1990 Dodge Grand Caravan possible ground issue


#1

My van has the V6 engine, and I don’t know much about the history because I bought it as a cheap second car when the transmission went out on my good car, but I did check it out before buying and it runs well otherwise and seems pretty decently maintained. It’s got a little over 53,000 miles. Maybe half the time I commute to work, after driving on the freeway for awhile (no set distance, although it seems to be after about 30 miles or so, today it was maybe 20) my van will start to jerk, feels similar to when you’re driving fast and quickly tap the clutch on a manual, and the windshield wipers will turn on just once, and the check engine light comes on. If you ignore the jerking, it starts becoming more frequent and violent, and is only resolved by pulling over and turning off the engine, then restarting and continuing on my way. The check engine light stays off after restarting, until whatever causing the issue happens again. Sometimes it doesn’t happen for the rest of the commute, sometimes it happens every 5-10 miles, and it’s always freeway driving, never in town, although, sometimes in town, you tap the brakes and the windshield wipers go just once. Googling turned up a case of a guy who says the same thing happened to him and he had to replace his ground straps to fix the issue. Between 2 years of auto shop in high school, Google and Youtube, and a Chilton’s manual, I can pretty much fix anything that doesn’t require tearing down the whole engine, but I cannot find anything in all those resources that will tell me where the ground straps are to change them out. Can anyone help me out with that?

Also, what other things could cause this nonsense, if it isn’t the ground straps? It’s annoying, and I already leave over 2 hours early for work to drive 80 miles on the 4 busiest highways in California; this isn’t making it any easier to get to work on time.


#2

The ground runs from the battery to the engine, balck wire. There are straps running from the engine to the chassis. Make sure the battery connections are clean. What you need to do is have it scanned while the light is on. The make blue tooth scanners that plug in and send the code to your phone. Autozone or advance will scan it free.


#3

How is he going to get it scanned when it only happens after 20 - 30 minutes of driving and the check engine light goes out as soon as he restarts it.
The wipers moving a little bit sure sounds like a ground issue.


#4

I presume that @Knfenimore; was suggesting that he buy the scanner mentioned and using that to get the codes.

I agree that it sounds like a ground issue. Sometimes people do repairs and forget to reattach the ground from the engine to the firewall. Then by the time they realize it, they don’t want to remove anything to reattach it. They presume that it won’t make a difference.

Yosemite


#5

If you cannot find the existing ground wires, you can always add an extra one. Attach a wire on any metal part of the engine block and attach the other end to a metal part of the body. The Chrysler cars I am familiar with have ground wire running from the block to the firewall. Look behind the engine and you might find it there.


#6

And now I know what I’m doing on Saturday. Thanks for the tips, guys.


#7

yeah, my ground strap is shaped like a shoelace and is made of braided copper, it is screwed to the firewall behind the engine, but yours could be different. I believe its called chassis ground in my manual


#8

I think all chassis grounds are of the braided wire, but I have not worked on every car out there.

The OP should look around on the firewall and the engine on that side and look for a braided, uninsulated strap.

Yosemite


#9

I would start by inspecting and if necessary replacing your battery terminals, cables, ground straps, and the engine to body ground cable, if there is one. While your vehicle is low mileage, it is a quarter century old and no doubt corrosion has accumulated. Also, sometimes low mileage vehicles have been owned by people that don’t drive much, and so assume that no maintenance is required because “I hardly drive it.”


#10

If replacing the ground straps doesn’t fix it, the next suspect could be in the wiring, on my dad’s 88 Grand Voyager we had a wiring harness that ran under the battery (why i don’t know) that was being eaten by battery acid, but that would only let the van run for a few seconds before dying in our case. We chased more than our fair share of gremlins with that van and relegated it to occasional use before just selling it to the scrapyard a few months ago.


#11

OK, so, since I last posted, I replaced the very corroded ground strap from the block to the firewall, cleaned both terminals and checked out the entire length of the negative cable with no corrosion to be found, checked out the wiring harness under the battery and that looks good (it was wrapped to death in this really awful cloth tape that I had a hell of a time getting off so I could inspect things), and…things have since gotten worse. It ran like a dream for a whole day after the ground strap was changed, now every time my girlfriend drives it, she says it dies. The windshield wipers come on just once occasionally, not always when hitting the brake now, but when she presses the brake, she says the rpms drop and it just dies. Whatever is causing that new fun issue is happening more frequently now also, it died 4 times this morning on her 10 minute drive to work. Ideas?