Datsun Roadster Forum-311s.org

I'm not very electronically inclined, so I was wondering if anyone had an idea what went wrong. I tried to start it twice, it cranked over for a few seconds with no success. I just changed the fuel filter and there wasn't much gas in the line. I turn the key again and nothing. Also, there are no lights, wipers or fan, but the horn works. I checked the little fuse box and all 4 are fine. I went down and crossed the starter posts and got some action. The battery tested 13.2 volts. Is there another fuse box besides the little one on the drivers side of the engine compartment? I did drip a tiny bit of break fluid onto a little relay looking connector right under the master cylinder with wires going to the starter. Anyone have some advice? I just did the breaks and it's not raining! I really want to drive it bad.

Thanks.

It sounds like you lost power to your main circuit. Make sure you have power on all of the screws on the relay box, any without power and something is wrong. Also check the back ignition switch. There should be power there all of the time and as you turn to start, all three terminals should have power...Good Luck! TR

I just read... the ammeter has a habit of frying the primary wires. It caries the full amperage of the battery and is unswitched and unfused between the starter and the fuse box and will fry itself and most of the dash harness faster than you can reach for the key.(which dosent matter anyway) If your lucky the ammeter will burn out and break the conection, if not you will be busy for a long time...

Sounds like the culprit.

I just took a look under the dash and the harnes melted in a few spots. I'm confused because the wires on the ammeter are fine and are direct wired and not conected to anything else. Could this have been caused by replacing the solenoid with one that may not have been correct? It's new and was ratteling a bit before all was lost. I disconected the batery when I switched it. It seems pointles to replace the harness so it can just melt again. I don't think I have the temprament or the bank account for this little machine. Anyone looking for a parts car?

Scotty,

Don't throw in the towel yet! The wiring was a design flaw that takes 15 to ~30 years to fail. Most dash harness' I have dismantled have shown a good bit of melt in that region. I suggest running new fused lines to the gauge so that the current isn't carried in the harness and it is fuse protected.

Your theory that the solenoid might be pulling too much may be true, also...Or the harness was in such a state that the solenoid wasn't getting full power.

Good luck with it and keep looking forward to the great weather drives ahead! TR

Thanks, I'll try not to get despondent about it. Can I get away with just replacing the dash harness(or which ever one it is) or do I have to get all of them?

You only need the dash harness, but I would try replacing whatever looks burnt instead. It will only take an afternoon and cost about $20 for the wire and connectors...

Thanks, I'll give it a shot and see what happens.

I pulled the ammeter wires off the starter and rolled off the tape to discover that there were already fusible links on both wires, and the entire harness is still melted, everyplace. One of the links was toasted too. So, If I put a 50 amp fuse on the ammeter wires, as recommended someplace, will that be too big and not protect the new wiring? I don't know what rating the links are that were in there, they are blue and I can't make out any numbers. Also, am I going to want to pull the dash off to do this? It's melted in about 4 places all the way across.

I drove the car for a little while before the starter and brakes went. The first time around on the starter re-build, the bushings were too tight and it couldn't even turn fast enough to start. I'm thinking now that I may have overworked everything trying to start it 10 times, before I sent it back to be adjusted again.

Does anyone know how much I could exspect to spend having the harness rewired in a shop? I don't want to bring it in, but I'm just worried I'll screw it up. I called a few places, but of course they wouldn't even give me a ballpark number.

Thanks

I replaced all the fried wire and put a fuse in there and nothing, no change. Oh well, time to tow it into the shop. Thanks again for your help.

Scotty,

That is disapointing news. At least you know the harness is patched up, now you are down to that solenoid issue...

You might want to take a wiring diagram printout with you to the shop.

Instead of paying the tow fee, you could try the setup people have mentioned for testing their engines, the bare minimum to get the car started (and run a lead directly to the brake light switch so you have brake lights!). This would give you more time to sort out the issue and or point you in the right direction. A "remote starter button" from the local auto parts store would allow you to crank the engine without having to fiddle with the ignition...

I forget if you mentioned what year your car is? I have a wiring diagram for a 66 I can email you...TR

Also, make extra-sure that the cables are tight on the battery. I've seen more than one case where the cable seemed to be tight, but with a "decent" twist, came right off the post. Or, remove the cables, clean the post and cable connector, and reassemble everything. Sometimes it doesn't take much resistance to block current flow.

I second what Datsunbucky says about the corrosion. To go further, there are two types of corrosion - the white fluffy stuff that everyone has seen and a more sinister version. It turns the lead blackish. It will not pass anything! If the posts and the connectors look dark gray, get out the terminal post cleaner (or a pocket knife!) and scrape them down to shiny silver and try it again. I had a car (1966 Mustang) that would blacken the posts within about 6 months. I kept a pocket knife in the car just to clean them as they would cause the car to not start at the most inopportune times....

Thanks for the encouragement and feedback. The battery is new and probably the only decent connection in the electrical system. The guy I took it to is very good and also very busy. He still hasn't had a chance to look at it yet, but I'll post up the solution to this mystery if it may help someone in the future.

I'm not too good with electrical either but can offer that I had some troubles a while back and it turns out that the fuse block on my 70 showed everything HOT when testing with a test light on the FRONT of the fuse block, but one of the fuses had no power coming out the BACK of that fuse

I disconnected the battery, pulled all the fuses and then buffed all the copper up with a bullet shaped cratex deally on my Dremel tool front and back. Be darned if it didn't fix the problem.

I'd driven my car for a while too before this problem suddenly appeared out of the blue.

My 2 cents worth,

Scott "inching along on the stroker project"