The single wire sensor on the driver's side of the block is the sensor that goes to the guage. The other sensor at the thermostat outlet neck is the PCM temp input. That is used by the PCM to determine whether enrichment is required for cold starting, cold engine shift points as well as convertor lock-up once the engine is warm, etc.
Not sure of what your brown wire does but the Blue LS connector pins # 19 and 75 require an ignition switched power supply.
Last edited by Mickeymotormount; 04-13-2013 at 04:43 AM.
'93 Chevy 1500 4X4 ECLB with a '99 Silverado LQ4 6.0 and '99 Escalade 4L60E. SOLD IT!!
New toy: 2001 2500 HD 4X4 Extended Cab Long Bed
John
x2 > What John said.
The CTS (Coolant Temp SENSOR) has a two wire connector and gives the PCM engine temp info. On your 98 the ECT (Engine Coolant Temp SENDER) is a single Green wire that does not go to the PCM---It is what works the gauge.
Jeff
98 GMC RCSB 2wd, 100% internally stock 305, w/twin T-3 junkyard turbos,Ramjet intake w/42lb inj,12200411 PCM. 4675lbs w/me in it. Best time in 5 passes 13.01@110
Right on guys, Thanks for the clarification Jeff on which is which, lt1swap has the thermostat one labeled as ect. Thanks again.
Last edited by shmiet; 04-13-2013 at 08:08 AM.
Back Alley Motorsports 98 GMC
-5.3l LM7 bored to 5.7l Thompson Motorsports -72mm T4 Magnum Turbo
-TU1 Custom Grind cam(spec speed.inc) -799 heads
-.660" Trick Flow dual valve springs -Forged Probe Pistons 3.902" flat top
Posting Permissions
Reply With Quote