My slow down lights do not illuminate at start-up. It is a 1993 348 speciale series. Do these lights only light up when needed? I was under the impression that they illuminate at start up like all other warning lights and then turn off after 30 seconds or so.
They should indeed come on briefly during start up. Have they ever worked? It's possible that someone has removed the bulbs. Easy to check, just two screws hold the dash pod in place. Do you have a stock exhaust system, or do you have an aftermarket system with no thermocouples at the outlet end of the catalytic converters?
Thanks Miltonian....and do I feel silly, I just went outside to check something else (the auxilliary light) and when I turned the key I DID notice the Slow Down Lights come on for about half second and then turn off, while the rest of the lights stayed on. I presume I did not notice them in the past because they come on and off so quickly and the rest of the lights stay on, and I have never stared at the dash while firing it up (I will from now on), I look down at the dash after the car is on and by then the slowdown lights are off. However, to answer your questions anyways, I have an Ansa exhaust system. I have never heard of this before buying the car, I had only heard of Tubi. Since I am not mechanically inclined, I have no clue what thermocouples are so I took 2 pictures and hopefully you can tell me what the thermocouples are - if I was to guess I would say they are the plugs coming out of the cat in the second picture - the first picture is from the top of the engine, the second picture is from underneath looking up at the engine. thanks again. Image Unavailable, Please Login Image Unavailable, Please Login
Yes, that's the OXY sensor in the first picture, and the exhaust temperature thermocouple in the second picture. I don't think you have a problem there, Ace! If the thermocouple reads an abnormally high temperature in the catalytic converter, it will send a signal to the exhaust temperature ECU (up on the shock tower), which will send a signal to the Motronic ECU (behind the seat), which will cause the "slow down" light to come on.
Thanks a million Miltonian, you were a great help here. I am slowly but surley learning the engine components and terminology. . Have a safe and happy Memorial weekend!!
As a side note, you might want to ground your O2 sensors. Take a short piece of similar wire size as what you see connecting the sensor to its plug, use green or brown if you can. Take a stainless steel hose clamp fit around the barrel of the sensor and clamp 1 end of the wire to the sensor. Ground the other end to a nut you see at the end of the cam cover, where other grounds are attached. If it's like my car, the 2 nuts are different sizes, right and left. This is really easy and a brainless step to avoid faults you might otherwise get erroneously.
Hey Vince, Bee Jay here just lurking. Do you have a picture of this done? I've been getting momentary check engine lights, and I may need to ground my O2 sensors. Bee Jay
Thanks BeeJay and Vince - I was going to ask the same question about whether you have a pic of this. I believe I have it pictured in my mind based on your excellent descripton but you never know....
Thanks for the info guys. I have a similar problem. One of the slow down lights stays on. Every now and then it switches off, but after a while it comes back on again. Could this also be a ground problem? Ton
Here is a quick picture for your use. I probably will tin the ends of the ground wire at some point but for the time being this is what it looks like. Image Unavailable, Please Login
Just something to think about; I had the same problem slow down / check engine warning light, I also had a little rattle sound. At first I thought it was the bypass valve but after checking further I noticed it is coming from the left side by the catalytic converter. When car was cold I stock my hand down touching the Oxygen sensor and it was completely loose. I tighten it, started the car and no more rattle or warning lights.
I have my car apart for some light restoration work and figured I'd replace any bulbs in the dash while I had it out. I knew the 1/4 slow down would light briefly during the startup procedure, but not 5/8. So I put another bulb in, cleaned the connection, and nothing. I even took the bulb out from the oil indicator directly below it because I could see it was working, and then moved it to the slow down 5/8 position. Turned the key again and slow down 1/4 lights, but 5/8 still does not. I'm a little worried someone might have messed with the light in some other manner to make it go away. Is anyone aware of another reason why this indicator wouldn't work when it is not the bulb? Thanks, Tom (1990 348ts)
