turned the key

Im going to have to re-do my whole electrical system and run everything of independent relays and switches....grrrr

I took the harness off the frame to have the engine bay painted leaving all the plugs and connections intact just pushed to the side...
after I intstalled the motor.......I added 6! braided ground straps (5 engine to chassis and 1 tranny to chassis ) for a total of like 10 grounds with the stock ones


VERY frustrating trying to find the problems

WAYNE88N/A

Well, the retractor fuse should be easy enough- it's a very simple circuit, only feeds the two retractor motors. I'd look at the area of the harness that gets bent every time the lights go up & down, for starters...And disconnect one of the motors at a time, to see if the short is in the main feed, or a branch to one of them...

What the heck is a "hot" and a "cold" ground???

I'd start by removing all of your fanciful bonding straps (which WILL act as current-carrying grounds), and go back to the original intent and design of the OEM wiring...

Some of you guys just don't understand circuit theory, lol...

kabooski

your right I guess not lol

I'll try those tips
Thanks

Relay ---->

87=Headlight, fuel pump etc(feed)
86=power from ignition switch("cold") only on when switched on
30= positive battery post ("hot") always on
85=ground

SO what grounds should I add if any? and where

WAYNE88N/A

Ahh, now I see why you're calling them hot and cold...

Depending on how you want to look at things, grounds are always hot, because there are no switches between the component & ground in a normal simple circuit, and there are between the power wire and the component. Therefore the ground wiring always has the potential for current to flow...

If you want to presume that a voltage potential has to exist on a wire (compared to 0 potential, or a ground) to classify it as "hot", then the above won't hold true...

Or there's the "big picture", visualizing the entire circuit at once, and realizing that it's "hot" only to the switch, whether it be a toggle switch, or a transistor "switch" inside the ECU, or a temp switch, and the rest of the circuit is "cold", including the power wire "downstream" of the switch, plus the component, plus the ground...

Or vice-versa, if you subscribe to the quantum theory of electrical flow- the "hot" side will be the grounds, the components, and all wiring up to the switch...

I'm rambling again...

kabooski

Hey one last question Wayne

Iis there a ground cable that attaches to the starter?

WAYNE88N/A

Since your starter uses the most current, by far, than any other component on the car, YES, and the closer the ground connection to the starter body, the better...

In the OEM wiring set up, the negative cable from the battery runs through a grounding clip that's bolted to the left front strut tower for the main chassis ground (it's hidden by tape, you can't see it directly), then directly to the starter upper bolt...

This cable also provides the main current path for the alternator's ground circuit, which is why Mazda bolted it to the rear housing side of the starter upper bolt (educated conjecture), instead of on the starter side (although, since it's easier, some of us, including me, bolt it up directly on top of the starter body, under the upper bolt nut- as long as your metal-to-metal contact between the starter, tranny, and rear housing is clean & tight, you won't be dropping too much voltage with this routing)

SureShot

Maybe your harness is different than mine. My S5 only had one wire at the starter mount (before I relocated the battery).
My battery ground post used to connect directly to the starter mount, which grounded the engine, but not the body.

You're right about the exhaust bonding grounds. Their primary purpose is/was corrosion control, but they also help with engine to body grounding.

The engine harness has some light weight grounds from eyelets on the engine to an eyelet at the ECU mount.
They are what tries to carry the load if the primary #10 wire from the bell housing to the firewall fails.

The above may be S5 specific.

WAYNE88N/A

Ahh, but what is within 4 feet of that starter ground? That main chassis ground, on the strut tower. All electrical flow from the chassis returns to the battry from that point. In other words, the starter ground, and the entire chassis ground, are on the same exact circuit. So, in the OEM scheme of things, all grounds eventually flow to that point on the strut tower. And don't forget about the main source of current flow through the engine housings- the alternator. That tranny-to-firewall jumper is actually a minor player in the scheme of things. Kind of hard to envision, but think about it for a while & it'll come to you. In fact the only ground I've added to my OEM layout has been to remove that jumper, and run one from the firewall directly to the rear rotor housing ground. That way the injector circuit (and some sensors) doesn't have to flow through the rear rotor housing-to-rear housing-to-tranny contact surfaces to find its ground. I've also been tossing around the idea of jumping (bonding) the alt to the starter ground, down near the starter, so it doesn't have to flow through the housings. As much hylomar as I used during the rebuild between the housings, I'm surprised it still has a path anyway, lol...

WAYNE88N/A

Just read your "edited" version, lol...

So you're saying the S5 negative battery harness doesn't ground at the left strut tower? You can't see it unless you pull all the tape & crap out of the way...

SureShot

My (+) cable has a "Y" to the fuse block, but the (-) cable is just a single #6 wire.

Hmm - all this time my car has been missing a "Y" in the battery ground cable?

WAYNE88N/A

It's not a "Y", its a clip that crimps onto the negative battery cable run as it passes the strut tower. The insulation is stripped off of the cable, and the crimp is at the bare wiring exposed....Like I said, it's not visible, Mazda wrapped it up real well (which is a good thing)...

Now you've got something to do, lol...Kind of like "where's Waldo"