Bypassing Ignition Wiring

heygibb · November 20, 2008

I'm working through bugs on my recently acquired 89 sierra 4wd. This past week, the starter wouldn't turn over. After ruling out the battery, I removed the starter and bench tested it...all ok. I re-installed it but it still would not turn over. I turned the ignition key on and then shorted the two terminals on the starter and it started right up.

I decided to replace both the ignition key cylinder and ignition switch, hoping that was the problem. Unfortunately, I still have the same "click" when the key is turned.

I've decided to wire the two terminals from the solenoid to a dash mounted switch and bypass the normal wiring. Is there something else I should check out or replace before going this route? It's a hunting/fishing truck, so adding the switch doesn't bother me. It just seems to be the easiest way to overcome the lack of power getting to the starter.

grassy ass, amigos!

grampadirt · November 20, 2008

I'm working through bugs on my recently acquired 89 sierra 4wd. This past week, the starter wouldn't turn over. After ruling out the battery, I removed the starter and bench tested it...all ok. I re-installed it but it still would not turn over. I turned the ignition key on and then shorted the two terminals on the starter and it started right up.
I decided to replace both the ignition key cylinder and ignition switch, hoping that was the problem. Unfortunately, I still have the same "click" when the key is turned.

I've decided to wire the two terminals from the solenoid to a dash mounted switch and bypass the normal wiring. Is there something else I should check out or replace before going this route? It's a hunting/fishing truck, so adding the switch doesn't bother me. It just seems to be the easiest way to overcome the lack of power getting to the starter.

grassy ass, amigos!

You might investigate the neutral safety switch...it's happened to me once

Gary

heygibb · November 21, 2008

You might investigate the neutral safety switch...it's happened to me once

Gary

Thanks.

I'll look into that before proceeding. It's actually cheaper than the switch I was going to install.

grampadirt · November 26, 2008

You might investigate the neutral safety switch...it's happened to me once

Gary

Thanks.

I'll look into that before proceeding. It's actually cheaper than the switch I was going to install.

Just curious if you got the problem solved

heygibb · November 26, 2008

You might investigate the neutral safety switch...it's happened to me once

Gary

Thanks.

I'll look into that before proceeding. It's actually cheaper than the switch I was going to install.

Just curious if you got the problem solved

I feel I will probably rig the bump switch. I traced the purple wire from the solenoid to a wiring harness connector mounted under the AC tank (don't know it's accurate name, but it frosts over from the freon inside). I thought it would lead me to the neutral safety switch. I will ask the parts man tomorrow if my truck has one. There is no mention in either of my shop manuals of it. Was the nss you had in your '95?

I will report back when I find something out. What puzzles me, is last week, I drove that truck out of town for a full day and it started a half a dozen times after stops I made, w/ no hiccups at all. Then after dark, leaving a restaurant, it required me to short the solenoid terminals to start. Now it won't start w/out doing that...annoying to say the least. I don't mind running the bump switch circuit but I'd really like to know the actual cause of my gremlin.

Tim

grampadirt · November 26, 2008

You might investigate the neutral safety switch...it's happened to me once

Gary

Thanks.

I'll look into that before proceeding. It's actually cheaper than the switch I was going to install.

Just curious if you got the problem solved

I feel I will probably rig the bump switch. I traced the purple wire from the solenoid to a wiring harness connector mounted under the AC tank (don't know it's accurate name, but it frosts over from the freon inside). I thought it would lead me to the neutral safety switch. I will ask the parts man tomorrow if my truck has one. There is no mention in either of my shop manuals of it. Was the nss you had in your '95?

I will report back when I find something out. What puzzles me, is last week, I drove that truck out of town for a full day and it started a half a dozen times after stops I made, w/ no hiccups at all. Then after dark, leaving a restaurant, it required me to short the solenoid terminals to start. Now it won't start w/out doing that...annoying to say the least. I don't mind running the bump switch circuit but I'd really like to know the actual cause of my gremlin.

Tim

Actually the safety switch was on my 77 GMC.,you just reminded me to ask if your truck is an auto.,it should have one.The switch is on the steering column near the floorboard and looks like a half-moon with a slot in it.The next time you try to start it turn the key to start and move the gear selector around a little,keep your foot on the brake just in case it starts in gear... Gary

heygibb · November 26, 2008

Actually the safety switch was on my 77 GMC.,you just reminded me to ask if your truck is an auto.,it should have one.The switch is on the steering column near the floorboard and looks like a half-moon with a slot in it.The next time you try to start it turn the key to start and move the gear selector around a little,keep your foot on the brake just in case it starts in gear... Gary

Thanks for the advice. I have AT. I have tried to get it to turn over while wiggling the gear shifter in park and in neutral...no change. I was going to the parts place later to ask if they had the switch, but I think I'll take a look at my column and see if I see the part.

I had a chance to check for the neutral safety switch and found it. It's a weird designed thing that is a little tricky to remove, but I got it out. The replacement I picked up at auto zone has an extra spade connection on it. The counter guy couldn't come up with a guess as to why it was there except to say that it looked like a ground connection. I decided to get the part anyway and take my chances. I'll try to get it installed over the next couple of days. Tomorrow might be kind of busy 'round here. Happy Thanksgiving everybody.

Tim

'

grampadirt · November 27, 2008

Actually the safety switch was on my 77 GMC.,you just reminded me to ask if your truck is an auto.,it should have one.The switch is on the steering column near the floorboard and looks like a half-moon with a slot in it.The next time you try to start it turn the key to start and move the gear selector around a little,keep your foot on the brake just in case it starts in gear... Gary

Thanks for the advice. I have AT. I have tried to get it to turn over while wiggling the gear shifter in park and in neutral...no change. I was going to the parts place later to ask if they had the switch, but I think I'll take a look at my column and see if I see the part.

I had a chance to check for the neutral safety switch and found it. It's a weird designed thing that is a little tricky to remove, but I got it out. The replacement I picked up at auto zone has an extra spade connection on it. The counter guy couldn't come up with a guess as to why it was there except to say that it looked like a ground connection. I decided to get the part anyway and take my chances. I'll try to get it installed over the next couple of days. Tomorrow might be kind of busy 'round here. Happy Thanksgiving everybody.

Tim

'

Good Luck Tim,I hope this will fix the problem..my fingers are crossed

Gary

heygibb · November 27, 2008

Good Luck Tim,I hope this will fix the problem..my fingers are crossed
Gary

Gary,

Here is a side by side picture of the old and new switch. The new one has an extra spade connection. Anyone know what I should do with it? I thought maybe I'd run a ground wire to it, if it was required for the switch to work. The problem with that is I won't know if the switch needs the ground to work or not if my truck still won't start. I guess I could rig a temporary ground to it w/ an alligator clip to see.

One thing I noticed on the old switch is the ignition spades (the pair in the middle) aren't very clean. I'm hoping that is where the problem is/was.

I'll post what I find out after I get a chance to work on it. It's a $10 part.

Thanks

Tim

http://www.gm-trucks.com/forums/uploads/12..._365_230097.jpg

grampadirt · November 27, 2008

Good Luck Tim,I hope this will fix the problem..my fingers are crossed
Gary

Gary,

Here is a side by side picture of the old and new switch. The new one has an extra spade connection. Anyone know what I should do with it? I thought maybe I'd run a ground wire to it, if it was required for the switch to work. The problem with that is I won't know if the switch needs the ground to work or not if my truck still won't start. I guess I could rig a temporary ground to it w/ an alligator clip to see.

One thing I noticed on the old switch is the ignition spades (the pair in the middle) aren't very clean. I'm hoping that is where the problem is/was.

I'll post what I find out after I get a chance to work on it. It's a $10 part.

Thanks

Tim

http://www.gm-trucks.com/forums/uploads/12..._365_230097.jpg

Good morning and Happy T'Day,I did a little searching on Auto Zone's website and found the part you have in the pic.I also found that certain year's switches had the back up lights incorperated into the switch,maybe that's what that extra spade's for...dunno.Go to their website and check out their online repair manual.....pretty good reading there.

Gary

heygibb · November 29, 2008

Good Luck Tim,I hope this will fix the problem..my fingers are crossed
Gary

Gary,

Here is a side by side picture of the old and new switch. The new one has an extra spade connection. Anyone know what I should do with it? I thought maybe I'd run a ground wire to it, if it was required for the switch to work. The problem with that is I won't know if the switch needs the ground to work or not if my truck still won't start. I guess I could rig a temporary ground to it w/ an alligator clip to see.

One thing I noticed on the old switch is the ignition spades (the pair in the middle) aren't very clean. I'm hoping that is where the problem is/was.

I'll post what I find out after I get a chance to work on it. It's a $10 part.

Thanks

Tim

http://www.gm-trucks.com/forums/uploads/12..._365_230097.jpg

Good morning and Happy T'Day,I did a little searching on Auto Zone's website and found the part you have in the pic.I also found that certain year's switches had the back up lights incorperated into the switch,maybe that's what that extra spade's for...dunno.Go to their website and check out their online repair manual.....pretty good reading there.

Gary

Well, I was convinced once I hooked the switch up, I'd have a good ignition and starter turnover. Unfortunately, that was shortlived!

I hooked up the electrical connectors, w/out actually mounting the device, and tried to start the truck. No dice. I then slid the moving tab around to different spots, and tried again. No dice. So, that switch isn't going to solve my problem.

One thing I haven't done is detach the ground to the block, clean it and re-secure it.

The other grounds under the plastic cover under the hood are good connections.

I'll post when I get a chance to do that.

Thanks

Tim

superjim · November 29, 2008

Are you SURE that the solenoid is good? Sounds like a bad solenoid to me.

heygibb · November 30, 2008

Are you SURE that the solenoid is good? Sounds like a bad solenoid to me.

Last week, all I got was a click when trying to start the truck. Well, one of the first things I did was to bench test the starter by placing it in a vise w/ a jumpstarter attached. When I shorted the two terminals on the solenoid, it shoved the pinion forward and retracted ok. I put it back in the truck and it wouldn't start...just a click. So I put the key in the on position and shorted the solenoid terminals w/ a screwdriver. The starter engaged and the engine started. From reading other posts, I decided to change out the ignition switch and the ignition key cylinder to see if that helped. It didn't.

After that, the truck started normally for a whole day on the road (5 or 6 stops and starts) until I headed home from dining out. I had to short the terminals again on the solenoid to get home. Since then, I semi-replaced the neutral safety switch (hooked up but not installed), hoping that was where the gremlin was. It still just clicks w/ the key turn.

Does that still sound like the solenoid is bad? Everytime I have shorted the solenoid terminals, it engaged and the truck started. I'm at the point now of installing a jump switch in the cab to engage the solenoid when I need to start up. I'd rather not do that, if I can fix the problem legitimately. How else am I to test the solenoid?

Thanks

Tim

superjim · November 30, 2008

Are you SURE that the solenoid is good? Sounds like a bad solenoid to me.

Does that still sound like the solenoid is bad? Everytime I have shorted the solenoid terminals, it engaged and the truck started. I'm at the point now of installing a jump switch in the cab to engage the solenoid when I need to start up. I'd rather not do that, if I can fix the problem legitimately. How else am I to test the solenoid?

Thanks

Tim

The solenoid is fairly cheap to replace. And to answer your question, yes.. to me.. based on your descriptions... it could very well be the solenoid.

I have had a couple of trucks that did the exact same thing. They would work great when you shorted them out...but be intermittent when using the key.

The solenoid has a big copper washer inside that transfers the battery voltage to the starter motor. Over time the copper washer gets pitted and corroded and when you turn the key to "START" one of the bad places on the washer is at the CONTACT POINT and current don't flow to the starter motor itself.

The CLICK you hear is the solenoid kicking the bendix into the flywheel. But the big copper washer is not making contact INSIDE the solenoid to give battery current to the starter moter in order to turn it.

If money is tight, you could also try to CAREFULLY take apart the old solenoid and see if the big copper washer is all burnt and pitted up. You may be able to take sandpaper and clean it up enough to make it work for a while.

Anyway, that is what happened to me a couple of times.

You may have another problem, but I would replace the solenoid first and see if that solved the problem.

If so, it would save you all the trouble of running wires and switches.

If not, you ain't lost much, and maybe gain some knowledge about solenoids, because (I don't know about you) but I would take the old solenoid apart and look at it.

One other thing... if your truck has a heat shield between the starter and the exhaust manifold.... DO NOT RUN for a long period of time (months) with it OFF. That lets excessive heat get to the starter and heat is bad for the starter and especially for the solenoid.

heygibb · November 30, 2008

Are you SURE that the solenoid is good? Sounds like a bad solenoid to me.

Does that still sound like the solenoid is bad? Everytime I have shorted the solenoid terminals, it engaged and the truck started. I'm at the point now of installing a jump switch in the cab to engage the solenoid when I need to start up. I'd rather not do that, if I can fix the problem legitimately. How else am I to test the solenoid?

Thanks

Tim

The solenoid is fairly cheap to replace. And to answer your question, yes.. to me.. based on your descriptions... it could very well be the solenoid.

I have had a couple of trucks that did the exact same thing. They would work great when you shorted them out...but be intermittent when using the key.

The solenoid has a big copper washer inside that transfers the battery voltage to the starter motor. Over time the copper washer gets pitted and corroded and when you turn the key to "START" one of the bad places on the washer is at the CONTACT POINT and current don't flow to the starter motor itself.

The CLICK you hear is the solenoid kicking the bendix into the flywheel. But the big copper washer is not making contact INSIDE the solenoid to give battery current to the starter moter in order to turn it.

If money is tight, you could also try to CAREFULLY take apart the old solenoid and see if the big copper washer is all burnt and pitted up. You may be able to take sandpaper and clean it up enough to make it work for a while.

Anyway, that is what happened to me a couple of times.

You may have another problem, but I would replace the solenoid first and see if that solved the problem.

If so, it would save you all the trouble of running wires and switches.

If not, you ain't lost much, and maybe gain some knowledge about solenoids, because (I don't know about you) but I would take the old solenoid apart and look at it.

One other thing... if your truck has a heat shield between the starter and the exhaust manifold.... DO NOT RUN for a long period of time (months) with it OFF. That lets excessive heat get to the starter and heat is bad for the starter and especially for the solenoid.

Very good info. I like to tinker and want to know why things happen as they do.

I'll take it apart and check the washer you refer to. It's a beater and not my everyday truck so time isn't an issue.

I could buy the starter, but hesitated because I didn't want to have the same problem afterward, basically throwing that money away. Since I know absolutely nothing about how the solenoid innards work, this will be an education, as you say.

On another note, there is no heat shield protecting the starter. The wires have the flex tubing around it, but I notice it being in very close proximity to the manifold. I had thought of tieing them off and pulling them a bit farther away after this episode is over.

Thanks again for sharing your experience. I'll post a follow-up when I break the solenoid down. ...probably post a picture of the part, too.

Tim

p.s. Is the solenoid replacable as a separate component anymore?