Starter fuse blowing

[athoose]

My inline fuse between the battery and starter relay is blowing after a couple of start ups. To be more specific sometimes it melts after a couple start ups sometimes I'll get half a dozen, it just varies. About a year ago i switched to the Saturn alternator and got a new starter. Everything was working great for about six months. But I let it sit and maybe laid on the cranking too long to get it running. Ever since it's been melting that fuse. Any ideas?

 

Thanks in advance!

[datzenmike]

I'm guessing that you have installed a 'hot start relay'?

 

What gauge wire did you use?

What amperage fuse are you using?

 

If the wire is thick enough you may be able to go to a higher amp fuse.

[banzai510(hainz)]

15 minutes ago, athoose said:

My inline fuse between the battery and starter

Is there really a fuse between the battery and starter?  I know theres a fuse between the starter and fuse box. Or am i just misunderstanding here

 

for a hot start most people dont use a Fuse in the relay. I dont.. I know it shows it in this photo but most people dont use one but 15amp fuse should be more than enought. I would ck for dirty and clean good crmp connections, tight

 

Edited November 17, 2022 by banzai510(hainz)

[datzenmike]

A fuse between battery and starter? Never. It would have to be 1000 or more amps or it would blow and not needed. The start signal to the starter solenoid from the ignition is already on a fuse. This leaves a hot start relay as the only possible excuse for an inline fuse..

[athoose]

This is what i have. it's between battery and relay. Sorry for the misunderstanding. I'll clean stuff. Why remove?

[banzai510(hainz)]

since your using a thick red wire from battery to the fuse then to the relay I would just keep using the red thick wire to the selinoid. contacks 30 and 87.

 

also to make the CLEANER LOOKING  you can just go to the starter post(big round lug) to get the 12volt from battery and keep the wire mess alot lower /shorter to look better.

 

 

be honest I never knew how small the orginal wire was going to the selenoid and they seem to work for 30yrs. I think that small balck wire on the selinoid would be fine.  maybe selinoid is getting dirty and drawing alot more current. But Im only guessing.

 

clean contacks. all of them

Edited November 17, 2022 by banzai510(hainz)

[Stoffregen Motorsports]

Right, in normal situations, a starter solenoid shouldn't draw many amps at all. But, if it is old or dirty or starting to go bad, it may be causing a short...?

 

When I do that mod, instead of using a small Bosch style relay, I use a Ford style continuous duty solenoid. They are beefy and can withstand mega amps.

[datzenmike]

Yellow is a 20 amp fuse. That shouldn't be blowing.

 

 Why is there a thinner Green wire to the starter solenoid??? Should be the thicker red wire you have the fuse on.

[banzai510(hainz)]

28 minutes ago, datzenmike said:

Why is there a thinner Green wire to the starter solenoid???

Yes that what I thought but the stock wire isnt much bigger either if not the same what he has. I thinbk that wire would cook also if that fuse pops.

must be a Highresisitive short in that system. either bad connection or the selinoid

[athoose]

I used the thin green wire because the original was about the same gauge, I'll replace with thicker.

 

Hainz, If that fuse wasn't there I'd be burning something up, right?

 

12 hours ago, Stoffregen Motorsports said:

Right, in normal situations, a starter solenoid shouldn't draw many amps at all. But, if it is old or dirty or starting to go bad, it may be causing a short...?

 

When I do that mod, instead of using a small Bosch style relay, I use a Ford style continuous duty solenoid. They are beefy and can withstand mega amps.

 

New solenoid but I'm wondering if I might have damaged it cranking too long. I think i still have my old one, which was good. I'll swap if other solutions don't fix it.

 

14 hours ago, datzenmike said:

I'm guessing that you have installed a 'hot start relay'?

 

What gauge wire did you use?

What amperage fuse are you using?

 

If the wire is thick enough you may be able to go to a higher amp fuse.

 

Yes, 20 amp fuse. What's about the highest i should go? I have some 30 amp spades but other types that are higher, 50,60, or so.

 

Thanks all!

[datzenmike]

That thick wire is capable of much more than 20 amps. Obviously that thin green one survived it. Try 25 amp fuse.  If you have the original starter put it back in.

[banzai510(hainz)]

12 hours ago, athoose said:

Hainz, If that fuse wasn't there I'd be burning something up, right?

Only that wire that is Power from the relay. Pretty much that thin green wire is now your FUSE. Its separated from the Datsun wires in a harness so it would NOT burn up other wires in the car.bUT EZER TO REPLACE A FUSE INSTEAD OF A WIRE ON THE SIDE OF THE ROAD

 

Like I said clean the contacks.

 

If car is timed and runing well it should start up fine. I wouldnt lay into it like 10sec or longer.

Im thinking 3-5 secs if that once the gas is too the carb (if sitting for a long time.

 

15amp FUSE     should be more than enough for a selinoid. otherwise I say selinoid is drawing to much power for some reason. Comtacks must be wearing out(carboned up)

Edited November 18, 2022 by banzai510(hainz)

[datzenmike]

The green wire survived what would blow a 20 amp fuse so probably ok but I would replace with the thicker gauge because easy enough to do. 20 amps seem a lot just for the solenoid but may be correct. The stock wire from the ignition is directly from the fusible link and not really fused so 20 may be normal. Try 25 amp fuse and bigger wire to replace the green one.

[Stoffregen Motorsports]

10 hours ago, athoose said:

I used the thin green wire because the original was about the same gauge, I'll replace with thicker.

 

Hainz, If that fuse wasn't there I'd be burning something up, right?

 

You definitely have something funky going on here.

 

What would happen if you reconnected the original starter solenoid wire to the starter solenoid? Maybe you could try that, and try putting an inline fuse on that wire just for the test. If you blow a fuse then, then yes, there is probably something wrong with the starter.

 

A ton of cranking wouldn't hurt the solenoid, it would hurt the motor instead. At least in normal situations. Think of a solenoid as a relay. One side should not be in contact with the other side. If there is debris inside the solenoid (like thick heavy grease, gunk, a broken/frayed wire) then the two side might make contact. Likewise debris could also make a short.

[athoose]

13 hours ago, datzenmike said:

That thick wire is capable of much more than 20 amps. Obviously that thin green one survived it. Try 25 amp fuse.  If you have the original starter put it back in.

 

The starter is shot, solenoid was okay though. Found a good starter alternator place locally to rebuild recently but at the time Napa had one for 40.

[athoose]

4 hours ago, banzai510(hainz) said:

Only that wire that is Power from the relay. Pretty much that thin green wire is now your FUSE. Its separated from the Datsun wires in a harness so it would NOT burn up other wires in the car.bUT EZER TO REPLACE A FUSE INSTEAD OF A WIRE ON THE SIDE OF THE ROAD

 

Like I said clean the contacks.

 

If car is timed and runing well it should start up fine. I wouldnt lay into it like 10sec or longer.

Im thinking 3-5 secs if that once the gas is too the carb (if sitting for a long time.

 

15amp FUSE     should be more than enough for a selinoid. otherwise I say selinoid is drawing to much power for some reason. Comtacks must be wearing out(carboned up)

 

I let it sit and the gas in the carb evaporates, so i have to crank it to fill up bowl. Usually, i give it a few cranks before it fills. The weber seems to take longer to fill than the original.

 

New solenoid.

[athoose]

2 hours ago, Stoffregen Motorsports said:

You definitely have something funky going on here.

 

What would happen if you reconnected the original starter solenoid wire to the starter solenoid? Maybe you could try that, and try putting an inline fuse on that wire just for the test. If you blow a fuse then, then yes, there is probably something wrong with the starter.

 

A ton of cranking wouldn't hurt the solenoid, it would hurt the motor instead. At least in normal situations. Think of a solenoid as a relay. One side should not be in contact with the other side. If there is debris inside the solenoid (like thick heavy grease, gunk, a broken/frayed wire) then the two side might make contact. Likewise debris could also make a short.

 

Well maybe i broke the starter cranking?

 

I'll give the original starter solenoid wire a shot, see what happens.

 

That relay, is probably 40 yrs old too, maybe it's a factor? I can test it, iirc. 

[Stoffregen Motorsports]

Come to think of it, just last summer I fried the solenoid on my tractor starter by hooking up the wires incorrectly. I was just trying to test the starter and the solenoid let the smoke out. So yeah, solenoids do go bad, if you do stupid shit.

[datzenmike]

Show of hands. Who has not had their battery bungeed down properly and it falls against the body metal on a turn and the positive terminal grounds (causing a minor fire) and the only connection to the negative terminal is down the throttle cable which heats up and melts the sheath which cools and locks the gas pedal at idle???? 

 

OK, who has replaced the throttle cable and then a month later done it again?