Why no check engine light? 88 5.0

[lib88stang]

Can someone tell me why my 88 5.0 has no check engine light? My car has been acting up and I'm tired of just changing parts. I want to know exactly whats wrong with it.

Can you put a check engine light out of a stang that has one?

 

[trbkrb]

I guess it is still speed density? Ford only put check engine lights in the mass air cars. But you can cehck for codes by using a test light and a jumper wire and following these instructions:

http://www.dalidesign.com/hbook/eectest.html

I use it all the time on my 87.

If it has been changed to mass air, you can put in the check engine light bulb in the cluster, but I'm not sure if you have to do anything else to make it work correctly.

Good luck!

 

[silver87]

My 87 which is speed density has a check engine light, and it just came on, so time to check the codes

 

[lib88stang]

Is there a scan tool to read codes off of my 88??? Why does an 87 have a light and not my 88???

Ford sniffed too much paint in 88

 

[lib88stang]

What do I have to do to have check engine light?

What is involed in making my car have a check engine light??

 

[jrichker]

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

Save time and your sanity on a pre 89 car and buy a scanner or use the test ligt/voltmeter method.

 

[trbkrb]

There was a long thread several months ago on this exact subject. The cars with factory check engine lights in 87 & 88 were the California emissions cars, probably because California required it. Ford didn't make the light operable in the 49 state cars until they put mass air across the board in 89. If a non California 87 or 88 car has a light, it has most likely been changed to mass air and had the light installed. The code reader is the easiest way to get the codes, but I'm too cheap to spend the money on something I can get for free with a test light.

Even if you have the light in your car, you still need the code reader or have to jump the wires under the hood to get the codes, the dash light just takes the place of the test light or meter in reading the codes. And it lets you know there is a code in memory. But you have to have the mass air computer to operate the light. The speed density computers are not set up for turning on the check engine light. I just try to check for codes every so often to see if there are any regestering, like maybe at each oil change or so.

 

[tjm73]

It's a common misconception that the check engine light tells you exactly what wrong. It tells you something is out of spec and points to the general area where the problem is, but doesn't tell you exactly what's wrong. You still have to diagnoss the problem.

 

[603mustangs]

There was a long thread several months ago on this exact subject. The cars with factory check engine lights in 87 & 88 were the California emissions cars, probably because California required it. Ford didn't make the light operable in the 49 state cars until they put mass air across the board in 89. If a non California 87 or 88 car has a light, it has most likely been changed to mass air and had the light installed. The code reader is the easiest way to get the codes, but I'm too cheap to spend the money on something I can get for free with a test light.

Even if you have the light in your car, you still need the code reader or have to jump the wires under the hood to get the codes, the dash light just takes the place of the test light or meter in reading the codes. And it lets you know there is a code in memory. But you have to have the mass air computer to operate the light. The speed density computers are not set up for turning on the check engine light. I just try to check for codes every so often to see if there are any regestering, like maybe at each oil change or so.

maybe this is why mine doesn't work. EEC is 87/88, engine is a 90. Waiving the white flag.

 

[Moosee1955]

Speed density systems have check engine lights, and the diagnostic plug for scan tool is up front passenger side. Every mustang from 83 on with an o2 sensor has a computer and check engine light. Are you sure you don't just have a burnt out or missing bulb for your cel? You can buy a fairly cheap scanner for the EEC 4. I have one I'd like to sell cheap as I have a 2000 ford expy with obd2 system. Send me a pm if interested or to my email [email protected].


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[603mustangs]

Speed density systems have check engine lights, and the diagnostic plug for scan tool is up front passenger side. Every mustang from 83 on with an o2 sensor has a computer and check engine light. Are you sure you don't just have a burnt out or missing bulb for your cel? You can buy a fairly cheap scanner for the EEC 4. I have one I'd like to sell cheap as I have a 2000 ford expy with obd2 system. Send me a pm if interested or to my email [email protected].


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I did check the bulb and buy a scan tool a a couple weeks ago. This car a mix of three different years, a lot of the wires are spliced or connectors dangling.

 

[Moosee1955]

Well theirs your problem, you've got a Frankenstine car pieced together. You may have to rewire everything to get all your sensors and computer talking to each other. Other than that you could try circumventing around it all, but come smog time your going to be s.o.l.!


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[603mustangs]

Well theirs your problem, you've got a Frankenstine car pieced together. You may have to rewire everything to get all your sensors and computer talking to each other. Other than that you could try circumventing around it all, but come smog time your going to be s.o.l.!


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Finally! Found the problem, or another problem. I had continuity through everything to the cluster and the light bulb worked. Followed the circuit board looking plastic sheet on back of instrument cluster and found this (see pic) the broken circuit on right is connected to almost all the bulbs, mostly idiot lights. They make copper tape to fix this?

 

[Mustang5L5]

86-88 speed density 5.0 mustangs do not have a functioning check engine light. The bulb is there, but it's not wired in. The 2.3L cars DID have a functioning CEL those years.

First 5.0 to get a working cel was the 88 Cali cars with mass air. Mass air swapped 87-88 cars won't have the CEL automatically work. You still need to add another wire first

The diagnostic test port is rear drivers side of the engine bay, next to the brake booster.

And yes, this is a 12 year old thread


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[Mustang5L5]

Finally! Found the problem, or another problem. I had continuity through everything to the cluster and the light bulb worked. Followed the circuit board looking plastic sheet on back of instrument cluster and found this (see pic) the broken circuit on right is connected to almost all the bulbs, mostly idiot lights. They make copper tape to fix this?

Is just jump a wire under the grounding tabs of the bulb sockets

Also, that appears to be an 87-89 Guage cluster.

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[603mustangs]

86-88 speed density 5.0 mustangs do not have a functioning check engine light. The bulb is there, but it's not wired in. The 2.3L cars DID have a functioning CEL those years.

First 5.0 to get a working cel was the 88 Cali cars with mass air. Mass air swapped 87-88 cars won't have the CEL automatically work. You still need to add another wire first

The diagnostic test port is rear drivers side of the engine bay, next to the brake booster.

And yes, this is a 12 year old thread


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Where do I add a wire from and to? Not the jumper wire on cluster, for the cal

 

[603mustangs]

Is just jump a wire under the grounding tabs of the bulb sockets

Also, that appears to be an 87-89 Guage cluster.

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[Mustang5L5]

That should do the trick.


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[Mustang5L5]

Where do I add a wire from and to? Not the jumper wire on cluster, for the cal

You need mass air first. Your still running and SD harness and computer.

Honestly, it's not really worth it. Of the possible 90 codes, only 13 trip the cel. It's not like modern cars.

Buy and innova 3145 for $25 and just run the codes every now and then.


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[603mustangs]

You need mass air first. Your still running and SD harness and computer.

Honestly, it's not really worth it. Of the possible 90 codes, only 13 trip the cel. It's not like modern cars.

Buy and innova 3145 for $25 and just run the codes every now and then.


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Then I'm done. The light works now with the jumper even though I bought the scan tool. Thought it worked like a new car with all the sensors. Thanks to everyone for the help.