Electrical Problem - Will not allow overdrive when outside temp. is above 80 degrees

[BSeyler]

I'm posting this for my son - it's a 91. 5 auto. transmission CTD. When the weather is cold, the transmission works fine. When the outside temperature is around 80 or above, he gets intermittent shifting to and from overdrive at highway speed. When this happens, the wait to start light flashes quickly and continuously. It may clear up fairly quickly and act normally, or may last for several miles. I'm not sure where to go with this. Any help will be appreciated.



Thanks!

Bud

 

[cerberusiam]

Start by checking battery cables for tightness and corrosion. Pay particulare attention to the base of the clamps and any sign of corroson inside th ecable sheathing. Check the body grounds also to make sure they are making contact. Load test the battery to make sure it is holding a charge and not warming up then shorting. The WTS light flashing is seeing some sort of power interuption, ground problem, or issue that is setting it off.

 

[JLEONARD]

I would do a TPS adjustment. That always solved an auto shifting issue for me.

 

[BSeyler]

Thanks for the replies. I haven't had a chance to look at it lately because it's his daily driver. Earlier in the year, we put a new battery in. The old one was 6 years old and we figured that was a good place to start. We have cleaned grounds, but I'm thinking it wouldn't hurt to replace the cables, as they appear to be original. We will check all of the grounds again, too. I found this pickup for him two years ago, but he's only been driving it for a year. It spent the first year in the machine shed while he was deployed. About all I did during that time was start it and drive it once a month. As with any aged vehicle, it has had a few issues.

He called me this morning and said he thinks it's over charging, so I'll check that out tonight. He said the gauge was reading high and the battery stunk. Guess it's time to run it into the shop this weekend.

Bud

 

[cerberusiam]

He called me this morning and said he thinks it's over charging, so I'll check that out tonight. He said the gauge was reading high and the battery stunk. Guess it's time to run it into the shop this weekend.

Same thing happened to my 92, the charge wire and positive battery cable had corrosion inside the sheath and was over charging. Started burning out headlights and dash bulbs constantly.

 

[BSeyler]

Thanks, I think it's time to replace some old cables. Luckily, this was a one owner vehicle and I have gotten to know the man who owned it previously. He always had it serviced at same dealership where it was bought and he has records for everything, so that takes some guessing out of the equation. (My son's previous pickup had been owned by several before and was a crap shoot when he bought it - unfortunately, turned out to be more crap than good. ) The dealership is a small family owned business and they are friends of my wife's family. It was Ford and Chrysler until they had Chrysler taken away. Sad day - the owner told me there was nothing that compared to a CTD. Anyway, since the pickup is 28 miles away, I may just haul it to my house and go from there.

Bud

 

[cerberusiam]

I would start with the positive battery cable and check all the fusible links. With a charge problem you can burn them partially thru to the point where the vibration wll start them disconnecting at random times. As the system heats up they will start dropping connections also and drive you nuts trying to find the problem.

 

[HHhuntitall]

Also, I'd like to add that those northern trucks seem to develope an issue on the ground wire at the block at times. I've had several in here to work on that have that green corrosion and powder growing in the block end of the cable. Occasionally, I see problems in the positive wire connector from the alternator to the battery, that lies just short of the battery in the 6ga wire. Water seems to be drawn to those for some reason.....

 

[BSeyler]

Things got busy around here and we haven't had a chance to do much on the pickup. It's parked in the machine shed until things slow down. I ordered an oem positive battery cable. The negative is not available, but we can build one. Hopefully, we can get it in the shop this weekend and get something done. Thanks for the replies and we will report back. Hopefully, with good news.

Bud