THANKS GUYS! Your prompt responses are all greatly appreciated. I think I will just go and purchase a new relay, rather than soldering the old one, however just having the option of soldering the old one is cool too. These cars are just simply incredible! I am looking forward to reaching 400,000 miles and beyond, thanks again!


Best Regards

HAPPY NEW YEAR!

Doubt you harmed anything. It sounds like the overdrive relay is failing amd the fix is to buy a new one.

Or you can resolder it too but I'm solder-handicapped so I avoid doing that unless it's an immediate problem.
--
Chris Herbst, in Wisconsin.

You didn't hurt anything. It's no different than stomping on the accelerator or manually turning it off to pass someone. Even at 75 mph. You can go almost 90 in 3rd. What's probably going on is the same problem we've had in our 88, which is that the socket for the OD relay is making intermittent contact. I've been too lazy to pull the whole fusebox out to tighten up the connections (or push the wires back in - they're probably pulled out a bit.) Ours doesn't go into OD sometimes when it's hot- a wiggle of the relay (it's the tall one in the forward right corner of the fusebox) makes it connect and everything's OK until the car is turned off. Our dash light acts up too when this happens, and wiggling the relay fixes that too. Kind of annoying but I've been unmotivated lately..... just drove it to Virginia and back and simply left the ashtray out to get in there. I'll fix it soon, honey, honest.
--
Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE, 91 244: 808K total

First, I am not a transmission expert, but from what you said and my personal experience with the AW70 series I doubt you damaged anything.

The AW70 is a 3-speed transmission with an electronic overdrive that servs the same function as a 4th gear. The button on your shifter disables the overdrive, just like shifting from 5th to 4th in a manual 5-speed. The arrow on your dash illuminates when overdrive is disabled. At speeds below, say, 45mph, it effectively does nothing because the car's speed is too low for it to attempt to use overdrive. At highway speeds, your engine speed will increase about 1000rpm when you disable overdrive, because you're effectively shifting down to a lower gear.

The overdrive is turned on and off by a system consisting on the button on the shifter, a relay behind the ashtray, and a solenoid on the transmission. Probably 80% of the time, overdrive problems are caused by the soldered contacts on the relay developing hairline cracks which make it short out. To fix this problem, either reflow the contacts with a soldering gun or get a new relay (around $35). The FAQ has detailed information on this and just about every other 700/900 related issue.

jeff daigle
'89 745GL 137,000mi