I've been having warm start issues for the longest time. 86 F-250 351W. In the morning the truck would start fine. Once I would stop, I would need to let the truck sit for 20-30 minutes before it would crank back up again. On a warm start the starter would drag very slowly a couple of times and that's it. I've had the battery tested, alternator tested, starter tested twice and all came out fine. I'm being told it's the starter. While I'm having the starter rebuilt, I'm trying to go over the wiring. I can only find 1 ground, Battery to engine. I know I need a couple more grounds. Can someone tell me which grounds and best place to attach them? Sorry for the long post and thanks in advance.

 

Before you do anything, make sure all your connections at the battery and the place where the negative battery cable attaches to the engine are clean and tight. If wire ends are corroded or dirty, you can get some steel wool or a wire brush and clean them up. This way you have good connections to start with.

There should be a ground strap or wire (most likely a strap) running from a bolt on the intake manifold or some other metal part of the engine, to the firewall. On my '81 F-150 302, the ground strap ran from right behind the carburetor to the firewall above and slightly left of the engine. I replaced the ground strap on my '81 with an actual wire, and I've had no issues. You can clean the area where the strap/wire contacts too.

I've read about people running a ground cable from the engine to the frame, or from the battery to the frame. You could probably just get a cable and connect one end to the same place that the main ground cable from the battery is connected, then run the other end to the frame. Both cables would be directly contacting each other, so you would have full voltage in both cables. It would also look better than having a second cable running from your battery.

Also, have you had your starter solenoid checked to make sure it's good?

 

Had the same problem. I threw parts at it, which all seemed to make sense at the tiem, and none of them solved it. I still am not sure what the problem was, and I did all new cables, starter, relar, ignition switch, and ignition module. I feel like a rookie! (Not that there is a problem being one). Make sure you have the ground to the firewall and you might go from the engine to the frame as well. Those are the only two things I have not done yet.

If it is the factory ground cable, it probably goes from the battery to the engine to the frame. People seem to report having problems with those cables.

 

Also check to see if the starter is getting "heat soaked" That will cause a slow starter with engine hot. On some vehicles there was a heat shield between the starter and exhaust system or the exhaust has moved closer to the starter cooking it.

 

Ford used to use .. and might still use im not sure never bought a NEW truck before .. but they used a ground wire that went down to the frame, about 2/3 the way down they striped the wire and put a bare metal clamp around it to the motor block. I live in a salty state and I tell ya that clamp with NOTHING to protect it would go to crap fast. I had a problem in 86 .. hit a bump and half the lights in the cab go out, radio stops, ect. At some point the cable / wire just breaks in two from salt and weather. I ended up running a #4 off the battery down to one of the starter ears, then another #4 from there over and bolted it to the cab floor support. Cured a TON of my electrical problems.

 

Well guys I think I solved the problem. I knew deep down it had something to do with the grounds. I held off taking the starter to get rebuilt and went to work on the truck. I cleaned all connections and made sure they were nice and tight. I had to trim wires to expose fresh uncorroded wires which I had done before and didn't solve my problem. I noticed I only had 1 ground wire (battery to engine). I looked under the truck near the frame rail and saw a torn wire. Assuming it was a ground wire, I went ahead and added another ground (engine to frame rail). I cranked the truck and let it warm up. I shut the truck off, gave it a minute, and with fingers crossed cranked it up. Vroooom it started right up WooHoo. I've been dealing with this problem for years and just sort of accepted it and worked around it (made sure to only use the truck if I was only going from point a to b, if I had to make a quick stop in the truck, I had to leave it running,...). I would like to thank yall for your help. Would like to add an engine to firewall ground (lower intake bolt to firewall???). Would that be too much or should I leave well enough alone and enjoy the truck. One last question, I noticed on my stang I have a small ground wire going from my battery to a nearby body bolt should I put one on the truck? Thanks and sorry for the long post but now I don't have to worry about shutting the truck off when getting my brake tag.

 

When it comes to electrical, you can never have too many grounds. Add the firewall one and even the other one if you want.

 

There should have been one there... Or maybe they did not do that till later on? It will not hurt. Most of your Electrical up front ( head lights, horn, turn signal, ect ) pull the ground off the front clip or body ground so it will help out there.