Hi Fellas, new member here. I just bought a 94 F150 fixer upper for a work truck. It is pretty basic: regular cab, long bed, bench seat, hand crank windows, rubber floor mat, etc. just like I wanted...no fluff just a simple truck. It even has a lift gate that might come in handy. It also has the 4.9L I6 engine I've heard so much about and have always wanted to try. The transmission is the automatic, not sure of the name or designation.

The problem: I noticed when I start the truck, that NONE of the dashboard warning lamps come on at all. The dash illumination lights work just fine and the truck starts and runs fine. I'm thinking, since they all are not working, that it must be one common problem like something unplugged or a ground not making connection.

Thanks in advance for any advice you can throw my way.

 

Check fuses.
Pull the cluster, and check and replace the bulbs.
If all the bulbs are good, then while its out visually inspect the connector and traces.
Also while its out, use a volt meter, get a schematic and verify power is getting to the connector.

 

Ok, I found the #17 10 amp fuse blown, so I replaced it. The warning lights came on when I turned the key. I tried to start it and it cranked but didn't start then the whole electrical system went dead as if the battery was disconnected. The new #17 10 amp fuse didn't blow. I disconnected the battery.

I checked all fuses again and found #16 15 amp fuse (data link connector) blown, so I replaced it. The power came back on when I connected the battery again. I turned the key and the warning lights came on again, so I tried to crank it. The power immediately went out again, but now no fuses are blown.

Now, I'm REALLY stumped.

 

Check your battery cable clamps. If they have the "repair-style" clamps, they'll always cause trouble. You can clean them and get them to work for alittle while, but they'll eventually leave you stranded.

 

I just came in from the shop. I had to check it again even though it's 1:30 am and I'm old and tired. You hit the nail on the head!!! This truck does have those repair style clamps and they looked terrible. In addition to that, the ground wire going from the negative terminal to the fender ground next to the battery was spliced in the middle and taped. All connections looked pretty corroded. I cut and stripped the ends and replaced that spliced ground wire and hooked it back up. I turned the key to the accessory position right before cranking and had power to everything. I also noticed the voltage gauge working for the first time since I bought the truck. I figured I'll wait until tomorrow to try to start it because I'm pretty tired and don't want another disappointment right now. It'll be easier after some rest and with some daylight. I'll post again tomorrow with the results...good or bad.

Thanks guys!! I'm feeling a little more hopeful now.

In edit: I almost forgot, when I redid the battery connections I disconnected the main power wire to the liftgate on the back of the bed thinking it might be causing a problem and left it off. I'll check that wire tomorrow.

 

Morning update: Well, it started up and it looks like everything is working as far as I can tell with a quick glance. Shortly, I'm going to check it over a little more thoroughly and test drive it.

It looks like it was a couple of blown fuses and some corroded battery and ground connections causing the problem...possibly triggered by a problem with the power wire running from the pos battery post to the liftgate on the back.

It seemed to idle a little rougher, but maybe it's a situation of the computer needing to relearn how to run things?

 

If it's running rough, do the basic tests.
1. Check for engine codes, even if you're check engine light is not on.
2. Check your timing. It should be 10°btdc with the spout connector removed.
3. Check your fuel pressure on both tanks.

4. Perform a cylinder drop test to see if one cylinder isn't contributing.
5. Check your compression.

 

That all looks fine. The idle roughness I'm talking about is probably normal except that it fluctuates occasionally. I've been driving a Tundra with the 4.7L that has almost no vibration at idle. I used to have to look at the tach because I thought it died.

Could the MAP sensor cause the idle fluctuation?