Recent Posts

81

Engine/Drivetrain / Re: Transmission dip stick

« Last post by fiddler on March 09, 2026, 04:16:39 pm »

Thanks much I will order one.

82

Engine/Drivetrain / Re: Transmission dip stick

« Last post by VileZambonie on March 09, 2026, 04:00:48 pm »

768023 Pioneer

83

Engine/Drivetrain / Transmission dip stick

« Last post by fiddler on March 08, 2026, 02:53:32 pm »

I have a titled 1974 Chevy c10 stepside.  I say titled because it has so many replacement junkyard parts on it.  I think the engine is from a 1976.  So the cap is no longer on the top of the transmission dip stick and i can't tell how to get a replacement dipstick or how far to insert for a level measurement.  Can anybody out there tell me how to measure a dipstick for length?  From the tip to the cap?  Or tip to bottom of the finger loop, or maybe the top of the finger loop?  The transmission is a th350 as identified by pan bolt pattern.  The engine is a 350.  The instrument cluster is from a 76 I think and uses a voltmeter instead of an ammeter for battery charging indication.  Could be that the dipstick for any year 350s setup could work.  Anybody know??  Thanks in advance

84

Electrical / Re: Fusible link or grounds?

« Last post by fiddler on March 08, 2026, 02:40:38 pm »

Start by removing the battery cables from the battery and thoroughly cleaning the battery posts and the cable connections inside.  In that you had intermittent contact jiggling the battery cables the problem would seem to point in that direction.  Use a wire brush on the inside of the cables.  Not sure what kind of battery you are using, but what you are describing sounds like a corroded battery cable issue.

85

Electrical / Re: TH350C orange test connector use?

« Last post by Scaryfastatx on March 03, 2026, 01:48:30 pm »

Just monitor the OEM engagement

I'm hoping that I can get it working for the TH350 so when I go to a 700R4 it's working nicely

86

Electrical / Re: TH350C orange test connector use?

« Last post by bd on March 03, 2026, 01:29:38 pm »

Are you attempting to control TCC engagement manually or just monitor the OEM engagement protocol?

87

Electrical / Re: TH350C orange test connector use?

« Last post by Scaryfastatx on March 03, 2026, 12:17:24 pm »

For what year model truck are you seeking an answer?

For a 1983 C10 with MV4 (350C) transmission, the orange test connector is used to monitor and verify when 12-volt accessory power is supplied to the transmission TCC circuit through the service brake [applied] switch and low engine vacuum (i.e., high engine load) switch.  There is also a minimum road speed limit switch inside the transmission.  All of the described switches are connected in series with the TCC solenoid.  See diagram.

Thanks for the reply, it's an 81, I think I have everything hooked up correctly according to your diagram

Only difference I see is my 12v supply to the brake switch is pink

My truck had cruise control originally, if that changes anything

I didn't check the brake switch for continuity, will check that next

But was wanting to put a light on the test port to see when I should be engaging the lockup

Sent from my Nokia 8.3 5G using Tapatalk

88

Electrical / Re: TH350C orange test connector use?

« Last post by bd on March 02, 2026, 01:40:25 pm »

For what year model truck are you seeking an answer?

For a 1983 C10 with MV4 (350C) transmission, the orange test connector is used to monitor and verify when 12-volt accessory power is supplied to the transmission TCC circuit through the service brake [applied] switch and low engine vacuum (i.e., high engine load) switch.  There is also a minimum road speed limit switch inside the transmission.  All of the described switches are connected in series with the TCC solenoid.  See diagram.

89

Electrical / TH350C orange test connector use?

« Last post by Scaryfastatx on March 01, 2026, 06:24:03 pm »

Hi all

I'm trying to get my lockup working on my TH350C to squeeze every bit of mpg out of the old Scottsdale

I want to know what kind of behavior I should be seeing on the orange connector:

- 12v when the clutch should be engaging?
- 12v only when the clutch is engaged?

Thanks?