Hello, I bought a 1983 toyota pickup a couple months ago and its always been cranking over slow. The starter did go bad but i replaced it and got a new battery and it still cranks over slow every time, and when its cold it cranks for a while before starting even with a couple pumps of gas. It always starts up though. Any ideas? Thanks

 

Re; Slow cranking, I suggest you check or install a thick (as thick as the cable going fro batt positive to starter solenoid stud terminal) ground cable between battery negative and the engine block. Some trucks may not have this. If yours does not or your connections are not bare, shiny metal tightly against bare, shiny metal you are not getting full power to the starter motor.

 

Thank you so much Rad for your advice! I looked and there was just a ground going from the battery to the fender. I went and bought a cable and bolted it to the engine and it fires right up every time.

 

I also suggest you add a starter relay. That's discussed on one of my threads.
Search "clicknocrank", "wiring flaw", "clickonlynocrank", etc

I don't understand why many earlier trucks do not have cables to carry heavy cranking current to the starter. Without it cranking current travels through unpredictable collateral path, i.e., grounding wire for other parts, mechanical parts that HAPPEN to have metal parts bridging fender/body and engine block, etc.
Hoping other owners of 84 and earlier could check their trucks, too.

 

The ground cable on my 84 just goes to the fender, but it still cranks strong and fires up quickly - especially after installing a starter relay..
I did get a longer ground cable and will install it next time I'm under the hood.

 

Out of curiosity, where is the ground cable(s) that connects from the engine to the body on your truck?

I am just curious how Toyota grounded the starter on these models if there is no direct negative battery cable to the block.

 

My 1986


https://photos.app.goo.gl/GfTyDFmkenb9X9cu8

... current travels through unpredictable collateral paths, i.e., grounding wire for other parts, mechanical parts that HAPPEN to have metal parts bridging fender/body and engine block, etc....

 

I can confirm 1 from the back of the engine (maybe the bell housing bolt) to firewall ground - less than a foot long and pretty small gauge, un-insulated, it looks original. I wouldn't be surprised if this one gets deleted or cut when an engine comes out.

There is also a "ground" bolted to the head just below the distributor - it is original, insulated bigger gauge than the other. It goes into the alternator harness so I don't know where it goes.

 

This is what I grabbed at a wreck yard possibly from an 86 - next ime I get into the engine bay I'll install it.

 

The only solid connection to ground from the starter us where it mounts to the engine block.
Starter that I got is 1.4kW
1400 watts ÷ 12 V = 117 Amperes.
The above thin wires are not enough to handle 117 Amperes.
First gen trucks may have less, but I'm pretty sure return current to batt negative passes through those plus other collateral paths, like metal parts that just happened to bridge the engine block and battery negative. Not sure which ones, so not having a dedicated cranking ground cable is electrical Russian roulette.
Another proof that Toyoya electrical engineers of those days were not as good as its mechnical engineers.

 

Thanks for the description L5wolvesf.

Yeah, I have no idea why there was no dedicated thick negative cable for the starter for some early trucks.

I would have thought that would have been obvious when designing the electrical system, but I guess not....

 

Considering how many amps the starter draws it is kinda surprising.

There aren't many metal to metal connections between the engine and body/frame. The exhaust may have 1 or 2 but I can't think of any other.

 

Basic question, did you keep the ground going to the fender? Or delete?

 

I kept the cable going to the fender and I bolted the new cable from that same bolt on the fender to the engine.

 

Thanks!

 

Good job, OakdaleBud.
Most electrical in cabin and body use body ground. The fender ground is how body metal is connected to battery negative.
Ideally, however, the block ground should be directly connected to battery negative. I know it had lasted for years, but it's not ideal to have starter current go through the thinner fender ground cable.

 

Sorry about the late response, kinda forgot about this thread since I didn't get an email about it. The cable going from the negative to the fender is the same size ground cable

 

But why not directly from battery negative to block like the newer trucks have? This way absolutely all starter current passes through that cable and nowhere else. That's the ideal setup.
Either way your setup is now electrically better and safer than before.

 

well to be frank the cable we got wasn't long enough

 

OK. LOL!
Still, your setup is now electrically better and safer than before.
Glad you got it fixed.