Blower causes engine to quit?
08-11-2002, 09:11 PM
#1
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Car: 89 Formula 350
Engine: 5.7 TPI
Transmission: 700R4
Blower causes engine to quit?
Here is the deal …every time I turn on my A/C blower my tach jumps and the engine starts to run rough then quits. I have disconnected the air compressor thinking that was the problem but nothing changed. The alternator is new and I tested the charging system and the battery, both are fine. Sometimes I can turn on the blower and every thing is fine until I hit a bump then it goes nuts again. Once again the symptoms… when I turn on my A/C blower the tach jumps, speedometer jumps and service engine light flickers (it is on because of a code 36 that I have not fixed yet) I think I have a loose ground or power wire to the ECM but I do not know where they are. Any suggestions? Also when I turn on my wipers the same thing happens but not as bad.
89 Formula 350
350 TPI
Auto
No mods.
89 Formula 350
350 TPI
Auto
No mods.
08-12-2002, 10:31 AM
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I had that exact same problem! This was solved by tightening down a nut on the back of my divers side head that was holding on some ground wires. When my blower was on or I hit bumps the tach would act all crazy and the engine would die. Hope this helps you out.
08-12-2002, 10:56 AM
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Car: 4
Engine: 6
Transmission: 5
Yup, bad connection on either the power side or the ground side of the wiring between the battery and the pass compartment... attempt to draw a high current through said bad connection, voltage drop is too high (i.e. voltage that remains is too low) for ignition system and/or ECM to work...
Things to check: loose ground from engine to chassis like the other post said; bad connection at bulkhead plug where the wires go through the firewall under the brake booster; bad fusible link or cannection at one end or the other of it; bad solder joint where all the big red wires come together, near the steering column; etc.
Not a fun thing to have to troubleshoot, but there's no magic bullet unfortunately.
Things to check: loose ground from engine to chassis like the other post said; bad connection at bulkhead plug where the wires go through the firewall under the brake booster; bad fusible link or cannection at one end or the other of it; bad solder joint where all the big red wires come together, near the steering column; etc.
Not a fun thing to have to troubleshoot, but there's no magic bullet unfortunately.
08-12-2002, 02:11 PM
#5
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Car: 89 Formula 350
Engine: 5.7 TPI
Transmission: 700R4
Thanks guys it sound like a place to start, but i have one more question. Where does the ECM get its power from? Is it one of the fusible links at the battery?
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