My starter was fine, until the weekend.

The weather was nice and I decided to take a drive; started fine. when I got to my destination, I turned the key and it attempted to start the car and the battery cuts off.
I have a 60 amp fuse on the red wires going to the battery, check the fuse it wast toast. I replaced the fuse and it blew it instantly as soon as I turn the key on.
Since there is a wire coming from the the main fuse that I installed from the battery to my amp and air horn, I isolated the wire and replace the fuse again the car starts fine.

When I got home, I installed a dedicated fuse for that amp wire.

Since then, the starter becomes a hit and miss. sometimes starts on the first try, sometimes i have to turn the key on and off before the starter spins. Sometimes it would start spinning for a short time and stops before the engine can start.

The starter positive wire is straight from the battery.
I know that there is an issue with the 74's where a relay is installed, but why would it burn the fuse to begin with?

All my grounds are intact.

Any ideas??

...you've been driving the heck outa this car...I'm more curious what changed???

Ray,

He'll yeah!

Nothing changed other than removing the transmission for new front and shift console seal replacement .

I will check my ground strap today, I am sure it is intact. Still that would'nt explain the blown fuse issue.

Cracked Ignition Switch can cause intermitent problems until it totally stops working?

Has the seatbelt interlock circuit been bypassed yet?

Yes it has .

I'm somewhat unclear with the order of events that took place when this fuse blew. You were starting the car (key in the start position) then all the sudden the starter quit with the key still in the start position? At this point, you found a aftermarket inline 60 amp fuse connected to the battery that was blown? Then after replacing this 60amp fuse, the car will now crank over? If this is true, it sounds like you had over 60 amps running thru your ignition switch, which doesn't sound good. I would suspect a ruined or intermittent contacts within the switch.

Tim,
correct! the 60 Amp fused was added by myself after an incident with my other teener where the one of the red wire was shorted and burnt, I had to replace the harness.

the car ran fine for the past year with that fuse, Nothing has changed. I started the car once a week during the winter without any issues.

The weather was nice I decided to take it out for the first time. i drove if for about 10 miles to my friend's house. 10 minutes later< tried to start, the starter turned once and the power cuts off completely.

I checked the fuse and it was toast. I replaced the fuse and the issue repeated itself.


Since I have a small amplifier for the radio, I decided to isolate the wire and replaced the fuse and this time it did not blow the fuse, But.......

to get it started it's a hit and miss. sometimes i have to turn the key on and off 3 to 4 times before it cranks and sometimes it cranks in one shot.

My question is, can a starter going bad blow that main fuse?

I'm not familiar with the Djet start circuit setup. The start wire still runs thru the relay board via the 14 pin connector and out the 12 pin connector. It may be worth removing both connectors, and re-seating them 20-30 times each. This way, the connection will self etch thus eliminating any problems (if you have any here).
I think you already isolated your problem, by putting the amp on its own circuit. But, I think the damage is already done with the ignition switch. To verify, pull off that 14 pin connector, and measure for 12vdc at pin 1 on the connector (not pin 1 on the relay board) while the key is in the start position. If you do see 12vdc while in the start position, try jiggling the key or whacking on the steering column, while watching for any voltage drop at the meter. It would also be good to ohm out the relay board, pull off the 14 pin and 12 pin connectors, and put one meter lead on pin 1 (on the 14 pin socket on the relay board) and the other meter lead on pin 6 (on the 12 pin socket on the relay board) you should measure close to 0 ohms. You may wanna double check the bypass job on the seatbelt interlock circuit. I have seen PO's use a wire nut to tie the 2 yellows together. I'm not a fan with this type of repair, just for the fact that the wire nut could come off and cause a short. I know it is a pain in the ass to solder these two wires, due to their size. Also, if it is soldered, it's easy to have a cold solder joint if the soldering iron was undersized. It's worthy to take another look at that connection. All and all, I'm leaning towards the ignition switch being the culprit.

Thanks. Will follow your advice and do more troubleshoot Friday . I will report the results.

The starter going bad could blow that fuse, depending on if it shorts or open circuits. After you removed the amp from the circuit you said you can get it started sometimes, might have done damage to the starter relay. Either way it seems you are developing a ground in the starter circuit if it used to work and now, suddenly, you are blowing fuses with everything else the same. Fuses don't blow for now reason.

If you are blowing a 60 amp fuse with ~12.5 volts then your system resistance when cranking is <0.2 ohms. The only issue with measuring the entire resistance of your starter circuit is that normally the resistance of the motor is low with no current flowing through it and increases once current is driving the motor.

I'd just start by removing the starter relay and measuring resistance from the starter relay incoming + to a ground (it should be pegged high)

If that checks out remove the + wire from the starter and measure resistance from the starter relay output pin to ground (again should be pegged high).

If neither of those have grounds I'd suspect you may have a developing issue with your starter. It could have short circuited. You can try to read the resistance of the windings by measuring resistance using your lowest setting. Measure from the + to the - (or case of the starter if no - ) a resistance of 0 means you may have short a circuit, you should get a low resistance but not zero.

Or if you have a spare starter relay just try throwing that in but you could fry it.

Good luck!

Great info and thanks .

Where is the starter relays located ?

I don't have a 914, only an engine from one so I'm not sure what's on your relay panel but what I described is in general how the starter circuit functions. If it works like the 912 then the ignition switch serves the function of the relay. You can "fix" this by wiring in your own starter relay so that your ignition switch contacts will take less current/wear.

I'm sure someone will chime in, but if you check out this diagram, number (2) is the starter, looks like you may have a relay board (number (90) in the bottom left).


With Starter:
http://members.rennlist.com/warren/914wiring2.jpg

Directory of diagrams:
http://members.rennlist.com/warren/

Update:

I started the car Friday and noticed a noise on the starter after starting for about 8 seconds, then it went away. keep restarting and it has not happened since. I think that it is getting stuck on the flywheel causing overload and blows the fuse. (is that a possibility?) I went ahead and swapped with the starter on my other teener, it is only about a year old and about 1000 miles on it. I am not sure if the issue is solved, but so far so good.
we will see what happen.

any scarring/marring on the shaft that would indicate an uneven mating of the two surfaces?

No, no sign of any wear of grind.

bad solenoid ?

I am happy to report that after replacing the starter, I have been driving the car. I made frequents stops to have a chance to crank the starter as much as possible and so far no issues.

I concluded that it was the load on the stuck solenoid that a cooked the 60 amp fuse.

excellent...thanks for the follow up info!

No problem Ray, I would like to add that he load from the amp added to the stuck solenoid is what caused the fuse to be burnt . If it was only the starter on that fuse, I don't think it would burn the fuse.