Won’t start!!!

[1987_345]

Won’t start or turn over. We’re caroling this weekend and may have a little trouble getting going home in the next day or so. May have to just stay here!!!!
I’ve always wondered why there are two starter solenoids on our 1987 345. There’s one on the starter and one on top by the air cleaner. We have the banks power pack so the headers ore there heating things up nicely. But all heat shields are in place and everything is wrapped up nicely for protection. The starter and both solenoids were replaced about 2 years ago but here we are dead again. Why are there two solenoids? How can I hit wire it to get going?

[BayouBiker]

The relay by the air cleaner is to allow for low current through the keyed ignition switch. That relay provides higher current sufficient to power the solenoid magnet that will both actuate the shift lever to engage the clutch and drive gear and push the high current contacts energizing the motor coils.

If the upper relay is bad you can jumper around it with a 10 or 12 gauge wire to energize the lower solenoid. If that one works you will hear the shift arm move and click. If the start brushes or coils are burned out the motor won't turn and a new starter is in your future.

[Air345Fly]

There is another solenoid that can connect the house batteries to the
chassis battery. It is operated by a toggle switch in the glove compartment.
You would use it if you ran the chassis battery down trying to crank
over that big 454. It is a big help on a cold night. This solenoid
is mounted on the back of the battery tray.

[1987_345]

Thanks Bayoubiker. Since both solenoids and the starter were replaced less than 2000 miles ago I’m assuming I may have a short between the key and the upper solenoid. I’ll jump it to get going and when I get home if I can’t find the problem I may have to just put in a started button for reliability. Do you think there is any need to protect the wiring around the starter from the heat of the headers besides the heat shield that was provided?

[BayouBiker]

If the wires are not touching the heat shield, no need. they can touch the engine block etc, no problem. They are good to 90C and the heat shield blocks the radiant energy which is the biggest issue when there is an air gap to work with.

[1987_345]

Ok thank-you. We got home safely. I touched a screwdriver from the small terminal on the left to the large terminal on the left and then turned the key all the way to start. It started right up. I guess I may need to put a jumper between those two left terminals

[1987_345]

I changed my mind on the jumper. I need to trace the wires back and try to locate the trouble. Could anyone provide me with a 1987 starter solenoid/relay wiring diagram?

[BayouBiker]

Glad you made it home and the screwdriver trick indicates the starter and main solenoid is good. I used to use the screwdriver trick all the time back in my high school days and have a couple melted ones to show for it. I was reluctant to suggest that because the current is so high, and crawling under there is nasty. I don't know where to find the service manual and diagrams, but I wish you luck.

[Waipio Rim]

Fwiw, I did not know that this relay existed until a mechanic found it for me. I was in a hurry to get going, he could not find a direct replacement, and I am still running with the jumper that he installed. Please post the solution when you figure it out.

[Boom Sounds]

1987 Service Garage manuals for Electrics, Emissions, Driveability, Unit Repair and Service repair. Look for the P series stuff.


http://www.73-87chevytrucks.com/tech...lete_11x17.pdf

http://www.73-87chevytrucks.com/tech...air_Manual.pdf

http://www.73-87chevytrucks.com/tech...ice_Manual.pdf

http://www.73-87chevytrucks.com/tech...iveability.pdf

[1987_345]

Thanks guys for all of the valuable info. I searched through the existing threads until late last night and discovered some interesting information. Apparently when AS put these units together, they didn't use a very beefy ignition switch and the upper starter relay was a mod to compensate for it. I really don't have much knowledge when it comes to trouble shooting electrical components, but I can change out parts! What I also found were a couple of threads that talked about replacing the factory starter with a 1995 or later high torque starters. They are smaller, stronger, and claim to draw less energy to complete the task of spinning these big 454's. The space savings will help me keep out of the header tubes as well. I gathered up all of the parts and will attempt the change over this weekend if the rain holds out. I'll keep you posted. Thanks again, Kenneth

[BayouBiker]

The high torque starters are better, Honestly mostly because they are smaller, but hey any port in a storm so.... remembering back to my drag racing days. they still pull a lot from the ignition so the key ignition switch is remains the weak point.

[Boom Sounds]

Suggest add heat shield if not already in place. I think still useful for smaller starters. Lack of heat shield is common cause of large starter failure as they warp and suffer heat damage

[PeterH-350LE]

Best to get rid of the stock type starter asap. I just replaced mine with an expensive Mean-green. Cheaper versions are available, but this is the end of your troubles. Either way, take your time to make sure your new starter is shimmed out properly, especially if the engines was rebored

https://www.mean-green.com/searchqui...words=MG6510HD

[1987_345]

Right. The banks system provided a heat shield which I did put on but I'm figuring I may need to modify it to fit the smaller starter

[1987_345]

Ok so here's how it went yesterday. The project to replace the starter took about 3 hours but it also included an oil change. First I disconnected the cranking battery and replaced the faulty starter relay which is the one next to the air cleaner. I would to also note that I decided to remove the rubber pad that is between the relay flange and the channel piece that it's mounted to. I think that it's so important that this component has a good ground that I don't want any rubber in the way. So I made a spacer out of steel that would give it the height it needs but help it be super conductive as well.

Next was the starter which was a 1995 or later model starter. I removed the OEM starter as well as the heat shield that came with the headers. I also noticed the old starter had two shims under it that I set aside to use with the new one, only the shims didn't fit the new starter and the new starter didn't come with any shims of it own. When I tried to put the new smaller hi-torque starter on, the holes wouldn't line up because of the torque converter pan so I removed it. Without the pan in place the new starter bolted up perfectly, and without any shims. I reconnected the wiring just as it was on the old one and reconnected the cranking battery. Then I disconnected the ignition at the distributor because I didn't want the engine to start as I tested it, I just wanted to see how it cranked over for now. To my surprise when i turned the key the engine turned over perfectly and whisper quiet! I reconnected the ignition plug at the distributor and started the engine. It operates perfectly and has never turned over this smoothly and quietly since I've owned the MH.

Now for the heat shield. I'm not sure I even need it anymore because the closest header tube is now over two inches away from the starter and I would think that enough heat would dissipate given that much space even sitting still in the heat of summer. But I was able to trim it up a little with tin snips and bend it making it smaller and then reinstalling it. I had to mount it under one of the starter mounting bolts and am not completely happy with that install. I fear t will vibrate and ultimately fail. I think I may make an additional bracket for it to go under the bolt for the transmission dip stick tube. But before I go to that much trouble I will probably see if I can find a factory heat shield for the smaller starter.

Lastly the torque converter pan. All I had to do with it was trim about .25 of an inch around the hole that the starter pokes through, then it when back on fine.

I'm very happy with this mod and hopefully the starter problems I've been plagued with for awhile are finally over. We'll see. Thanks again for all of your help and I hope this conversion can help you all as well.

[PeterH-350LE]

Originally Posted by 1987_345

... I had to mount it under one of the starter mounting bolts and am not completely happy with that install. I fear t will vibrate and ultimately fail. I think I may make an additional bracket for it to go under the bolt for the transmission dip stick tube. But before I go to that much trouble I will probably see if I can find a factory heat shield for the smaller starter.
...

When I modified the original heat shield for the smaller starter, I left a 1" strip of metal in the back that I bent 180degrees and used a big hose clamp to tighten it to starter body. Worked well.

[Waipio Rim]

What relay did you find as a replacement? Mine had no markings.

[1987_345]

It's actually a standard Ford relay. I think they are universal having two battery posts and two smaller posts. The only difference in most of them is how they mount. Just take it into your local parts store and they can match it up for you. They're around $8

[Waipio Rim]

Thanks. Mine is different, but I will have to figure out the wiring and use one like yours.