Need help diagnosing start problem

[ChasRob]

Hi Everyone
I have a 2002 Workhorse 8.1L that wont start (obviously). When the key is turned on I get a full dash display, but when moving to the start position it acts the same as a very low battery. The solenoid kicks in and out (chatters) and the dash lights blink on and off with the solenoid.
I replaced the chassis battery with a bigger one and cleaned all the terminals on both the chassis and coach batteries (tried using the emergency boost). Same thing. I then replaced the starter and solenoid as the energizing terminal on the solenoid was burned due to heating up.
I've traced all of the connections to verify they are tight and I'm stymied. Is it possible that the problem is in the ignition switch (not the key part, but the module) or the relay? It just seems like I'm not getting enough power to the soleniod to keep it engaged.

Thanks for responding.

[geofferyh]

I had the same problem last year. I did nothing more than pull the starter relay, lube the socket with electrical grease and plug it back in. Also, I ordered a spare inventory of several relays (they are cheap), just in case.
Starter Relay – Tyco 12193604 (3604) ACDELCO 15-8733
A/C Compressor 12 VDC Relay – Tyco 12193604 (3604) ACDELCO 15-8733
Fuel Pump 12 VDC Relay – OMRON 12177234 (7234) ACDELCO 15-8720
Aux. Electric 12 VDC Fans Relay – Tyco 12193604 (3604), ACDELCO 15-8733
BTSI (Brake Transmission Shift Interlock) Relay – OMRON 12088567 (8567) ACDELCO 15-8571
A/Trans Shift Lk Cont SCL Relay (above BTSI) – OMRON 12077866 (7866) ACDELCO 15-5671

[tomwalt]

For a starter, I would clean all grounds at battery and chassis connections.
Look for corrosion within the battery ground (and hot) cable connections where the cable crimps to the battery and ground connections. While you have the battery cables off you can bang the battery cable crimps with a hammer (or squeeze the cable connectors a little with vice grips) to ensure better continuity (don't do this while the battery is connected or use the battery as a base - don't bang on the battery with a hammer, just the cable crimps).

Other thoughts to collect more indications: try using the Aux start to add the house batteries while attempting a start. See if the generator starts up normal as well.

[ChasRob]

Hi guys, So far

I have replaced the starter with a new one.
Cleaned all the battery cable terminals for house and chassis batteries.
Checked the ends on cables for tightness.
Removed and cleaned the grounds for the engine and the two on the front of the frame for electronics.
Removed the starter relay and cleaned the pins and verified it is working.

The starter still wont engage and acts like a weak battery (solenoid chatters). I have a full charge (13.3V) on the chassis battery and have even tried the emergency start with the house battery boost.

My only thought at this point is that the voltage to the starter relay is weak and won't keep it engaged and I don't know how to test for that.

If anyone has any more ideas on this I'd really appreciate them.
Thanks

[Stevie3508]

ChasR,
Youe need to run a starter draw test (Google it). My first guess would be a bad ground somewhere in the starter curcuit. This is not hard to do but you have to be able to diagnose the problem using proper test procedures and tools (digital multimeter). Throwing parts at a problem does not always end in solving a problem.
Do the proper diagnostics and let us know what you find. I'll bet it is something fairly simple.

[twinboat]

Substute each cable from the battery to its termination point with a jumper cable.

Batt + to solenoid, then Batt - to engine block. If there is a switch bypass that. It could be right in the battery terminal to cable connection.

That will confirm they are good or bad.

Another test is to try starting it and let it hammer a few times. Then go feel all of the connections for a hotter one. Heat is resistance.

[tomwalt]

If using the jumper cables suggested in the previous post don't identify a bad cable/connector, you might want to pull the starter and take it to a parts store for bench testing (should be free for a bench test). Your 'new' starter may have a short in it. Seems/sounds like it has to be in the high current flow components - the start solenoid, cables, or starter.

[geofferyh]

13.3V charge on the battery? Was the battery tested to verify it is good? Load test the battery.

Was the "New" starter new or rebuilt? Rebuilds are not always good out of the box. Bench test it.

To bypass the starter relay simply jumper across the appropriate socket terminals.

Sounds like a bad starter or battery.

[ChasRob]

By this afternoon I had
Cleaned and tightened every battery connection
Tried 2 different fully charged batteries and boost from house batteries
Cleaned and tightened all 4 grounds
Verified the starter relay worked and cleaned the pins

My original thought was the starter solenoid and that is why I changed the starter. I could hear the solenoid kicking in and out and so maybe 30 years ago that would have been a good guess. I kept stumbling across posts about the ignition switch when searching but in those cases everything was dead or would go dead when the key was moved to the start position. No one described my problem of the solenoid kicking in and out.

Began removing the steering column housing and needed to pull the ignition key cylinder to get the top housing off. On a GM you usually find a hole or other keeper to push while turning the key past ACC and it will then come out. Nope. I was turning the key with the battery hooked up (I know, stupid) and the darn thing started.

It must have been that I moved a wire or something and enough contact was made to hold the circuit. We later got the switch apart and a couple of the terminals had very slight burning on the contact points. They must have burned enough to make partial contact, but not to hold it. I'm picking up a new switch at NAPA in the morning.

So, as it turns out, I had the same problem in my W22 ignition switch as the chronic problem in the P32 chassis, just different symptoms.

Thanks everyone for the guidance. It always seems easier to tackle these problems when you know that others are trying to help.

BTW - My 2002 W22 ignition cylinder has a wedge type release on the top about 2" back from the key face that is difficult to see and even more difficult to push.

[speed racer]

Check the voltage at the starter when someone trys to start the engine. If the voltage fluxuates then the problem is in the supply side. If you have a good constant batt. voltage connect the meter to the solenoid side and repeat the test. If you have a good constant batt, voltage there the problem is in the ground. Use the frame rail or neg. side of the batt. for your ground sid of your meter. There should be a ground strap between the frame and engine because the engine is mounted in rubber.

[geofferyh]

Wow.

Any chance you might still know the ignition switch part numbers for the 2003 P32 and 2002 W22?

[ChasRob]

Jeffery

The P32 has a different setup and the ignition switch appears to be midway down the steering column on the top side. Most of the posts I've seen here are on the P32 which seems to have a chronic problem, so bad that GM has a repair kit for it.

The W22 Workhorse I have, classic with a 18" steering wheel, has the switch immediately under the ignition key and is a Delco D1490C. Called NAPA (part# KS6197) and they got it in the next morning. Typical of GM, this switch fits about 50 different car models and the Workhorse is NOT listed among them. It cost me $129.00 and I was OK with that because I wanted it right now, plus being able to compare the old and new one on the spot. They are available on Amazon.com for about $87.00. Supposedly the ignition problem is not as bad in the W22 chassis as it is in the P32.

Edit - Did a search for the P32 and found NAPA part# KS6622 ECHLIN Price 26.92 in another post.