Electrical gremlins

[JohnH55]

I had an unusual issue with my 2001 Explorer sport today. I got in the truck and started it from cold, I waited a minute for it to idle down then took off. I hit a small bump and the radio shut off, then on then off, then on till the next bump. My abs light also started flashing, and didn't stop. My speedo was sitting about 5 mph higher than it should have. I then go into a parking lot turned the truck off, then turned it back on. No lights and everything was back to normal, I hit a big bump at 20 mph, and it did absolutely nothing. I've had this issue with the abs light coming on and giving me a harness mismatch code, but the speed and radio are new. What is the problem here? It's been awhile since I fixed anything on the truck, does it just want more attention?

 

[J_C]

Intermittent faults are difficult to troubleshoot. I'd start with unplugging, inspecting and replugging the two bulk wire connectors under the hood.

2nd gen issues? Try this first!

Sometimes a gremlin can be caused by the smallest thing. There are 2 large wire bundle connectors on the firewall. Both are held tight with a 10mm bolt. Any bad connection in either plug can cause just about any issue. from bad transmission shifting, bad o2 sensor readings, no start, no...

www.explorerforum.com

Considering the speedo and the ABS are related to getting a good signal from the rear diff speed sensor, I'd look into that if either of those faults happens again, but it happening due to a bump suggests to me a chaffed wire shorting or maybe corroded fuse box contacts, so removing and replugging the related fuses might help.

Of course it wants more attention! It's getting older, age related issues start to pop up. Nickel and dime you they claim, but at least if you DIY it isn't cost prohibitive to continue ownership.

 

[JohnH55]

Intermittent faults are difficult to troubleshoot. I'd start with unplugging, inspecting and replugging the two bulk wire connectors under the hood.

2nd gen issues? Try this first!

Sometimes a gremlin can be caused by the smallest thing. There are 2 large wire bundle connectors on the firewall. Both are held tight with a 10mm bolt. Any bad connection in either plug can cause just about any issue. from bad transmission shifting, bad o2 sensor readings, no start, no...

www.explorerforum.com

Considering the speedo and the ABS are related to getting a good signal from the rear diff speed sensor, I'd look into that if either of those faults happens again, but it happening due to a bump suggests to me a chaffed wire shorting or maybe corroded fuse box contacts, so removing and replugging the related fuses might help.

Of course it wants more attention! It's getting older, age related issues start to pop up. Nickel and dime you they claim, but at least if you DIY it isn't cost prohibitive to continue ownership.

I did recently have the engine engine harness out, and I didn't spot any bad wires on it. Would it be fine using dielectric grease in those two bulk head connectors? I'll look at the diff sensor, and start unplugging and replugging fuses

 

[J_C]

^ Yes a "little" dielectric grease can help but mostly it's useful where the connectors join, the perimeter. If one of the contacts itself is getting corroded, I would unplug and replug it a few times before any dielectric grease on the contacts so the friction helps to clean the contacts. You might also be able to remove the block in the connector that holds the contacts in for individually cleaning them - not sure, haven't looked that closely at those two but many of Ford's connectors are like this, able to be opened to extract contacts.