[updated:LAST EDITED ON 28-Mar-02 AT 12:54 PM (EST)]I'm sure there are various forms of the problem I am encountering w/ my '84 Bronco, but I'll try for an answer anyway...

I seem to have some electrical problems. I don't know if they are all related to one another, or what. I know sometimes wiring harnesses can go bad and such, so just seeing what you all are experiencing. Here's the list:

1. My tach jumps around erratically when I'm at idle, in Park and in Drive. It seems to happen more when the headlights are on. It also pegs out high when the tranny is in Reverse.

2. The driver's side window motor doesn't always operate.

3. When the headlights are on, I can see they are flickering slightly.

Any help is appreciated.

Thanks...

 

Could very well be a short or two, but I'd start by making sure every thing was properly grounded. In particular, be sure that the (-) cable on the battery is making good contact with BOTH the frame and the engine block.

Ford attempted to answer this by removing some insulation off of the negative cable halfway down, and tying this into the frame via a clamp, and then continuing onto the block from there.

When I upgraded my cables to "0" gauge, I decided to run the negative cable directly to the frame, while running another short "0" cable (with bolt-thru terminals on either end) from the frame attachment point to the engine block (on the passenger's side). For good measure, I also ran another grounding cable from the engine to the frame on the driver's side, and ran ground straps from the body to the frame on both sides.

There are a lot of electrical accessories taking their respective grounds from the engine or body to make a path back to the battery. If any of these have a problem making that path back, you get some strange things happening. Good luck!

 

>
>When I upgraded my cables to "0" gauge...


Thanks, Mr. Restorit. That's a great idea. So, you used 0-guage wire for ALL those connections? What style lugs did you crimp on each end, the heavy duty kind or the little cheapie kind? I should probably undo all the existing ground straps anyway and clean them w/ a wire brush, too, huh.

Thanks.

 

Does this all happen with the engine running? If so it might be the voltage regulator some fords have an internal regulator on the alternator so you might need to have a shop check it out. Hope this helps. Rick Jaeger

 

Yes, Rick, all this happens when the engine is running. Great idea on the voltage regulator. After I check all my grounding straps, I'll go that route.

Thanks a ton!

 

I should have used better lugs (NAPA will make up custom cables or, at least ours will), but I bought mine pre-made. I used "0" gauge from the battery positive terminal to the starter solenoid, and then from the solenoid to the starter, and bought the appropriate length with the appropriate terminal types. From the negative battery terminal, I used "0" gauge to the frame, and again from the frame to the engine block. I used a heavy screw through a 1" outside diameter fender washer, which then passes through the two terminal ends and down into the frame (actually, if memory serves, it's the crossmember). I bought mine from a farm supply store that had a good selection of lengths and heavy gauges. While the ends were pre-made onto the cables, they have held up well (although I may have gotten slightly better contact had the terminal holes been smaller). I've been happy with them in the past several years since the upgrade. I run a 1000 CCA battery with the cables, and have forgotten to plug in the block heater and have still had the truck crank (though slower) and start at -40F with no problems, at all.

 

Start with the grounds first. You can get a good book on electrical and vacuum trouble shooting from Helm Inc. (www.helminc.com).

Make sure where the ground cables are attached that it is very clean. After fastening the grounds, coat them with some sort of terminal coating, available at all auto parts stores.

 

I have an 86 302 EFI that I totally rebuilt except for the alt seemed to work good at the time. I put all new cables and ground straps. The problem I am having is when I am going down the road all my gauges will spike to the high side gas, charging, oil, and temp. Thia stumped me for the longest time until I finally checked the alt and found it had an internal regulator and that a diode or something was falty and causing an occassional surge that was spiking my gauges. I don't have power accessories or a tach so I don't know if they would have been affected. I ask if the engine was on when you had these problems because you can use the windows and lights with the engine off. It sounded a little like my problems with the tach bouncing around. Rick Jaeger

 

sounds like an altenator problem i had the same problem with the lights

 

One of the MOST notorious problems with the 80-86 Ford Electrical system (as well as other years) is the voltage regulator. Remove it from the fenderwall. Sand the paint off where the screws go into the fender, sand the back of the voltage regulator, re-attach with new larger diameter screws. The dam ground to the voltage regulator is the MOST overlooked spot. I have repaired dozens (well okay at least 15 or so ) Ford electical gremlins this way.

Bob

 

Thanks for the info, Bob. I'll take a look at that. I appreciate all your help.

Thanks...