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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
when i drive my car going about 40 to 65MPH
with nothing on, (AC/Heater/Radio etc)
runs fine.. BUT!!!!!
when i turn on my heater or ac(dont matter) and turn that fan speed to MAX
and im driving it my tacometer goes crazy and the car acts as if its going to die
and jerks BUT the second i turned it off goes back to normal driving.
when i drive my car going about 40 to 65MPH
with nothing on, (AC/Heater/Radio etc)
runs fine.. BUT!!!!!
when i turn on my heater or ac(dont matter) and turn that fan speed to MAX
and im driving it my tacometer goes crazy and the car acts as if its going to die
and jerks BUT the second i turned it off goes back to normal driving.
HELP? im lost
Boy I waited YEARS to answer this question!!
My 88 GTA did that exact same thing years ago. Driving down the highway at 70 mph, hit the fan switch, felt like I dropped a cylinder, tach,volts, Oil Pressure gauges went crazy. Turn it off, all is fine.GM worked on it for a week and NEVER cured it.
What it was, was a bad ground for the heater motor. Run a separate ground wire from the heater motor ground to the ground strap on the firewall. Seems crazy, but it cured the problem.
My 88 GTA did that exact same thing years ago. Driving down the highway at 70 mph, hit the fan switch, felt like I dropped a cylinder, tach,volts, Oil Pressure gauges went crazy. Turn it off, all is fine.GM worked on it for a week and NEVER cured it.
What it was, was a bad ground for the heater motor. Run a separate ground wire from the heater motor ground to the ground strap on the firewall. Seems crazy, but it cured the problem.
are you saying to cut the ground wire n half, then ground the wire from plug to firewall or just open up the middle of the black wire and add a wire to it and ground it?...
Just add a wire, attach it to the blower motor ground
tryed that..did change anything..
tryed the fire wall ground and then drove it still acts same
tryed the neg side of battery just for sake of mind..same thing acts odd
Grounding remains a possibility though. Check very carefully and make sure the braided ground strap that connects the engine to the firewall, at the rear of the pass side head, is connected.
In fact you could just add another ground wire from engine to chassis somewhere convenient; such as, from the point where your negative battery cable is bolted to the block, to a nearby substantial body bolt or something similar. You can get a cable at a parts store that looks like a batt cable but has eye terminals at both ends that will work perfect for that.
Grounding remains a possibility though. Check very carefully and make sure the braided ground strap that connects the engine to the firewall, at the rear of the pass side head, is connected.
In fact you could just add another ground wire from engine to chassis somewhere convenient; such as, from the point where your negative battery cable is bolted to the block, to a nearby substantial body bolt or something similar. You can get a cable at a parts store that looks like a batt cable but has eye terminals at both ends that will work perfect for that.
well the reason i have thought about changing the switch
there is a part on the control panel that i replaced due to a burn n melted mark on it..i went to the junk yard found a good piece replaced it and i no longer needed to smack the side of my dash to get the fan switch to work or come on sorta speak.
i did check the ground strap it is infact installed
every time i get out of the car tho i get shocked if i touch the car or anything metal after that.lol
i will add another ground to the chassis from the battery tomorrow n see what happens.. what a pain in the ***
i noticed the 4 wires coming from the relay to plug type connector was melted
i cut the wires off n spliced them together. iv yet to drive it to test it ill post back after the test drive...
The other area you need to look at it the High Speed Fan connector on the firewall right above the pass rear valve cover. That POS connector is bad news also!
The other area you need to look at it the High Speed Fan connector on the firewall right above the pass rear valve cover. That POS connector is bad news also!
that dont exsist there at all, all i see is the ground strap
This is that connector I was mentioning that is notorious for shorting out; it controls the High Speed Fan circuit.
The other "red" wire that you are looking for is that ground wire that I added. I mentioned I should have picked a BLACK piece of wire, but all I had at the time was red.
The issue you are having is definitely something in the fan circuit. Due to the fact that it starts acting up when you turn the AC/Heater Fan on.
This is that connector I was mentioning that is notorious for shorting out; it controls the High Speed Fan circuit.
The other "red" wire that you are looking for is that ground wire that I added. I mentioned I should have picked a BLACK piece of wire, but all I had at the time was red.
The issue you are having is definitely something in the fan circuit. Due to the fact that it starts acting up when you turn the AC/Heater Fan on.
ya that picture is showing that connection near the heater hoses in the firewall
i see nothing like that. ill look again tonight an move that plastic shielding away n see if its just wrapped up
the engine was rebuilt so maybe moved down or left a bit
That's because it's not in the tubing. It's hanging out there, right out in the open.
But it doesn't matter. That's not "the" problem at hand, even though it's probably "a" problem, and is wasted to ashes, like everybody else's.
Did you add a ground cable from the engine block to the firewall or other convenient chassis point?
Theres a ground strap from fire to engine block
and theres a ground from battery to fender
is it still necessary to add another ground ?
i have looked all around under the hood and i do not see that kind of connector at all.
just so yanno im not mechanically dumb i know my way around a car
so dont want ya to think "omg this guy is retarded lol" i just do not see that at all.
im been listing n looking hard for this..
can you suggest the possible locations on a 92 RS 25th anniversary edition for this red wire connection
also a question.?
when i bought the car it ran fine.no issues..
only thing iv done since i got the car was change spark plugs and spark plug wires. i have taken off the air filter cover completetly off a few times..checking for busted air lines n just looking at my stuff there.
could it be possible the coil is losing power when i have the fan on?
i know it sounds silly but..it only starts acting like its trouble shifting/advancing and tachometer is going crazy..but if i slide the ac to OFF
it all stops.and drives fine..
That connection doesn't matter. Don't worry about it.
Your problem is caused at a place where BOTH the blower motor power and the fuel pump, coil, etc. power pass through the same point. The one in question handles only the blower motor and therefore it is physically impossible for it to cause the symptom at hand.
However, just to answer the question, the connector in question is above the pass side valve cover, just below the windshield cowl. If you start at the purple wire from the blower motor and follow it, you will come to a plug with 5 wires in it, plugged into a small box; that's the blower motor high-speed relay. One of the other wires in that plug will be a big fat red one. Follow that wire toward the driver's side and you will come to the connector you're asking about. Assuming of course, that some PO hasn't hacked on the wiring some kind of way; a possibility that can never be completely discounted. And in fact, if the wiring has been altered, it's entirely possible that it was done in such a way as to make possible (or even unavoidable) what would have been impossible with the factory wiring. Needless to say, there's no way any of us out here could guess what kind of a hack job might have happened, so if that's the case, you're kinda on your own. You'll just have to examine every single wire and connection until you find the hack. None of us out here is going to know where that is or be able to see it for you.
That connection doesn't matter. Don't worry about it.
Your problem is caused at a place where BOTH the blower motor power and the fuel pump, coil, etc. power pass through the same point. The one in question handles only the blower motor and therefore it is physically impossible for it to cause the symptom at hand.
However, just to answer the question, the connector in question is above the pass side valve cover, just below the windshield cowl. If you start at the purple wire from the blower motor and follow it, you will come to a plug with 5 wires in it, plugged into a small box; that's the blower motor high-speed relay. One of the other wires in that plug will be a big fat red one. Follow that wire toward the driver's side and you will come to the connector you're asking about. Assuming of course, that some PO hasn't hacked on the wiring some kind of way; a possibility that can never be completely discounted. And in fact, if the wiring has been altered, it's entirely possible that it was done in such a way as to make possible (or even unavoidable) what would have been impossible with the factory wiring. Needless to say, there's no way any of us out here could guess what kind of a hack job might have happened, so if that's the case, you're kinda on your own. You'll just have to examine every single wire and connection until you find the hack. None of us out here is going to know where that is or be able to see it for you.
ok ill do that..that has helped alot ill trace the wire as mentiioned and see what i come across with that red wire being a HOT 12v lead makes total since because of it being connected to other sources. i have not replace the relay yet..its 10$ at part store i might just do it to rule it out even if didnt make a change..peice of mind.
ill check the voltage with a meter when i get home i read that need to check the red wire and orange wire too..
i apreciate all the help it just really drving me crazy since it just started happening out of the blue lol
i might just for a temp solution is connect the heater blower motor to a toggle switch just so i CAN use the ac...110* weather in phoenix and no ac is umm hot..lol
i was still stumbling, then i decided to install a ground strap and change the ground location for my 12inch sub amp ground wire..soon as i did that, my Volt meter went back up, all my gauges too came back to life as if it wasnt reading right..
moral of story ..i bet money hands down i didnt ground the amp correctly to much paint around the ground location..(/face palm)
05-27-2015, 02:01 AM
